* [PATCH 2/8] n_gsm: uplink SKBs accumulate on list
From: Alan Cox @ 2012-08-13 12:43 UTC (permalink / raw)
To: greg, linux-serial
In-Reply-To: <20120813124254.6125.70371.stgit@localhost.localdomain>
From: Russ Gorby <russ.gorby@intel.com>
gsm_dlci_data_kick will not call any output function if tx_bytes > THRESH_LO
furthermore it will call the output function only once if tx_bytes == 0
If the size of the IP writes are on the order of THRESH_LO
we can get into a situation where skbs accumulate on the outbound list
being starved for events to call the output function.
gsm_dlci_data_kick now calls the sweep function when tx_bytes==0
Signed-off-by: Russ Gorby <russ.gorby@intel.com>
Tested-by: Kappel, LaurentX <laurentx.kappel@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Hay and Water <stable@kernel.org>
---
drivers/tty/n_gsm.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 5c6c2e2..9b0a44d 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -971,16 +971,19 @@ static void gsm_dlci_data_sweep(struct gsm_mux *gsm)
static void gsm_dlci_data_kick(struct gsm_dlci *dlci)
{
unsigned long flags;
+ int sweep;
spin_lock_irqsave(&dlci->gsm->tx_lock, flags);
/* If we have nothing running then we need to fire up */
+ sweep = (dlci->gsm->tx_bytes < TX_THRESH_LO);
if (dlci->gsm->tx_bytes == 0) {
if (dlci->net)
gsm_dlci_data_output_framed(dlci->gsm, dlci);
else
gsm_dlci_data_output(dlci->gsm, dlci);
- } else if (dlci->gsm->tx_bytes < TX_THRESH_LO)
- gsm_dlci_data_sweep(dlci->gsm);
+ }
+ if (sweep)
+ gsm_dlci_data_sweep(dlci->gsm);
spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags);
}
^ permalink raw reply related
* [PATCH 1/8] n_gsm.c: Implement 3GPP27.010 DLC start-up procedure in MUX
From: Alan Cox @ 2012-08-13 12:43 UTC (permalink / raw)
To: greg, linux-serial
From: xiaojin <jin.xiao@intel.com>
In 3GPP27.010 5.8.1, it defined:
The TE multiplexer initiates the establishment of the multiplexer control channel by sending a SABM frame on DLCI 0 using the procedures of clause 5.4.1.
Once the multiplexer channel is established other DLCs may be established using the procedures of clause 5.4.1.
This patch implement 5.8.1 in MUX level, it make sure DLC0 is the first channel to be setup.
[or for those not familiar with the specification: it was possible to try
and open a data connection while the control channel was not yet fully
open, which is a spec violation and confuses some modems]
Signed-off-by: xiaojin <jin.xiao@intel.com>
Tested-by: Yin, Fengwei <fengwei.yin@intel.com>
[tweaked the order we check things and error code]
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: The Horsebox <stable@kernel.org>
---
drivers/tty/n_gsm.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 7a4bf30..5c6c2e2 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -2889,6 +2889,10 @@ static int gsmtty_open(struct tty_struct *tty, struct file *filp)
gsm = gsm_mux[mux];
if (gsm->dead)
return -EL2HLT;
+ /* If DLCI 0 is not yet fully open return an error. This is ok from a locking
+ perspective as we don't have to worry about this if DLCI0 is lost */
+ if (gsm->dlci[0] && gsm->dlci[0]->state != DLCI_OPEN)
+ return -EL2NSYNC;
dlci = gsm->dlci[line];
if (dlci == NULL)
dlci = gsm_dlci_alloc(gsm, line);
^ permalink raw reply related
* Re: [PATCH 07/11] fblog: allow selecting fbs via sysfs and module-parameters
From: Ryan Mallon @ 2012-08-13 0:04 UTC (permalink / raw)
To: David Herrmann
Cc: linux-fbdev, Florian Tobias Schandinat, Greg Kroah-Hartman,
linux-serial, Alan Cox, linux-kernel, Geert Uytterhoeven
In-Reply-To: <1344783205-2384-8-git-send-email-dh.herrmann@googlemail.com>
On 13/08/12 00:53, David Herrmann wrote:
> fblog is mainly useful during boot, reboot, panics and maintenance. In all
> cases you often want to control which monitors are used for console
> output. Moreover, in multi-seat environments it is desireable to reduce
> system-overhead by not drawing the console to all framebuffers. Four
> mechanisms to select framebuffers for fblog are added:
>
> 1) "active" module parameter: This parameter selects whether fblog has
> access to available framebuffer devices. If it is true, then fblog will
> open devices following the rules described below and rendering will take
> place. If it is false, new hotplugged devices will not be activated and no
> more rendering to currently active devices takes place. However, active
> devices will continue rendering after this is set to true again.
>
> 2) "active" sysfs attribute for each fblog object. Reading this value
> returns whether a framebuffer is currently active. Writing it opens/closes
> the framebuffer. This allows runtime control which fbs are used. For
> instance, init can set these to 0 after bootup.
> Note that a framebuffer is only active if this is 1 _and_ the "active"
> module parameter is set to "true".
>
> 3) "activate_on_hotplug" module parameter: This selects whether a device
> is activated by default when hotplugged. This is true by default so new
> devices will be automatically activated.
>
> 4) "main_only" module parameter: This selects what devices are activated
> on hotplug. This has no effect if "activate_on_hotplug" is false.
> Otherwise, if this is true then only fb0 will be activated on hotplug.
> This is false by default.
>
> Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
> ---
> drivers/video/console/fblog.c | 66 ++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 65 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/video/console/fblog.c b/drivers/video/console/fblog.c
> index 1c526c5..aed77dc 100644
> --- a/drivers/video/console/fblog.c
> +++ b/drivers/video/console/fblog.c
> @@ -44,6 +44,9 @@ struct fblog_fb {
>
> static DEFINE_MUTEX(fblog_registration_lock);
> static struct fblog_fb *fblog_fbs[FB_MAX];
> +static bool active = true;
> +static bool activate_on_hotplug = true;
> +static bool main_only = false;
>
> #define to_fblog_dev(_d) container_of(_d, struct fblog_fb, dev)
>
> @@ -63,6 +66,9 @@ static int fblog_open(struct fblog_fb *fb)
> {
> int ret;
>
> + if (!active)
> + return -EPERM;
> +
> mutex_lock(&fb->lock);
>
> if (test_bit(FBLOG_KILLED, &fb->flags)) {
> @@ -115,6 +121,40 @@ static void fblog_close(struct fblog_fb *fb, bool kill_dev)
> mutex_unlock(&fb->lock);
> }
>
> +static ssize_t fblog_dev_active_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct fblog_fb *fb = to_fblog_dev(dev);
> +
> + return snprintf(buf, PAGE_SIZE, "%d\n",
> + !!test_bit(FBLOG_OPEN, &fb->flags));
Nitpick. sprintf is okay here, %d is rarely longer than PAGE_SIZE :-).
> +}
> +
> +static ssize_t fblog_dev_active_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf,
> + size_t count)
> +{
> + struct fblog_fb *fb = to_fblog_dev(dev);
> + unsigned long num;
> + int ret = 0;
> +
> + num = simple_strtoul(buf, NULL, 10);
kstrtoul is preferred these days I think, it also catches errors.
> +
> + mutex_lock(&fb->info->lock);
> + if (num)
> + ret = fblog_open(fb);
> + else
> + fblog_close(fb, false);
> + mutex_unlock(&fb->info->lock);
> +
> + return ret ? ret : count;
Nitpick, you can use gcc's shortcut form of the ? operator here:
return ret ?: count;
> +}
> +
> +static DEVICE_ATTR(active, S_IRUGO | S_IWUSR | S_IWGRP, fblog_dev_active_show,
> + fblog_dev_active_store);
> +
> /*
> * fblog framebuffer list
> * The fblog_fbs[] array contains all currently registered framebuffers. If a
> @@ -148,6 +188,7 @@ static void fblog_do_unregister(struct fb_info *info)
> fblog_fbs[info->node] = NULL;
>
> fblog_close(fb, true);
> + device_remove_file(&fb->dev, &dev_attr_active);
> device_del(&fb->dev);
> put_device(&fb->dev);
> }
> @@ -156,6 +197,7 @@ static void fblog_do_register(struct fb_info *info, bool force)
> {
> struct fblog_fb *fb;
> int ret;
> + bool do_open = true;
>
> fb = fblog_fbs[info->node];
> if (fb && fb->info != info) {
> @@ -186,7 +228,20 @@ static void fblog_do_register(struct fb_info *info, bool force)
> return;
> }
>
> - fblog_open(fb);
> + ret = device_create_file(&fb->dev, &dev_attr_active);
> + if (ret) {
> + pr_err("fblog: cannot create sysfs entry");
Shouldn't need the "fblog: " prefix, since you have pr_fmt defined.
> + /* do not open fb if we cannot create control file */
> + do_open = false;
> + }
> +
> + if (!activate_on_hotplug)
> + do_open = false;
> + if (main_only && info->node != 0)
> + do_open = false;
> +
> + if (do_open)
> + fblog_open(fb);
> }
>
> static void fblog_register(struct fb_info *info, bool force)
> @@ -321,6 +376,15 @@ static void __exit fblog_exit(void)
> }
> }
>
> +module_param(active, bool, S_IRUGO | S_IWUSR | S_IWGRP);
> +MODULE_PARM_DESC(active, "Activate fblog rendering");
> +
> +module_param(activate_on_hotplug, bool, S_IRUGO | S_IWUSR | S_IWGRP);
> +MODULE_PARM_DESC(activate_on_hotplug, "Activate fblog on hotplugged devices");
> +
> +module_param(main_only, bool, S_IRUGO);
> +MODULE_PARM_DESC(main_only, "Activate fblog by default only on main devices");
> +
> module_init(fblog_init);
> module_exit(fblog_exit);
> MODULE_LICENSE("GPL");
>
^ permalink raw reply
* Re: [PATCH 06/11] fblog: open fb on registration
From: Ryan Mallon @ 2012-08-13 0:00 UTC (permalink / raw)
To: David Herrmann
Cc: linux-fbdev, Florian Tobias Schandinat, Greg Kroah-Hartman,
linux-serial, Alan Cox, linux-kernel, Geert Uytterhoeven
In-Reply-To: <1344783205-2384-7-git-send-email-dh.herrmann@googlemail.com>
On 13/08/12 00:53, David Herrmann wrote:
> This opens the framebuffer upon registration so we can use it for
> drawing-operations. On unregistration we close it again.
>
> While opening/closing or accessing the fb in any other way, we must hold
> the fb-mutex. However, since the notifiers are often called with the mutex
> already held, we cannot lock it _after_ taking the
> fblog_registration_lock. Therefore, we require the caller to make sure the
> fb-mutex is held.
>
> Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
Some comments below,
~Ryan
> ---
> drivers/video/console/fblog.c | 94 ++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 93 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/video/console/fblog.c b/drivers/video/console/fblog.c
> index 279f4d8..1c526c5 100644
> --- a/drivers/video/console/fblog.c
> +++ b/drivers/video/console/fblog.c
> @@ -32,12 +32,14 @@
>
> enum fblog_flags {
> FBLOG_KILLED,
> + FBLOG_OPEN,
> };
>
> struct fblog_fb {
> unsigned long flags;
> struct fb_info *info;
> struct device dev;
> + struct mutex lock;
> };
>
> static DEFINE_MUTEX(fblog_registration_lock);
> @@ -46,6 +48,74 @@ static struct fblog_fb *fblog_fbs[FB_MAX];
> #define to_fblog_dev(_d) container_of(_d, struct fblog_fb, dev)
>
> /*
> + * fblog_open/close()
> + * These functions manage access to the underlying framebuffer. While opened, we
> + * have a valid reference to the fb and can use it for drawing operations. When
> + * the fb is unregistered, we drop our reference and close the fb so it can get
> + * deleted properly. We also mark it as dead so no further fblog_open() call
> + * will succeed.
> + * Both functions must be called with the fb->info->lock mutex held! But make
> + * sure to lock it _before_ locking the fblog-registration-lock. Otherwise, we
> + * will dead-lock with fb-registration.
> + */
> +
> +static int fblog_open(struct fblog_fb *fb)
> +{
> + int ret;
> +
> + mutex_lock(&fb->lock);
> +
> + if (test_bit(FBLOG_KILLED, &fb->flags)) {
> + ret = -ENODEV;
> + goto unlock;
> + }
> +
> + if (test_bit(FBLOG_OPEN, &fb->flags)) {
> + ret = 0;
> + goto unlock;
> + }
> +
> + if (!try_module_get(fb->info->fbops->owner)) {
> + ret = -ENODEV;
> + goto out_killed;
> + }
> +
> + if (fb->info->fbops->fb_open && fb->info->fbops->fb_open(fb->info, 0)) {
Should propagate the error here:
if (fb->info->fbops->fb_open) {
ret = fb->info->fbops->fb_open(fb->info, 0);
if (ret)
gotou out_unref;
}
> + ret = -EIO;
> + goto out_unref;
> + }
> +
> + set_bit(FBLOG_OPEN, &fb->flags);
> + mutex_unlock(&fb->lock);
> + return 0;
> +
> +out_unref:
> + module_put(fb->info->fbops->owner);
> +out_killed:
> + set_bit(FBLOG_KILLED, &fb->flags);
> +unlock:
> + mutex_unlock(&fb->lock);
> + return ret;
> +}
> +
> +static void fblog_close(struct fblog_fb *fb, bool kill_dev)
> +{
> + mutex_lock(&fb->lock);
> +
> + if (test_bit(FBLOG_OPEN, &fb->flags)) {
> + if (fb->info->fbops->fb_release)
> + fb->info->fbops->fb_release(fb->info, 0);
> + module_put(fb->info->fbops->owner);
> + clear_bit(FBLOG_OPEN, &fb->flags);
> + }
> +
> + if (kill_dev)
> + set_bit(FBLOG_KILLED, &fb->flags);
> +
> + mutex_unlock(&fb->lock);
> +}
> +
> +/*
> * fblog framebuffer list
> * The fblog_fbs[] array contains all currently registered framebuffers. If a
> * framebuffer is in that list, we always must make sure that we own a reference
> @@ -77,6 +147,7 @@ static void fblog_do_unregister(struct fb_info *info)
>
> fblog_fbs[info->node] = NULL;
>
> + fblog_close(fb, true);
> device_del(&fb->dev);
> put_device(&fb->dev);
device_unregister?
> }
> @@ -99,6 +170,7 @@ static void fblog_do_register(struct fb_info *info, bool force)
> return;
>
> fb->info = info;
> + mutex_init(&fb->lock);
> __module_get(THIS_MODULE);
> device_initialize(&fb->dev);
> fb->dev.class = fb_class;
> @@ -113,6 +185,8 @@ static void fblog_do_register(struct fb_info *info, bool force)
> put_device(&fb->dev);
> return;
> }
> +
> + fblog_open(fb);
> }
This function should really return an errno value.
>
> static void fblog_register(struct fb_info *info, bool force)
> @@ -134,6 +208,7 @@ static int fblog_event(struct notifier_block *self, unsigned long action,
> {
> struct fb_event *event = data;
> struct fb_info *info = event->info;
> + struct fblog_fb *fb;
>
> switch(action) {
> case FB_EVENT_FB_REGISTERED:
> @@ -145,8 +220,21 @@ static int fblog_event(struct notifier_block *self, unsigned long action,
> case FB_EVENT_FB_UNREGISTERED:
> /* This is called when a low-level system driver unregisters a
> * framebuffer. The registration lock is held but the console
> - * lock might not be held. */
> + * lock might not be held. The fb-lock is not held, either! */
> + mutex_lock(&info->lock);
> fblog_unregister(info);
> + mutex_unlock(&info->lock);
> + break;
> + case FB_EVENT_FB_UNBIND:
> + /* Called directly before unregistering an FB. The FB is still
> + * valid here and the registration lock is held but the console
> + * lock might not be held (really?). */
> + mutex_lock(&fblog_registration_lock);
> + fb = fblog_fbs[info->node];
> + mutex_unlock(&fblog_registration_lock);
> +
> + if (fb)
> + fblog_close(fb, true);
> break;
> }
>
> @@ -163,7 +251,9 @@ static void fblog_scan(void)
> if (!info || IS_ERR(info))
> continue;
>
> + mutex_lock(&info->lock);
> fblog_register(info, false);
> + mutex_unlock(&info->lock);
>
> /* There is a very subtle race-condition. Even though we might
> * own a reference to the fb, it may still get unregistered
> @@ -224,7 +314,9 @@ static void __exit fblog_exit(void)
> if (!info || IS_ERR(info))
> continue;
>
> + mutex_lock(&info->lock);
> fblog_unregister(info);
> + mutex_unlock(&info->lock);
> put_fb_info(info);
> }
> }
>
^ permalink raw reply
* Re: [PATCH 05/11] fblog: register one fblog object per framebuffer
From: Ryan Mallon @ 2012-08-12 23:54 UTC (permalink / raw)
To: David Herrmann
Cc: linux-fbdev, Florian Tobias Schandinat, Greg Kroah-Hartman,
linux-serial, Alan Cox, linux-kernel, Geert Uytterhoeven
In-Reply-To: <1344783205-2384-6-git-send-email-dh.herrmann@googlemail.com>
On 13/08/12 00:53, David Herrmann wrote:
> One fblog object is associated to each registered framebuffer. This way,
> we can draw the console to each framebuffer. When a framebuffer driver
> unregisters a framebuffer, we also unregister our fblog object. That is,
> our lifetime is coupled to the lifetime of the framebuffer. However, this
> does not mean that we are always active. On the contrary, we do not even
> own a reference to the framebuffer. We don't need it as we are notified
> _before_ the last reference is dropped.
>
> However, if other users have a reference to our object, we simply mark it
> as dead when the associated framebuffer dies and leave it alone. When the
> last reference is dropped, it will be automatically freed.
>
> Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
Hi David,
Quick review below.
Thanks,
~Ryan
> ---
> drivers/video/console/fblog.c | 195 ++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 195 insertions(+)
>
> diff --git a/drivers/video/console/fblog.c b/drivers/video/console/fblog.c
> index fb39737..279f4d8 100644
> --- a/drivers/video/console/fblog.c
> +++ b/drivers/video/console/fblog.c
> @@ -23,15 +23,210 @@
> * all fblog instances before running other graphics applications.
> */
>
> +#define pr_fmt(_fmt) KBUILD_MODNAME ": " _fmt
> +
> +#include <linux/device.h>
> +#include <linux/fb.h>
> #include <linux/module.h>
> +#include <linux/mutex.h>
> +
> +enum fblog_flags {
> + FBLOG_KILLED,
> +};
> +
> +struct fblog_fb {
> + unsigned long flags;
Are more flags added in later patches? If not, why not just have:
bool is_killed;
?
> + struct fb_info *info;
> + struct device dev;
> +};
> +
> +static DEFINE_MUTEX(fblog_registration_lock);
> +static struct fblog_fb *fblog_fbs[FB_MAX];
> +
> +#define to_fblog_dev(_d) container_of(_d, struct fblog_fb, dev)
> +
> +/*
> + * fblog framebuffer list
> + * The fblog_fbs[] array contains all currently registered framebuffers. If a
> + * framebuffer is in that list, we always must make sure that we own a reference
> + * to it. If it is added through the notifier callbacks, then this is always
> + * guaranteed.
> + * We are only interested in registered framebuffers. That is, if a driver calls
> + * unregister_framebuffer() we directly unlink it from our list. This guarantees
> + * that the associated fb_info is always valid. However, we might still have
> + * pending users so we mark it as dead so no further framebuffer actions are
> + * done. If the last user then drops a reference, the memory gets freed
> + * automatically.
> + */
> +
> +static void fblog_release(struct device *dev)
> +{
> + struct fblog_fb *fb = to_fblog_dev(dev);
> +
> + kfree(fb);
> + module_put(THIS_MODULE);
> +}
> +
> +static void fblog_do_unregister(struct fb_info *info)
> +{
> + struct fblog_fb *fb;
> +
> + fb = fblog_fbs[info->node];
> + if (!fb || fb->info != info)
> + return;
> +
> + fblog_fbs[info->node] = NULL;
> +
> + device_del(&fb->dev);
> + put_device(&fb->dev);
device_unregister?
> +}
> +
> +static void fblog_do_register(struct fb_info *info, bool force)
> +{
> + struct fblog_fb *fb;
> + int ret;
> +
> + fb = fblog_fbs[info->node];
> + if (fb && fb->info != info) {
> + if (!force)
> + return;
> +
> + fblog_do_unregister(fb->info);
> + }
> +
> + fb = kzalloc(sizeof(*fb), GFP_KERNEL);
> + if (!fb)
> + return;
> +
> + fb->info = info;
> + __module_get(THIS_MODULE);
> + device_initialize(&fb->dev);
> + fb->dev.class = fb_class;
> + fb->dev.release = fblog_release;
> + dev_set_name(&fb->dev, "fblog%d", info->node);
> + fblog_fbs[info->node] = fb;
> +
> + ret = device_add(&fb->dev);
> + if (ret) {
> + fblog_fbs[info->node] = NULL;
> + set_bit(FBLOG_KILLED, &fb->flags);
> + put_device(&fb->dev);
kfree(fb); ?
> + return;
> + }
> +}
> +
> +static void fblog_register(struct fb_info *info, bool force)
> +{
> + mutex_lock(&fblog_registration_lock);
> + fblog_do_register(info, force);
> + mutex_unlock(&fblog_registration_lock);
> +}
> +
> +static void fblog_unregister(struct fb_info *info)
> +{
> + mutex_lock(&fblog_registration_lock);
> + fblog_do_unregister(info);
> + mutex_unlock(&fblog_registration_lock);
> +}
This locking is needlessly heavy, and could easily pushed down into the
fb_do_(un)register functions. It would also help make it clear exactly
what the lock is protecting.
> +static int fblog_event(struct notifier_block *self, unsigned long action,
> + void *data)
> +{
> + struct fb_event *event = data;
> + struct fb_info *info = event->info;
> +
> + switch(action) {
> + case FB_EVENT_FB_REGISTERED:
> + /* This is called when a low-level system driver registers a new
> + * framebuffer. The registration lock is held but the console
> + * lock might not be held when this is called. */
Nitpick:
/*
* The Linux kernel multi-line
* comment style looks like
* this.
*/
> + fblog_register(info, true);
> + break;
> + case FB_EVENT_FB_UNREGISTERED:
> + /* This is called when a low-level system driver unregisters a
> + * framebuffer. The registration lock is held but the console
> + * lock might not be held. */
> + fblog_unregister(info);
> + break;
> + }
> +
> + return 0;
> +}
> +
> +static void fblog_scan(void)
> +{
> + unsigned int i;
> + struct fb_info *info, *tmp;
> +
> + for (i = 0; i < FB_MAX; ++i) {
> + info = get_fb_info(i);
> + if (!info || IS_ERR(info))
Nitpick:
if (IS_ERR_OR_NULL(info))
> + continue;
> +
> + fblog_register(info, false);
This function should really return a value to indicate if it failed.
There is no point continuing if it didn't register anything.
> + /* There is a very subtle race-condition. Even though we might
> + * own a reference to the fb, it may still get unregistered
> + * between our call from get_fb_info() and fblog_register().
> + * Therefore, we simply check whether the same fb still is
> + * registered by calling get_fb_info() again. Only if they
> + * differ we know that it got unregistered, therefore, we
> + * call fblog_unregister() with the old pointer. */
> +
> + tmp = get_fb_info(i);
> + if (tmp && !IS_ERR(tmp))
> + put_fb_info(tmp);
> + if (tmp != info)
> + fblog_unregister(info);
It would be better to fix this issue properly. Calling fblog_unregister
here also looks unsafe if the call to fblog_register above failed.
> + /* Here we either called fblog_unregister() and therefore do not
> + * need any reference to the fb, or we can be sure that the FB
> + * is registered and FB_EVENT_FB_UNREGISTERED will be called
> + * before the last reference is dropped. Hence, we can drop our
> + * reference here. */
This seems a slightly odd reasoning. Why would you not hold a reference
to something you are using?
> + put_fb_info(info);
> + }
> +}
> +
> +static struct notifier_block fblog_notifier = {
> + .notifier_call = fblog_event,
> +};
>
> static int __init fblog_init(void)
> {
> + int ret;
> +
> + ret = fb_register_client(&fblog_notifier);
> + if (ret) {
> + pr_err("cannot register framebuffer notifier\n");
> + return ret;
> + }
> +
> + fblog_scan();
> +
> return 0;
> }
>
> static void __exit fblog_exit(void)
> {
> + unsigned int i;
> + struct fb_info *info;
> +
> + fb_unregister_client(&fblog_notifier);
> +
> + /* We scan through the whole registered_fb array here instead of
> + * fblog_fbs because we need to get the device lock _before_ the
> + * fblog-registration-lock. */
> +
> + for (i = 0; i < FB_MAX; ++i) {
> + info = get_fb_info(i);
> + if (!info || IS_ERR(info))
> + continue;
> +
> + fblog_unregister(info);
Given the description of the get_fb_info/fblog_register race above, can
this unregister the wrong framebuffer?
> + put_fb_info(info);
> + }
> }
>
> module_init(fblog_init);
>
^ permalink raw reply
* Re: [PATCH 03/11] fblog: new framebuffer kernel log dummy driver
From: Ryan Mallon @ 2012-08-12 23:34 UTC (permalink / raw)
To: David Herrmann
Cc: linux-fbdev, Florian Tobias Schandinat, Greg Kroah-Hartman,
linux-serial, Alan Cox, linux-kernel, Geert Uytterhoeven
In-Reply-To: <1344783205-2384-4-git-send-email-dh.herrmann@googlemail.com>
On 13/08/12 00:53, David Herrmann wrote:
> Fblog displays all kernel log messages on all connected framebuffers. It
> replaces fbcon when CONFIG_VT=n is selected. Its main purpose is to debug
> boot problems by displaying the whole boot log on the screen. This patch
> provides the first dummy module-init/deinit functions.
>
> As it uses all the font and fb functions I placed it in
> drivers/video/console. However, this means that we need to move the check
> for CONFIG_VT in Makefile/Kconfig from drivers/video into
> drivers/video/console as fblog does not depend on CONFIG_VT.
>
> Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
Hi David,
Couple of comments below.
~Ryan
> config VGA_CONSOLE
> bool "VGA text console" if EXPERT || !X86
> - depends on !4xx && !8xx && !SPARC && !M68K && !PARISC && !FRV && !SUPERH && !BLACKFIN && !AVR32 && !MN10300 && (!ARM || ARCH_FOOTBRIDGE || ARCH_INTEGRATOR || ARCH_NETWINDER)
> + depends on VT && !4xx && !8xx && !SPARC && !M68K && !PARISC && !FRV && !SUPERH && !BLACKFIN && !AVR32 && !MN10300 && (!ARM || ARCH_FOOTBRIDGE || ARCH_INTEGRATOR || ARCH_NETWINDER)
> default y
> help
> Saying Y here will allow you to use Linux in text mode through a
> @@ -45,7 +45,7 @@ config VGACON_SOFT_SCROLLBACK_SIZE
> screenfuls of scrollback buffer
You could just place all of the CONFIG_VT options inside an if VT and
then the new fblog options in the else case rather than modifying all of
the (already overly long) depends statements.
> +config FBLOG
> + tristate "Framebuffer Kernel Log Driver"
> + depends on !VT && FB
> + default n
Default n is not required, all options are default n unless otherwise
specified. I don't think you need the dependency on FB either, since
this file should only get included if CONFIG_FB is set?
> + help
> + This driver displays all kernel log messages on all connected
> + framebuffers. It is mutually exclusive with CONFIG_FRAMEBUFFER_CONSOLE
> + and CONFIG_VT. It was mainly created for debugging purposes when
> + CONFIG_VT is not selected but you still want kernel boot messages on
> + the screen.
Do command line options exist to specify screens to write the debug log
to? It might be a useful feature to have.
~Ryan
^ permalink raw reply
* Re: [PATCH 00/11] fblog: Framebuffer kernel log driver v4
From: Florian Tobias Schandinat @ 2012-08-12 15:28 UTC (permalink / raw)
To: David Herrmann
Cc: linux-fbdev, Greg Kroah-Hartman, linux-serial, Alan Cox,
linux-kernel, Geert Uytterhoeven
In-Reply-To: <1344783205-2384-1-git-send-email-dh.herrmann@googlemail.com>
On 08/12/2012 02:53 PM, David Herrmann wrote:
> Hi
>
> This is revision 4 of the fblog driver. It is a replacement for fbcon for
> systems that do not want/need CONFIG_VT. It simply prints the kernel-log to all
> connected framebuffers. Previous versions are available here:
> v3: http://thread.gmane.org/gmane.linux.kernel/1328164
> v2: http://thread.gmane.org/gmane.linux.serial/8133
> v1: http://marc.info/?l=linux-kernel&m=133988465602225&w=2
>
> This patchset is based on linux-next.
>
> Changes from previous version:
> - Changed mailinglist to linux-fbdev instead of linux-serial
> - Added "main_only" and "activate_on_hotplug" module parameters to provide
> more fine-grained control over which framebuffers are used
>
> As always simply remove the !VT dependency if you want to test this with VTs
> enabled. Some more background information on deprecating CONFIG_VT can be found
> here:
> http://dvdhrm.wordpress.com/2012/08/12/killing-off-config_vt/
>
> I am still looking for someone who is willing to push this to linux-next through
> his or her tree. Feedback is much appreciated!
I'll take care of this. But I'm currently very busy writing a thesis, so
it could take some time. It would be great if someone would find time to
give this a complete thorough review.
Thanks,
Florian Tobias Schandinat
>
> Thanks
> David
>
> David Herrmann (11):
> fbcon: move update_attr() into separate source file
> fbcon: move bit_putcs() into separate source file
> fblog: new framebuffer kernel log dummy driver
> fbdev: export get_fb_info()/put_fb_info()
> fblog: register one fblog object per framebuffer
> fblog: open fb on registration
> fblog: allow selecting fbs via sysfs and module-parameters
> fblog: cache framebuffer BLANK and SUSPEND states
> fblog: register console driver
> fblog: draw console to framebuffers
> MAINTAINERS: add fblog entry
>
> MAINTAINERS | 6 +
> drivers/video/Kconfig | 5 +-
> drivers/video/Makefile | 2 +-
> drivers/video/console/Kconfig | 37 ++-
> drivers/video/console/Makefile | 4 +-
> drivers/video/console/bitblit.c | 149 +--------
> drivers/video/console/fbcon.h | 5 +-
> drivers/video/console/fbdraw.c | 171 ++++++++++
> drivers/video/console/fbdraw.h | 30 ++
> drivers/video/console/fblog.c | 691 ++++++++++++++++++++++++++++++++++++++++
> drivers/video/fbmem.c | 6 +-
> include/linux/fb.h | 3 +
> 12 files changed, 951 insertions(+), 158 deletions(-)
> create mode 100644 drivers/video/console/fbdraw.c
> create mode 100644 drivers/video/console/fbdraw.h
> create mode 100644 drivers/video/console/fblog.c
>
^ permalink raw reply
* [PATCH 11/11] MAINTAINERS: add fblog entry
From: David Herrmann @ 2012-08-12 14:53 UTC (permalink / raw)
To: linux-fbdev
Cc: Florian Tobias Schandinat, Greg Kroah-Hartman, linux-serial,
Alan Cox, linux-kernel, Geert Uytterhoeven, David Herrmann
In-Reply-To: <1344783205-2384-1-git-send-email-dh.herrmann@googlemail.com>
Add myself as maintainer for the fblog driver to the MAINTAINERS file.
Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
---
MAINTAINERS | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 375b1fd..40a10b54 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2895,6 +2895,12 @@ F: drivers/video/
F: include/video/
F: include/linux/fb.h
+FRAMEBUFFER LOG DRIVER
+M: David Herrmann <dh.herrmann@googlemail.com>
+L: linux-fbdev@vger.kernel.org
+S: Maintained
+F: drivers/video/console/fblog.c
+
FREESCALE DMA DRIVER
M: Li Yang <leoli@freescale.com>
M: Zhang Wei <zw@zh-kernel.org>
--
1.7.11.4
^ permalink raw reply related
* [PATCH 10/11] fblog: draw console to framebuffers
From: David Herrmann @ 2012-08-12 14:53 UTC (permalink / raw)
To: linux-fbdev
Cc: Florian Tobias Schandinat, Greg Kroah-Hartman, linux-serial,
Alan Cox, linux-kernel, Geert Uytterhoeven, David Herrmann
In-Reply-To: <1344783205-2384-1-git-send-email-dh.herrmann@googlemail.com>
If not disabled or suspended, we now blit the console data to each
framebuffer. We only redraw on changes to avoid consuming too much CPU
power.
This isn't optimized for speed, currently. However, fblog is mainly used
for debugging purposes so this can be optimized later.
Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
---
drivers/video/console/fblog.c | 110 +++++++++++++++++++++++++++++++++++++++++-
1 file changed, 109 insertions(+), 1 deletion(-)
diff --git a/drivers/video/console/fblog.c b/drivers/video/console/fblog.c
index 2e39577..25bb63d 100644
--- a/drivers/video/console/fblog.c
+++ b/drivers/video/console/fblog.c
@@ -28,8 +28,11 @@
#include <linux/console.h>
#include <linux/device.h>
#include <linux/fb.h>
+#include <linux/font.h>
+#include <linux/kd.h>
#include <linux/module.h>
#include <linux/mutex.h>
+#include "fbdraw.h"
/**
* struct fblog_buf: Console text buffer
@@ -66,6 +69,7 @@ struct fblog_fb {
struct device dev;
struct mutex lock;
struct fblog_buf buf;
+ struct console_font font;
};
static DEFINE_MUTEX(fblog_registration_lock);
@@ -176,6 +180,61 @@ static void fblog_buf_write(struct fblog_buf *buf, const char *str, size_t len)
}
}
+static void fblog_redraw_clear(struct fblog_fb *fb)
+{
+ struct fb_fillrect region;
+ struct fb_info *info = fb->info;
+
+ region.color = 0;
+ region.dx = 0;
+ region.dy = 0;
+ region.width = info->var.xres;
+ region.height = info->var.yres;
+ region.rop = ROP_COPY;
+
+ info->fbops->fb_fillrect(info, ®ion);
+}
+
+static void fblog_redraw(struct fblog_fb *fb)
+{
+ size_t i;
+
+ if (!active)
+ return;
+
+ mutex_lock(&fb->lock);
+ if (!test_bit(FBLOG_OPEN, &fb->flags) ||
+ test_bit(FBLOG_SUSPENDED, &fb->flags) ||
+ test_bit(FBLOG_BLANKED, &fb->flags)) {
+ mutex_unlock(&fb->lock);
+ return;
+ }
+
+ fblog_redraw_clear(fb);
+
+ for (i = 0; i < fb->buf.height; ++i) {
+ fbdraw_font(fb->info, &fb->font, false, 0, i, 7, 0, 0,
+ fb->buf.lines[i], fb->buf.width);
+ }
+
+ mutex_unlock(&fb->lock);
+}
+
+static void fblog_refresh(struct fblog_fb *fb)
+{
+ unsigned int width, height;
+
+ mutex_lock(&fb->lock);
+ if (test_bit(FBLOG_OPEN, &fb->flags)) {
+ width = fb->info->var.xres / fb->font.width;
+ height = fb->info->var.yres / fb->font.height;
+ fblog_buf_resize(&fb->buf, width, height);
+ }
+ mutex_unlock(&fb->lock);
+
+ fblog_redraw(fb);
+}
+
/*
* fblog_open/close()
* These functions manage access to the underlying framebuffer. While opened, we
@@ -192,6 +251,10 @@ static int fblog_open(struct fblog_fb *fb)
{
static const char init_str[] = "Framebuffer log initialized\n";
int ret;
+ struct fb_var_screeninfo var;
+ const struct fb_videomode *mode;
+ unsigned int width, height;
+ const struct font_desc *font;
if (!active)
return -EPERM;
@@ -208,6 +271,13 @@ static int fblog_open(struct fblog_fb *fb)
goto unlock;
}
+ font = get_default_font(var.xres, var.yres, fb->info->pixmap.blit_x,
+ fb->info->pixmap.blit_y);
+ if (!font) {
+ ret = -ENODEV;
+ goto unlock;
+ }
+
if (!try_module_get(fb->info->fbops->owner)) {
ret = -ENODEV;
goto out_killed;
@@ -218,10 +288,22 @@ static int fblog_open(struct fblog_fb *fb)
goto out_unref;
}
- fblog_buf_resize(&fb->buf, 80, 24);
+ var = fb->info->var;
+ mode = fb_find_best_mode(&var, &fb->info->modelist);
+ var.activate = FB_ACTIVATE_NOW | FB_ACTIVATE_FORCE;
+ fb_set_var(fb->info, &var);
+
+ fb->font.width = font->width;
+ fb->font.height = font->height;
+ fb->font.data = (void*)font->data;
+
+ width = var.xres / fb->font.width;
+ height = var.yres / fb->font.height;
+ fblog_buf_resize(&fb->buf, width, height);
fblog_buf_write(&fb->buf, init_str, sizeof(init_str) - 1);
set_bit(FBLOG_OPEN, &fb->flags);
mutex_unlock(&fb->lock);
+ fblog_redraw(fb);
return 0;
out_unref:
@@ -460,6 +542,31 @@ static int fblog_event(struct notifier_block *self, unsigned long action,
else
set_bit(FBLOG_BLANKED, &fb->flags);
break;
+ case FB_EVENT_MODE_DELETE:
+ /* This is sent when a video mode is removed. The current video
+ * mode is never removed! The console lock is held while this is
+ * called. */
+ /* fallthrough */
+ case FB_EVENT_NEW_MODELIST:
+ /* This is sent when the modelist got changed. The console-lock
+ * is held and we should reset the mode. */
+ /* fallthrough */
+ case FB_EVENT_MODE_CHANGE_ALL:
+ /* This is the same as below but notifies us that the user used
+ * the FB_ACTIVATE_ALL flag when setting the video mode. */
+ /* fallthrough */
+ case FB_EVENT_MODE_CHANGE:
+ /* This is called when the _user_ changes the video mode via
+ * ioctls. It is not sent, when the kernel changes the mode
+ * internally. This callback is called inside fb_set_var() so
+ * the console lock is held. */
+ mutex_lock(&fblog_registration_lock);
+ fb = fblog_fbs[info->node];
+ mutex_unlock(&fblog_registration_lock);
+
+ if (fb)
+ fblog_refresh(fb);
+ break;
}
return 0;
@@ -516,6 +623,7 @@ static void fblog_con_write(struct console *con, const char *buf,
for (i = 0; i < FB_MAX; ++i) {
if (fblog_fbs[i]) {
fblog_buf_write(&fblog_fbs[i]->buf, buf, len);
+ fblog_redraw(fblog_fbs[i]);
}
}
mutex_unlock(&fblog_registration_lock);
--
1.7.11.4
^ permalink raw reply related
* [PATCH 09/11] fblog: register console driver
From: David Herrmann @ 2012-08-12 14:53 UTC (permalink / raw)
To: linux-fbdev
Cc: Florian Tobias Schandinat, Greg Kroah-Hartman, linux-serial,
Alan Cox, linux-kernel, Geert Uytterhoeven, David Herrmann
In-Reply-To: <1344783205-2384-1-git-send-email-dh.herrmann@googlemail.com>
We want to print the kernel log to all FBs so we need a console driver.
This registers the driver on startup and writes all messages to all
registered fblog instances.
We cannot share a console buffer between FBs because they might have
different resolutions. Therefore, we create one buffer per object. We
destroy the buffer during close() so we do not waste memory if it is not
used.
Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
---
drivers/video/console/fblog.c | 150 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 150 insertions(+)
diff --git a/drivers/video/console/fblog.c b/drivers/video/console/fblog.c
index 8bcd0ce..2e39577 100644
--- a/drivers/video/console/fblog.c
+++ b/drivers/video/console/fblog.c
@@ -25,11 +25,34 @@
#define pr_fmt(_fmt) KBUILD_MODNAME ": " _fmt
+#include <linux/console.h>
#include <linux/device.h>
#include <linux/fb.h>
#include <linux/module.h>
#include <linux/mutex.h>
+/**
+ * struct fblog_buf: Console text buffer
+ *
+ * Each framebuffer has its own text buffer which contains all characters that
+ * are currently printed on screen. The buffers might have different sizes and
+ * can be resized during runtime. When the buffer content changes, we redraw the
+ * screen.
+ *
+ * width: Width of buffer in characters
+ * height: Height of buffer in characters
+ * lines: Array of lines
+ * pos_x: Cursor x-position
+ * pos_y: Cursor y-position
+ */
+struct fblog_buf {
+ size_t width;
+ size_t height;
+ u16 **lines;
+ size_t pos_x;
+ size_t pos_y;
+};
+
enum fblog_flags {
FBLOG_KILLED,
FBLOG_OPEN,
@@ -42,6 +65,7 @@ struct fblog_fb {
struct fb_info *info;
struct device dev;
struct mutex lock;
+ struct fblog_buf buf;
};
static DEFINE_MUTEX(fblog_registration_lock);
@@ -52,6 +76,106 @@ static bool main_only = false;
#define to_fblog_dev(_d) container_of(_d, struct fblog_fb, dev)
+static void fblog_buf_resize(struct fblog_buf *buf, size_t width,
+ size_t height)
+{
+ u16 **lines = NULL;
+ size_t i, j, minw, minh;
+
+ if (buf->height == height && buf->width == width)
+ return;
+
+ if (width && height) {
+ lines = kzalloc(height * sizeof(char *), GFP_KERNEL);
+ if (!lines)
+ return;
+
+ for (i = 0; i < height; ++i) {
+ lines[i] = kzalloc(width * sizeof(u16), GFP_KERNEL);
+ if (!lines[i]) {
+ while (i--)
+ kfree(lines[i]);
+ return;
+ }
+ }
+
+ /* copy old lines */
+ minw = min(width, buf->width);
+ minh = min(height, buf->height);
+ if (height >= buf->height)
+ i = 0;
+ else
+ i = buf->height - height;
+
+ for (j = 0; j < minh; ++i, ++j)
+ memcpy(lines[j], buf->lines[i], minw * sizeof(u16));
+ } else {
+ width = 0;
+ height = 0;
+ }
+
+ for (i = 0; i < buf->height; ++i)
+ kfree(buf->lines[i]);
+ kfree(buf->lines);
+
+ buf->lines = lines;
+ buf->width = width;
+ buf->height = height;
+}
+
+static void fblog_buf_deinit(struct fblog_buf *buf)
+{
+ fblog_buf_resize(buf, 0, 0);
+}
+
+static void fblog_buf_rotate(struct fblog_buf *buf)
+{
+ u16 *line;
+
+ if (!buf->height)
+ return;
+
+ line = buf->lines[0];
+ memset(line, 0, sizeof(u16) * buf->width);
+
+ memmove(buf->lines, &buf->lines[1], sizeof(char*) * (buf->height - 1));
+ buf->lines[buf->height - 1] = line;
+}
+
+static void fblog_buf_write(struct fblog_buf *buf, const char *str, size_t len)
+{
+ char c;
+
+ if (!buf->height)
+ return;
+
+ while (len--) {
+ c = *str++;
+
+ if (c == 0)
+ c = '?';
+
+ if (c == '\n') {
+ buf->pos_x = 0;
+ if (++buf->pos_y >= buf->height) {
+ buf->pos_y = buf->height - 1;
+ fblog_buf_rotate(buf);
+ }
+ } else {
+ if (buf->pos_x >= buf->width) {
+ buf->pos_x = 0;
+ ++buf->pos_y;
+ }
+ if (buf->pos_y >= buf->height) {
+ buf->pos_y = buf->height - 1;
+ fblog_buf_rotate(buf);
+ }
+
+ buf->lines[buf->pos_y][buf->pos_x++] = c;
+ }
+ }
+}
+
/*
* fblog_open/close()
* These functions manage access to the underlying framebuffer. While opened, we
@@ -66,6 +190,7 @@ static bool main_only = false;
static int fblog_open(struct fblog_fb *fb)
{
+ static const char init_str[] = "Framebuffer log initialized\n";
int ret;
if (!active)
@@ -93,6 +218,8 @@ static int fblog_open(struct fblog_fb *fb)
goto out_unref;
}
+ fblog_buf_resize(&fb->buf, 80, 24);
+ fblog_buf_write(&fb->buf, init_str, sizeof(init_str) - 1);
set_bit(FBLOG_OPEN, &fb->flags);
mutex_unlock(&fb->lock);
return 0;
@@ -115,6 +242,7 @@ static void fblog_close(struct fblog_fb *fb, bool kill_dev)
fb->info->fbops->fb_release(fb->info, 0);
module_put(fb->info->fbops->owner);
clear_bit(FBLOG_OPEN, &fb->flags);
+ fblog_buf_deinit(&fb->buf);
}
if (kill_dev)
@@ -379,6 +507,26 @@ static struct notifier_block fblog_notifier = {
.notifier_call = fblog_event,
};
+static void fblog_con_write(struct console *con, const char *buf,
+ unsigned int len)
+{
+ int i;
+
+ mutex_lock(&fblog_registration_lock);
+ for (i = 0; i < FB_MAX; ++i) {
+ if (fblog_fbs[i]) {
+ fblog_buf_write(&fblog_fbs[i]->buf, buf, len);
+ }
+ }
+ mutex_unlock(&fblog_registration_lock);
+}
+
+static struct console fblog_con_driver = {
+ .name = "fblog",
+ .write = fblog_con_write,
+ .flags = CON_PRINTBUFFER | CON_ENABLED,
+};
+
static int __init fblog_init(void)
{
int ret;
@@ -390,6 +538,7 @@ static int __init fblog_init(void)
}
fblog_scan();
+ register_console(&fblog_con_driver);
return 0;
}
@@ -399,6 +548,7 @@ static void __exit fblog_exit(void)
unsigned int i;
struct fb_info *info;
+ unregister_console(&fblog_con_driver);
fb_unregister_client(&fblog_notifier);
/* We scan through the whole registered_fb array here instead of
--
1.7.11.4
^ permalink raw reply related
* [PATCH 07/11] fblog: allow selecting fbs via sysfs and module-parameters
From: David Herrmann @ 2012-08-12 14:53 UTC (permalink / raw)
To: linux-fbdev
Cc: Florian Tobias Schandinat, Greg Kroah-Hartman, linux-serial,
Alan Cox, linux-kernel, Geert Uytterhoeven, David Herrmann
In-Reply-To: <1344783205-2384-1-git-send-email-dh.herrmann@googlemail.com>
fblog is mainly useful during boot, reboot, panics and maintenance. In all
cases you often want to control which monitors are used for console
output. Moreover, in multi-seat environments it is desireable to reduce
system-overhead by not drawing the console to all framebuffers. Four
mechanisms to select framebuffers for fblog are added:
1) "active" module parameter: This parameter selects whether fblog has
access to available framebuffer devices. If it is true, then fblog will
open devices following the rules described below and rendering will take
place. If it is false, new hotplugged devices will not be activated and no
more rendering to currently active devices takes place. However, active
devices will continue rendering after this is set to true again.
2) "active" sysfs attribute for each fblog object. Reading this value
returns whether a framebuffer is currently active. Writing it opens/closes
the framebuffer. This allows runtime control which fbs are used. For
instance, init can set these to 0 after bootup.
Note that a framebuffer is only active if this is 1 _and_ the "active"
module parameter is set to "true".
3) "activate_on_hotplug" module parameter: This selects whether a device
is activated by default when hotplugged. This is true by default so new
devices will be automatically activated.
4) "main_only" module parameter: This selects what devices are activated
on hotplug. This has no effect if "activate_on_hotplug" is false.
Otherwise, if this is true then only fb0 will be activated on hotplug.
This is false by default.
Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
---
drivers/video/console/fblog.c | 66 ++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 65 insertions(+), 1 deletion(-)
diff --git a/drivers/video/console/fblog.c b/drivers/video/console/fblog.c
index 1c526c5..aed77dc 100644
--- a/drivers/video/console/fblog.c
+++ b/drivers/video/console/fblog.c
@@ -44,6 +44,9 @@ struct fblog_fb {
static DEFINE_MUTEX(fblog_registration_lock);
static struct fblog_fb *fblog_fbs[FB_MAX];
+static bool active = true;
+static bool activate_on_hotplug = true;
+static bool main_only = false;
#define to_fblog_dev(_d) container_of(_d, struct fblog_fb, dev)
@@ -63,6 +66,9 @@ static int fblog_open(struct fblog_fb *fb)
{
int ret;
+ if (!active)
+ return -EPERM;
+
mutex_lock(&fb->lock);
if (test_bit(FBLOG_KILLED, &fb->flags)) {
@@ -115,6 +121,40 @@ static void fblog_close(struct fblog_fb *fb, bool kill_dev)
mutex_unlock(&fb->lock);
}
+static ssize_t fblog_dev_active_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct fblog_fb *fb = to_fblog_dev(dev);
+
+ return snprintf(buf, PAGE_SIZE, "%d\n",
+ !!test_bit(FBLOG_OPEN, &fb->flags));
+}
+
+static ssize_t fblog_dev_active_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t count)
+{
+ struct fblog_fb *fb = to_fblog_dev(dev);
+ unsigned long num;
+ int ret = 0;
+
+ num = simple_strtoul(buf, NULL, 10);
+
+ mutex_lock(&fb->info->lock);
+ if (num)
+ ret = fblog_open(fb);
+ else
+ fblog_close(fb, false);
+ mutex_unlock(&fb->info->lock);
+
+ return ret ? ret : count;
+}
+
+static DEVICE_ATTR(active, S_IRUGO | S_IWUSR | S_IWGRP, fblog_dev_active_show,
+ fblog_dev_active_store);
+
/*
* fblog framebuffer list
* The fblog_fbs[] array contains all currently registered framebuffers. If a
@@ -148,6 +188,7 @@ static void fblog_do_unregister(struct fb_info *info)
fblog_fbs[info->node] = NULL;
fblog_close(fb, true);
+ device_remove_file(&fb->dev, &dev_attr_active);
device_del(&fb->dev);
put_device(&fb->dev);
}
@@ -156,6 +197,7 @@ static void fblog_do_register(struct fb_info *info, bool force)
{
struct fblog_fb *fb;
int ret;
+ bool do_open = true;
fb = fblog_fbs[info->node];
if (fb && fb->info != info) {
@@ -186,7 +228,20 @@ static void fblog_do_register(struct fb_info *info, bool force)
return;
}
- fblog_open(fb);
+ ret = device_create_file(&fb->dev, &dev_attr_active);
+ if (ret) {
+ pr_err("fblog: cannot create sysfs entry");
+ /* do not open fb if we cannot create control file */
+ do_open = false;
+ }
+
+ if (!activate_on_hotplug)
+ do_open = false;
+ if (main_only && info->node != 0)
+ do_open = false;
+
+ if (do_open)
+ fblog_open(fb);
}
static void fblog_register(struct fb_info *info, bool force)
@@ -321,6 +376,15 @@ static void __exit fblog_exit(void)
}
}
+module_param(active, bool, S_IRUGO | S_IWUSR | S_IWGRP);
+MODULE_PARM_DESC(active, "Activate fblog rendering");
+
+module_param(activate_on_hotplug, bool, S_IRUGO | S_IWUSR | S_IWGRP);
+MODULE_PARM_DESC(activate_on_hotplug, "Activate fblog on hotplugged devices");
+
+module_param(main_only, bool, S_IRUGO);
+MODULE_PARM_DESC(main_only, "Activate fblog by default only on main devices");
+
module_init(fblog_init);
module_exit(fblog_exit);
MODULE_LICENSE("GPL");
--
1.7.11.4
^ permalink raw reply related
* [PATCH 06/11] fblog: open fb on registration
From: David Herrmann @ 2012-08-12 14:53 UTC (permalink / raw)
To: linux-fbdev
Cc: Florian Tobias Schandinat, Greg Kroah-Hartman, linux-serial,
Alan Cox, linux-kernel, Geert Uytterhoeven, David Herrmann
In-Reply-To: <1344783205-2384-1-git-send-email-dh.herrmann@googlemail.com>
This opens the framebuffer upon registration so we can use it for
drawing-operations. On unregistration we close it again.
While opening/closing or accessing the fb in any other way, we must hold
the fb-mutex. However, since the notifiers are often called with the mutex
already held, we cannot lock it _after_ taking the
fblog_registration_lock. Therefore, we require the caller to make sure the
fb-mutex is held.
Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
---
drivers/video/console/fblog.c | 94 ++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 93 insertions(+), 1 deletion(-)
diff --git a/drivers/video/console/fblog.c b/drivers/video/console/fblog.c
index 279f4d8..1c526c5 100644
--- a/drivers/video/console/fblog.c
+++ b/drivers/video/console/fblog.c
@@ -32,12 +32,14 @@
enum fblog_flags {
FBLOG_KILLED,
+ FBLOG_OPEN,
};
struct fblog_fb {
unsigned long flags;
struct fb_info *info;
struct device dev;
+ struct mutex lock;
};
static DEFINE_MUTEX(fblog_registration_lock);
@@ -46,6 +48,74 @@ static struct fblog_fb *fblog_fbs[FB_MAX];
#define to_fblog_dev(_d) container_of(_d, struct fblog_fb, dev)
/*
+ * fblog_open/close()
+ * These functions manage access to the underlying framebuffer. While opened, we
+ * have a valid reference to the fb and can use it for drawing operations. When
+ * the fb is unregistered, we drop our reference and close the fb so it can get
+ * deleted properly. We also mark it as dead so no further fblog_open() call
+ * will succeed.
+ * Both functions must be called with the fb->info->lock mutex held! But make
+ * sure to lock it _before_ locking the fblog-registration-lock. Otherwise, we
+ * will dead-lock with fb-registration.
+ */
+
+static int fblog_open(struct fblog_fb *fb)
+{
+ int ret;
+
+ mutex_lock(&fb->lock);
+
+ if (test_bit(FBLOG_KILLED, &fb->flags)) {
+ ret = -ENODEV;
+ goto unlock;
+ }
+
+ if (test_bit(FBLOG_OPEN, &fb->flags)) {
+ ret = 0;
+ goto unlock;
+ }
+
+ if (!try_module_get(fb->info->fbops->owner)) {
+ ret = -ENODEV;
+ goto out_killed;
+ }
+
+ if (fb->info->fbops->fb_open && fb->info->fbops->fb_open(fb->info, 0)) {
+ ret = -EIO;
+ goto out_unref;
+ }
+
+ set_bit(FBLOG_OPEN, &fb->flags);
+ mutex_unlock(&fb->lock);
+ return 0;
+
+out_unref:
+ module_put(fb->info->fbops->owner);
+out_killed:
+ set_bit(FBLOG_KILLED, &fb->flags);
+unlock:
+ mutex_unlock(&fb->lock);
+ return ret;
+}
+
+static void fblog_close(struct fblog_fb *fb, bool kill_dev)
+{
+ mutex_lock(&fb->lock);
+
+ if (test_bit(FBLOG_OPEN, &fb->flags)) {
+ if (fb->info->fbops->fb_release)
+ fb->info->fbops->fb_release(fb->info, 0);
+ module_put(fb->info->fbops->owner);
+ clear_bit(FBLOG_OPEN, &fb->flags);
+ }
+
+ if (kill_dev)
+ set_bit(FBLOG_KILLED, &fb->flags);
+
+ mutex_unlock(&fb->lock);
+}
+
+/*
* fblog framebuffer list
* The fblog_fbs[] array contains all currently registered framebuffers. If a
* framebuffer is in that list, we always must make sure that we own a reference
@@ -77,6 +147,7 @@ static void fblog_do_unregister(struct fb_info *info)
fblog_fbs[info->node] = NULL;
+ fblog_close(fb, true);
device_del(&fb->dev);
put_device(&fb->dev);
}
@@ -99,6 +170,7 @@ static void fblog_do_register(struct fb_info *info, bool force)
return;
fb->info = info;
+ mutex_init(&fb->lock);
__module_get(THIS_MODULE);
device_initialize(&fb->dev);
fb->dev.class = fb_class;
@@ -113,6 +185,8 @@ static void fblog_do_register(struct fb_info *info, bool force)
put_device(&fb->dev);
return;
}
+
+ fblog_open(fb);
}
static void fblog_register(struct fb_info *info, bool force)
@@ -134,6 +208,7 @@ static int fblog_event(struct notifier_block *self, unsigned long action,
{
struct fb_event *event = data;
struct fb_info *info = event->info;
+ struct fblog_fb *fb;
switch(action) {
case FB_EVENT_FB_REGISTERED:
@@ -145,8 +220,21 @@ static int fblog_event(struct notifier_block *self, unsigned long action,
case FB_EVENT_FB_UNREGISTERED:
/* This is called when a low-level system driver unregisters a
* framebuffer. The registration lock is held but the console
- * lock might not be held. */
+ * lock might not be held. The fb-lock is not held, either! */
+ mutex_lock(&info->lock);
fblog_unregister(info);
+ mutex_unlock(&info->lock);
+ break;
+ case FB_EVENT_FB_UNBIND:
+ /* Called directly before unregistering an FB. The FB is still
+ * valid here and the registration lock is held but the console
+ * lock might not be held (really?). */
+ mutex_lock(&fblog_registration_lock);
+ fb = fblog_fbs[info->node];
+ mutex_unlock(&fblog_registration_lock);
+
+ if (fb)
+ fblog_close(fb, true);
break;
}
@@ -163,7 +251,9 @@ static void fblog_scan(void)
if (!info || IS_ERR(info))
continue;
+ mutex_lock(&info->lock);
fblog_register(info, false);
+ mutex_unlock(&info->lock);
/* There is a very subtle race-condition. Even though we might
* own a reference to the fb, it may still get unregistered
@@ -224,7 +314,9 @@ static void __exit fblog_exit(void)
if (!info || IS_ERR(info))
continue;
+ mutex_lock(&info->lock);
fblog_unregister(info);
+ mutex_unlock(&info->lock);
put_fb_info(info);
}
}
--
1.7.11.4
^ permalink raw reply related
* [PATCH 05/11] fblog: register one fblog object per framebuffer
From: David Herrmann @ 2012-08-12 14:53 UTC (permalink / raw)
To: linux-fbdev
Cc: Florian Tobias Schandinat, Greg Kroah-Hartman, linux-serial,
Alan Cox, linux-kernel, Geert Uytterhoeven, David Herrmann
In-Reply-To: <1344783205-2384-1-git-send-email-dh.herrmann@googlemail.com>
One fblog object is associated to each registered framebuffer. This way,
we can draw the console to each framebuffer. When a framebuffer driver
unregisters a framebuffer, we also unregister our fblog object. That is,
our lifetime is coupled to the lifetime of the framebuffer. However, this
does not mean that we are always active. On the contrary, we do not even
own a reference to the framebuffer. We don't need it as we are notified
_before_ the last reference is dropped.
However, if other users have a reference to our object, we simply mark it
as dead when the associated framebuffer dies and leave it alone. When the
last reference is dropped, it will be automatically freed.
Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
---
drivers/video/console/fblog.c | 195 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 195 insertions(+)
diff --git a/drivers/video/console/fblog.c b/drivers/video/console/fblog.c
index fb39737..279f4d8 100644
--- a/drivers/video/console/fblog.c
+++ b/drivers/video/console/fblog.c
@@ -23,15 +23,210 @@
* all fblog instances before running other graphics applications.
*/
+#define pr_fmt(_fmt) KBUILD_MODNAME ": " _fmt
+
+#include <linux/device.h>
+#include <linux/fb.h>
#include <linux/module.h>
+#include <linux/mutex.h>
+
+enum fblog_flags {
+ FBLOG_KILLED,
+};
+
+struct fblog_fb {
+ unsigned long flags;
+ struct fb_info *info;
+ struct device dev;
+};
+
+static DEFINE_MUTEX(fblog_registration_lock);
+static struct fblog_fb *fblog_fbs[FB_MAX];
+
+#define to_fblog_dev(_d) container_of(_d, struct fblog_fb, dev)
+
+/*
+ * fblog framebuffer list
+ * The fblog_fbs[] array contains all currently registered framebuffers. If a
+ * framebuffer is in that list, we always must make sure that we own a reference
+ * to it. If it is added through the notifier callbacks, then this is always
+ * guaranteed.
+ * We are only interested in registered framebuffers. That is, if a driver calls
+ * unregister_framebuffer() we directly unlink it from our list. This guarantees
+ * that the associated fb_info is always valid. However, we might still have
+ * pending users so we mark it as dead so no further framebuffer actions are
+ * done. If the last user then drops a reference, the memory gets freed
+ * automatically.
+ */
+
+static void fblog_release(struct device *dev)
+{
+ struct fblog_fb *fb = to_fblog_dev(dev);
+
+ kfree(fb);
+ module_put(THIS_MODULE);
+}
+
+static void fblog_do_unregister(struct fb_info *info)
+{
+ struct fblog_fb *fb;
+
+ fb = fblog_fbs[info->node];
+ if (!fb || fb->info != info)
+ return;
+
+ fblog_fbs[info->node] = NULL;
+
+ device_del(&fb->dev);
+ put_device(&fb->dev);
+}
+
+static void fblog_do_register(struct fb_info *info, bool force)
+{
+ struct fblog_fb *fb;
+ int ret;
+
+ fb = fblog_fbs[info->node];
+ if (fb && fb->info != info) {
+ if (!force)
+ return;
+
+ fblog_do_unregister(fb->info);
+ }
+
+ fb = kzalloc(sizeof(*fb), GFP_KERNEL);
+ if (!fb)
+ return;
+
+ fb->info = info;
+ __module_get(THIS_MODULE);
+ device_initialize(&fb->dev);
+ fb->dev.class = fb_class;
+ fb->dev.release = fblog_release;
+ dev_set_name(&fb->dev, "fblog%d", info->node);
+ fblog_fbs[info->node] = fb;
+
+ ret = device_add(&fb->dev);
+ if (ret) {
+ fblog_fbs[info->node] = NULL;
+ set_bit(FBLOG_KILLED, &fb->flags);
+ put_device(&fb->dev);
+ return;
+ }
+}
+
+static void fblog_register(struct fb_info *info, bool force)
+{
+ mutex_lock(&fblog_registration_lock);
+ fblog_do_register(info, force);
+ mutex_unlock(&fblog_registration_lock);
+}
+
+static void fblog_unregister(struct fb_info *info)
+{
+ mutex_lock(&fblog_registration_lock);
+ fblog_do_unregister(info);
+ mutex_unlock(&fblog_registration_lock);
+}
+
+static int fblog_event(struct notifier_block *self, unsigned long action,
+ void *data)
+{
+ struct fb_event *event = data;
+ struct fb_info *info = event->info;
+
+ switch(action) {
+ case FB_EVENT_FB_REGISTERED:
+ /* This is called when a low-level system driver registers a new
+ * framebuffer. The registration lock is held but the console
+ * lock might not be held when this is called. */
+ fblog_register(info, true);
+ break;
+ case FB_EVENT_FB_UNREGISTERED:
+ /* This is called when a low-level system driver unregisters a
+ * framebuffer. The registration lock is held but the console
+ * lock might not be held. */
+ fblog_unregister(info);
+ break;
+ }
+
+ return 0;
+}
+
+static void fblog_scan(void)
+{
+ unsigned int i;
+ struct fb_info *info, *tmp;
+
+ for (i = 0; i < FB_MAX; ++i) {
+ info = get_fb_info(i);
+ if (!info || IS_ERR(info))
+ continue;
+
+ fblog_register(info, false);
+
+ /* There is a very subtle race-condition. Even though we might
+ * own a reference to the fb, it may still get unregistered
+ * between our call from get_fb_info() and fblog_register().
+ * Therefore, we simply check whether the same fb still is
+ * registered by calling get_fb_info() again. Only if they
+ * differ we know that it got unregistered, therefore, we
+ * call fblog_unregister() with the old pointer. */
+
+ tmp = get_fb_info(i);
+ if (tmp && !IS_ERR(tmp))
+ put_fb_info(tmp);
+ if (tmp != info)
+ fblog_unregister(info);
+
+ /* Here we either called fblog_unregister() and therefore do not
+ * need any reference to the fb, or we can be sure that the FB
+ * is registered and FB_EVENT_FB_UNREGISTERED will be called
+ * before the last reference is dropped. Hence, we can drop our
+ * reference here. */
+
+ put_fb_info(info);
+ }
+}
+
+static struct notifier_block fblog_notifier = {
+ .notifier_call = fblog_event,
+};
static int __init fblog_init(void)
{
+ int ret;
+
+ ret = fb_register_client(&fblog_notifier);
+ if (ret) {
+ pr_err("cannot register framebuffer notifier\n");
+ return ret;
+ }
+
+ fblog_scan();
+
return 0;
}
static void __exit fblog_exit(void)
{
+ unsigned int i;
+ struct fb_info *info;
+
+ fb_unregister_client(&fblog_notifier);
+
+ /* We scan through the whole registered_fb array here instead of
+ * fblog_fbs because we need to get the device lock _before_ the
+ * fblog-registration-lock. */
+
+ for (i = 0; i < FB_MAX; ++i) {
+ info = get_fb_info(i);
+ if (!info || IS_ERR(info))
+ continue;
+
+ fblog_unregister(info);
+ put_fb_info(info);
+ }
}
module_init(fblog_init);
--
1.7.11.4
^ permalink raw reply related
* [PATCH 04/11] fbdev: export get_fb_info()/put_fb_info()
From: David Herrmann @ 2012-08-12 14:53 UTC (permalink / raw)
To: linux-fbdev
Cc: Florian Tobias Schandinat, Greg Kroah-Hartman, linux-serial,
Alan Cox, linux-kernel, Geert Uytterhoeven, David Herrmann
In-Reply-To: <1344783205-2384-1-git-send-email-dh.herrmann@googlemail.com>
When adding other internal users of the framebuffer subsystem, we need a
way to get references to framebuffers. These two functions already exist
so export them.
Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
---
drivers/video/fbmem.c | 6 ++++--
include/linux/fb.h | 3 +++
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
index 0dff12a..1312ba2 100644
--- a/drivers/video/fbmem.c
+++ b/drivers/video/fbmem.c
@@ -46,7 +46,7 @@ static DEFINE_MUTEX(registration_lock);
struct fb_info *registered_fb[FB_MAX] __read_mostly;
int num_registered_fb __read_mostly;
-static struct fb_info *get_fb_info(unsigned int idx)
+struct fb_info *get_fb_info(unsigned int idx)
{
struct fb_info *fb_info;
@@ -61,14 +61,16 @@ static struct fb_info *get_fb_info(unsigned int idx)
return fb_info;
}
+EXPORT_SYMBOL_GPL(get_fb_info);
-static void put_fb_info(struct fb_info *fb_info)
+void put_fb_info(struct fb_info *fb_info)
{
if (!atomic_dec_and_test(&fb_info->count))
return;
if (fb_info->fbops->fb_destroy)
fb_info->fbops->fb_destroy(fb_info);
}
+EXPORT_SYMBOL_GPL(put_fb_info);
int lock_fb_info(struct fb_info *info)
{
diff --git a/include/linux/fb.h b/include/linux/fb.h
index ac3f1c6..2d51c0e 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -1033,6 +1033,9 @@ static inline void unlock_fb_info(struct fb_info *info)
mutex_unlock(&info->lock);
}
+extern struct fb_info *get_fb_info(unsigned int idx);
+extern void put_fb_info(struct fb_info *fb_info);
+
static inline void __fb_pad_aligned_buffer(u8 *dst, u32 d_pitch,
u8 *src, u32 s_pitch, u32 height)
{
--
1.7.11.4
^ permalink raw reply related
* [PATCH 03/11] fblog: new framebuffer kernel log dummy driver
From: David Herrmann @ 2012-08-12 14:53 UTC (permalink / raw)
To: linux-fbdev
Cc: Florian Tobias Schandinat, Greg Kroah-Hartman, linux-serial,
Alan Cox, linux-kernel, Geert Uytterhoeven, David Herrmann
In-Reply-To: <1344783205-2384-1-git-send-email-dh.herrmann@googlemail.com>
Fblog displays all kernel log messages on all connected framebuffers. It
replaces fbcon when CONFIG_VT=n is selected. Its main purpose is to debug
boot problems by displaying the whole boot log on the screen. This patch
provides the first dummy module-init/deinit functions.
As it uses all the font and fb functions I placed it in
drivers/video/console. However, this means that we need to move the check
for CONFIG_VT in Makefile/Kconfig from drivers/video into
drivers/video/console as fblog does not depend on CONFIG_VT.
Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
---
drivers/video/Kconfig | 5 +----
drivers/video/Makefile | 2 +-
drivers/video/console/Kconfig | 37 +++++++++++++++++++++++++++++--------
drivers/video/console/Makefile | 1 +
drivers/video/console/fblog.c | 41 +++++++++++++++++++++++++++++++++++++++++
5 files changed, 73 insertions(+), 13 deletions(-)
create mode 100644 drivers/video/console/fblog.c
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 0217f74..e8fd53d 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -2448,10 +2448,7 @@ source "drivers/video/omap/Kconfig"
source "drivers/video/omap2/Kconfig"
source "drivers/video/exynos/Kconfig"
source "drivers/video/backlight/Kconfig"
-
-if VT
- source "drivers/video/console/Kconfig"
-endif
+source "drivers/video/console/Kconfig"
if FB || SGI_NEWPORT_CONSOLE
source "drivers/video/logo/Kconfig"
diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index ee8dafb..9f8a7f0 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -11,7 +11,7 @@ fb-y := fbmem.o fbmon.o fbcmap.o fbsysfs.o \
modedb.o fbcvt.o
fb-objs := $(fb-y)
-obj-$(CONFIG_VT) += console/
+obj-y += console/
obj-$(CONFIG_LOGO) += logo/
obj-y += backlight/
diff --git a/drivers/video/console/Kconfig b/drivers/video/console/Kconfig
index e2c96d0..7374362 100644
--- a/drivers/video/console/Kconfig
+++ b/drivers/video/console/Kconfig
@@ -6,7 +6,7 @@ menu "Console display driver support"
config VGA_CONSOLE
bool "VGA text console" if EXPERT || !X86
- depends on !4xx && !8xx && !SPARC && !M68K && !PARISC && !FRV && !SUPERH && !BLACKFIN && !AVR32 && !MN10300 && (!ARM || ARCH_FOOTBRIDGE || ARCH_INTEGRATOR || ARCH_NETWINDER)
+ depends on VT && !4xx && !8xx && !SPARC && !M68K && !PARISC && !FRV && !SUPERH && !BLACKFIN && !AVR32 && !MN10300 && (!ARM || ARCH_FOOTBRIDGE || ARCH_INTEGRATOR || ARCH_NETWINDER)
default y
help
Saying Y here will allow you to use Linux in text mode through a
@@ -45,7 +45,7 @@ config VGACON_SOFT_SCROLLBACK_SIZE
screenfuls of scrollback buffer
config MDA_CONSOLE
- depends on !M68K && !PARISC && ISA
+ depends on VT && !M68K && !PARISC && ISA
tristate "MDA text console (dual-headed) (EXPERIMENTAL)"
---help---
Say Y here if you have an old MDA or monochrome Hercules graphics
@@ -61,14 +61,14 @@ config MDA_CONSOLE
config SGI_NEWPORT_CONSOLE
tristate "SGI Newport Console support"
- depends on SGI_IP22
+ depends on VT && SGI_IP22
help
Say Y here if you want the console on the Newport aka XL graphics
card of your Indy. Most people say Y here.
config DUMMY_CONSOLE
bool
- depends on VGA_CONSOLE!=y || SGI_NEWPORT_CONSOLE!=y
+ depends on VT && (VGA_CONSOLE!=y || SGI_NEWPORT_CONSOLE!=y)
default y
config DUMMY_CONSOLE_COLUMNS
@@ -89,7 +89,7 @@ config DUMMY_CONSOLE_ROWS
config FRAMEBUFFER_CONSOLE
tristate "Framebuffer Console support"
- depends on FB
+ depends on VT && FB
select CRC32
help
Low-level framebuffer-based console driver.
@@ -122,16 +122,37 @@ config FRAMEBUFFER_CONSOLE_ROTATION
config STI_CONSOLE
bool "STI text console"
- depends on PARISC
+ depends on VT && PARISC
default y
help
The STI console is the builtin display/keyboard on HP-PARISC
machines. Say Y here to build support for it into your kernel.
The alternative is to use your primary serial port as a console.
+config FBLOG
+ tristate "Framebuffer Kernel Log Driver"
+ depends on !VT && FB
+ default n
+ help
+ This driver displays all kernel log messages on all connected
+ framebuffers. It is mutually exclusive with CONFIG_FRAMEBUFFER_CONSOLE
+ and CONFIG_VT. It was mainly created for debugging purposes when
+ CONFIG_VT is not selected but you still want kernel boot messages on
+ the screen.
+
+ This driver overwrites all other graphics output on the framebuffer as
+ long as it is active so the kernel log will always be visible. You
+ need to disable this driver via sysfs to be able to start another
+ graphics application.
+
+ If unsure, say N.
+
+ To compile this driver as a module, choose M here: the module will
+ be called fblog.
+
config FONTS
bool "Select compiled-in fonts"
- depends on FRAMEBUFFER_CONSOLE || STI_CONSOLE
+ depends on FRAMEBUFFER_CONSOLE || STI_CONSOLE || FBLOG
help
Say Y here if you would like to use fonts other than the default
your frame buffer console usually use.
@@ -158,7 +179,7 @@ config FONT_8x8
config FONT_8x16
bool "VGA 8x16 font" if FONTS
- depends on FRAMEBUFFER_CONSOLE || SGI_NEWPORT_CONSOLE || STI_CONSOLE || USB_SISUSBVGA_CON
+ depends on FRAMEBUFFER_CONSOLE || SGI_NEWPORT_CONSOLE || STI_CONSOLE || USB_SISUSBVGA_CON || FBLOG
default y if !SPARC && !FONTS
help
This is the "high resolution" font for the VGA frame buffer (the one
diff --git a/drivers/video/console/Makefile b/drivers/video/console/Makefile
index 9a52226..ec0e155 100644
--- a/drivers/video/console/Makefile
+++ b/drivers/video/console/Makefile
@@ -20,6 +20,7 @@ font-objs += $(font-objs-y)
# Each configuration option enables a list of files.
+obj-$(CONFIG_FBLOG) += fblog.o font.o fbdraw.o
obj-$(CONFIG_DUMMY_CONSOLE) += dummycon.o
obj-$(CONFIG_SGI_NEWPORT_CONSOLE) += newport_con.o font.o
obj-$(CONFIG_STI_CONSOLE) += sticon.o sticore.o font.o
diff --git a/drivers/video/console/fblog.c b/drivers/video/console/fblog.c
new file mode 100644
index 0000000..fb39737
--- /dev/null
+++ b/drivers/video/console/fblog.c
@@ -0,0 +1,41 @@
+/*
+ * Framebuffer Kernel Log Driver
+ * Copyright (c) 2012 David Herrmann <dh.herrmann@googlemail.com>
+ */
+
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ */
+
+/*
+ * Framebuffer Kernel Log
+ * This driver prints the kernel log to all connected display devices. It
+ * replaces CONFIG_VT and cannot run simultaneously with it. It does not provide
+ * any virtual-terminal, though. It should only be used to get kernel boot
+ * messages to debug kernel errors.
+ * Hence, this driver is neither optimized for speed, nor does it provide any
+ * fancy features like colored text output.
+ * This driver forcibly writes to the framebuffer while active, therefore, you
+ * cannot run other graphics applications simultaneously. You need to disable
+ * all fblog instances before running other graphics applications.
+ */
+
+#include <linux/module.h>
+
+static int __init fblog_init(void)
+{
+ return 0;
+}
+
+static void __exit fblog_exit(void)
+{
+}
+
+module_init(fblog_init);
+module_exit(fblog_exit);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Herrmann <dh.herrmann@googlemail.com>");
+MODULE_DESCRIPTION("Framebuffer Kernel Log Driver");
--
1.7.11.4
^ permalink raw reply related
* [PATCH 02/11] fbcon: move bit_putcs() into separate source file
From: David Herrmann @ 2012-08-12 14:53 UTC (permalink / raw)
To: linux-fbdev
Cc: Florian Tobias Schandinat, Greg Kroah-Hartman, linux-serial,
Alan Cox, linux-kernel, Geert Uytterhoeven, David Herrmann
In-Reply-To: <1344783205-2384-1-git-send-email-dh.herrmann@googlemail.com>
If we want to use font-draw-operations in other modules than fbcon, we
need to split this function off of fbcon headers and sources. This also
makes bit_putcs() totally independent of vc_* and fbcon_* structures.
As scr_read() cannot be called inside of non-fbcon/vt functions, we need
to assemble the buffer before passing it to fbdraw_font(). This slows down
this operations a little bit but my rough benchmark showed that it didn't
really matter. Anyway, if it does, we can still put it into VT_BUF_HAVE_RW
conditions so platforms that don't use it won't be affected. And for other
platforms we can add the buffer to the vc-struct so we can reuse it.
Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
---
drivers/video/console/bitblit.c | 127 ++++------------------------------------
drivers/video/console/fbdraw.c | 125 +++++++++++++++++++++++++++++++++++++++
drivers/video/console/fbdraw.h | 4 ++
3 files changed, 139 insertions(+), 117 deletions(-)
diff --git a/drivers/video/console/bitblit.c b/drivers/video/console/bitblit.c
index 6ec2905..c5d897b 100644
--- a/drivers/video/console/bitblit.c
+++ b/drivers/video/console/bitblit.c
@@ -54,132 +54,25 @@ static void bit_clear(struct vc_data *vc, struct fb_info *info, int sy,
info->fbops->fb_fillrect(info, ®ion);
}
-static inline void bit_putcs_aligned(struct vc_data *vc, struct fb_info *info,
- const u16 *s, u32 attr, u32 cnt,
- u32 d_pitch, u32 s_pitch, u32 cellsize,
- struct fb_image *image, u8 *buf, u8 *dst)
-{
- u16 charmask = vc->vc_hi_font_mask ? 0x1ff : 0xff;
- u32 idx = vc->vc_font.width >> 3;
- u8 *src;
-
- while (cnt--) {
- src = vc->vc_font.data + (scr_readw(s++)&
- charmask)*cellsize;
-
- if (attr) {
- fbdraw_update_attr(buf, src, attr, &vc->vc_font);
- src = buf;
- }
-
- if (likely(idx == 1))
- __fb_pad_aligned_buffer(dst, d_pitch, src, idx,
- image->height);
- else
- fb_pad_aligned_buffer(dst, d_pitch, src, idx,
- image->height);
-
- dst += s_pitch;
- }
-
- info->fbops->fb_imageblit(info, image);
-}
-
-static inline void bit_putcs_unaligned(struct vc_data *vc,
- struct fb_info *info, const u16 *s,
- u32 attr, u32 cnt, u32 d_pitch,
- u32 s_pitch, u32 cellsize,
- struct fb_image *image, u8 *buf,
- u8 *dst)
-{
- u16 charmask = vc->vc_hi_font_mask ? 0x1ff : 0xff;
- u32 shift_low = 0, mod = vc->vc_font.width % 8;
- u32 shift_high = 8;
- u32 idx = vc->vc_font.width >> 3;
- u8 *src;
-
- while (cnt--) {
- src = vc->vc_font.data + (scr_readw(s++)&
- charmask)*cellsize;
-
- if (attr) {
- fbdraw_update_attr(buf, src, attr, &vc->vc_font);
- src = buf;
- }
-
- fb_pad_unaligned_buffer(dst, d_pitch, src, idx,
- image->height, shift_high,
- shift_low, mod);
- shift_low += mod;
- dst += (shift_low >= 8) ? s_pitch : s_pitch - 1;
- shift_low &= 7;
- shift_high = 8 - shift_low;
- }
-
- info->fbops->fb_imageblit(info, image);
-
-}
-
static void bit_putcs(struct vc_data *vc, struct fb_info *info,
const unsigned short *s, int count, int yy, int xx,
int fg, int bg)
{
- struct fb_image image;
- u32 width = DIV_ROUND_UP(vc->vc_font.width, 8);
- u32 cellsize = width * vc->vc_font.height;
- u32 maxcnt = info->pixmap.size/cellsize;
- u32 scan_align = info->pixmap.scan_align - 1;
- u32 buf_align = info->pixmap.buf_align - 1;
- u32 mod = vc->vc_font.width % 8, cnt, pitch, size;
+ u16 *buf;
+ int i;
u32 attribute = get_attribute(info, scr_readw(s));
- u8 *dst, *buf = NULL;
- image.fg_color = fg;
- image.bg_color = bg;
- image.dx = xx * vc->vc_font.width;
- image.dy = yy * vc->vc_font.height;
- image.height = vc->vc_font.height;
- image.depth = 1;
+ buf = kmalloc(sizeof(*buf) * count, GFP_KERNEL);
+ if (!buf)
+ return;
- if (attribute) {
- buf = kmalloc(cellsize, GFP_KERNEL);
- if (!buf)
- return;
- }
-
- while (count) {
- if (count > maxcnt)
- cnt = maxcnt;
- else
- cnt = count;
-
- image.width = vc->vc_font.width * cnt;
- pitch = DIV_ROUND_UP(image.width, 8) + scan_align;
- pitch &= ~scan_align;
- size = pitch * image.height + buf_align;
- size &= ~buf_align;
- dst = fb_get_buffer_offset(info, &info->pixmap, size);
- image.data = dst;
-
- if (!mod)
- bit_putcs_aligned(vc, info, s, attribute, cnt, pitch,
- width, cellsize, &image, buf, dst);
- else
- bit_putcs_unaligned(vc, info, s, attribute, cnt,
- pitch, width, cellsize, &image,
- buf, dst);
-
- image.dx += cnt * vc->vc_font.width;
- count -= cnt;
- s += cnt;
- }
+ for (i = 0; i < count; ++i)
+ buf[i] = scr_readw(s++);
- /* buf is always NULL except when in monochrome mode, so in this case
- it's a gain to check buf against NULL even though kfree() handles
- NULL pointers just fine */
- if (unlikely(buf))
- kfree(buf);
+ fbdraw_font(info, &vc->vc_font, vc->vc_hi_font_mask, xx, yy, fg, bg,
+ attribute, buf, count);
+ kfree(buf);
}
static void bit_clear_margins(struct vc_data *vc, struct fb_info *info,
diff --git a/drivers/video/console/fbdraw.c b/drivers/video/console/fbdraw.c
index aa18f7e..f7c3da7 100644
--- a/drivers/video/console/fbdraw.c
+++ b/drivers/video/console/fbdraw.c
@@ -41,6 +41,131 @@ void fbdraw_update_attr(u8 *dst, const u8 *src, int attribute,
}
EXPORT_SYMBOL_GPL(fbdraw_update_attr);
+static inline void bit_putcs_aligned(struct fb_info *info, bool hi_font,
+ struct console_font *font, u32 attribute,
+ u32 d_pitch, u32 s_pitch, u32 cellsize,
+ struct fb_image *image, u8 *buf, u8 *dst,
+ const u16 *chars, size_t cnt)
+{
+ u16 charmask = hi_font ? 0x1ff : 0xff;
+ u32 idx = font->width >> 3;
+ u8 *src;
+
+ while (cnt--) {
+ src = font->data + ((*chars++) & charmask) * cellsize;
+
+ if (attribute) {
+ fbdraw_update_attr(buf, src, attribute, font);
+ src = buf;
+ }
+
+ if (likely(idx == 1))
+ __fb_pad_aligned_buffer(dst, d_pitch, src, idx,
+ image->height);
+ else
+ fb_pad_aligned_buffer(dst, d_pitch, src, idx,
+ image->height);
+
+ dst += s_pitch;
+ }
+
+ info->fbops->fb_imageblit(info, image);
+}
+
+static inline void bit_putcs_unaligned(struct fb_info *info, bool hi_font,
+ struct console_font *font, u32 attribute,
+ u32 d_pitch, u32 s_pitch, u32 cellsize,
+ struct fb_image *image, u8 *buf, u8 *dst,
+ const u16 *chars, size_t cnt)
+{
+ u16 charmask = hi_font ? 0x1ff : 0xff;
+ u32 shift_low = 0, mod = font->width % 8;
+ u32 shift_high = 8;
+ u32 idx = font->width >> 3;
+ u8 *src;
+
+ while (cnt--) {
+ src = font->data + ((*chars++) & charmask) * cellsize;
+
+ if (attribute) {
+ fbdraw_update_attr(buf, src, attribute, font);
+ src = buf;
+ }
+
+ fb_pad_unaligned_buffer(dst, d_pitch, src, idx,
+ image->height, shift_high,
+ shift_low, mod);
+ shift_low += mod;
+ dst += (shift_low >= 8) ? s_pitch : s_pitch - 1;
+ shift_low &= 7;
+ shift_high = 8 - shift_low;
+ }
+
+ info->fbops->fb_imageblit(info, image);
+}
+
+void fbdraw_font(struct fb_info *info, struct console_font *font, bool hi_font,
+ unsigned int xpos, unsigned int ypos, int fg, int bg,
+ u32 attribute, const u16 *chars, size_t count)
+{
+ struct fb_image image;
+ u32 width = DIV_ROUND_UP(font->width, 8);
+ u32 cellsize = width * font->height;
+ u32 maxcnt = info->pixmap.size / cellsize;
+ u32 scan_align = info->pixmap.scan_align - 1;
+ u32 buf_align = info->pixmap.buf_align - 1;
+ u32 mod = font->width % 8, cnt, pitch, size;
+ u8 *dst, *buf = NULL;
+
+ image.fg_color = fg;
+ image.bg_color = bg;
+ image.dx = xpos * font->width;
+ image.dy = ypos * font->height;
+ image.height = font->height;
+ image.depth = 1;
+
+ if (attribute) {
+ buf = kmalloc(cellsize, GFP_KERNEL);
+ if (!buf)
+ return;
+ }
+
+ while (count) {
+ if (count > maxcnt)
+ cnt = maxcnt;
+ else
+ cnt = count;
+
+ image.width = font->width * cnt;
+ pitch = DIV_ROUND_UP(image.width, 8) + scan_align;
+ pitch &= ~scan_align;
+ size = pitch * image.height + buf_align;
+ size &= ~buf_align;
+ dst = fb_get_buffer_offset(info, &info->pixmap, size);
+ image.data = dst;
+
+ if (!mod)
+ bit_putcs_aligned(info, hi_font, font, attribute,
+ pitch, width, cellsize, &image, buf,
+ dst, chars, cnt);
+ else
+ bit_putcs_unaligned(info, hi_font, font, attribute,
+ pitch, width, cellsize, &image, buf,
+ dst, chars, cnt);
+
+ image.dx += cnt * font->width;
+ count -= cnt;
+ chars += cnt;
+ }
+
+ /* buf is always NULL except when in monochrome mode, so in this case
+ it's a gain to check buf against NULL even though kfree() handles
+ NULL pointers just fine */
+ if (unlikely(buf))
+ kfree(buf);
+}
+EXPORT_SYMBOL_GPL(fbdraw_font);
+
MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Herrmann <dh.herrmann@googlemail.com>");
MODULE_DESCRIPTION("Framebuffer helpers for image draw-operations");
diff --git a/drivers/video/console/fbdraw.h b/drivers/video/console/fbdraw.h
index 77edd7f..b9f1ffa 100644
--- a/drivers/video/console/fbdraw.h
+++ b/drivers/video/console/fbdraw.h
@@ -23,4 +23,8 @@
void fbdraw_update_attr(u8 *dst, const u8 *src, int attribute,
struct console_font *font);
+void fbdraw_font(struct fb_info *info, struct console_font *font, bool hi_font,
+ unsigned int xpos, unsigned int ypos, int fg, int bg,
+ u32 attribute, const u16 *chars, size_t count);
+
#endif /* _VIDEO_FBDRAW_H */
--
1.7.11.4
^ permalink raw reply related
* [PATCH 01/11] fbcon: move update_attr() into separate source file
From: David Herrmann @ 2012-08-12 14:53 UTC (permalink / raw)
To: linux-fbdev
Cc: Florian Tobias Schandinat, Greg Kroah-Hartman, linux-serial,
Alan Cox, linux-kernel, Geert Uytterhoeven, David Herrmann
In-Reply-To: <1344783205-2384-1-git-send-email-dh.herrmann@googlemail.com>
If we want to use update_attr() independently from fbcon, we need to split
it off from bitblit.c and fbcon.h. Therefore, introduce a new header and
source file (fbdraw.[ch]) which does not depende on vc_* and fbcon_*
structures in any way.
This does not introduce any new code nor does it make the paths deeper,
it simply splits the function off.
The other update_attr() functions (inside the rotation sources) seem
similar but are significantly different and I haven't found a way to merge
them efficiently (which is probably the reason why they are split off
now). Furthermore, I do not intend to use them in the coming code so there
is no need to split them off.
Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
---
drivers/video/console/Makefile | 3 ++-
drivers/video/console/bitblit.c | 26 +++--------------------
drivers/video/console/fbcon.h | 5 +----
drivers/video/console/fbdraw.c | 46 +++++++++++++++++++++++++++++++++++++++++
drivers/video/console/fbdraw.h | 26 +++++++++++++++++++++++
5 files changed, 78 insertions(+), 28 deletions(-)
create mode 100644 drivers/video/console/fbdraw.c
create mode 100644 drivers/video/console/fbdraw.h
diff --git a/drivers/video/console/Makefile b/drivers/video/console/Makefile
index a862e91..9a52226 100644
--- a/drivers/video/console/Makefile
+++ b/drivers/video/console/Makefile
@@ -25,7 +25,8 @@ obj-$(CONFIG_SGI_NEWPORT_CONSOLE) += newport_con.o font.o
obj-$(CONFIG_STI_CONSOLE) += sticon.o sticore.o font.o
obj-$(CONFIG_VGA_CONSOLE) += vgacon.o
obj-$(CONFIG_MDA_CONSOLE) += mdacon.o
-obj-$(CONFIG_FRAMEBUFFER_CONSOLE) += fbcon.o bitblit.o font.o softcursor.o
+obj-$(CONFIG_FRAMEBUFFER_CONSOLE) += fbcon.o bitblit.o font.o softcursor.o \
+ fbdraw.o
ifeq ($(CONFIG_FB_TILEBLITTING),y)
obj-$(CONFIG_FRAMEBUFFER_CONSOLE) += tileblit.o
endif
diff --git a/drivers/video/console/bitblit.c b/drivers/video/console/bitblit.c
index 28b1a83..6ec2905 100644
--- a/drivers/video/console/bitblit.c
+++ b/drivers/video/console/bitblit.c
@@ -22,26 +22,6 @@
/*
* Accelerated handlers.
*/
-static void update_attr(u8 *dst, u8 *src, int attribute,
- struct vc_data *vc)
-{
- int i, offset = (vc->vc_font.height < 10) ? 1 : 2;
- int width = DIV_ROUND_UP(vc->vc_font.width, 8);
- unsigned int cellsize = vc->vc_font.height * width;
- u8 c;
-
- offset = cellsize - (offset * width);
- for (i = 0; i < cellsize; i++) {
- c = src[i];
- if (attribute & FBCON_ATTRIBUTE_UNDERLINE && i >= offset)
- c = 0xff;
- if (attribute & FBCON_ATTRIBUTE_BOLD)
- c |= c >> 1;
- if (attribute & FBCON_ATTRIBUTE_REVERSE)
- c = ~c;
- dst[i] = c;
- }
-}
static void bit_bmove(struct vc_data *vc, struct fb_info *info, int sy,
int sx, int dy, int dx, int height, int width)
@@ -88,7 +68,7 @@ static inline void bit_putcs_aligned(struct vc_data *vc, struct fb_info *info,
charmask)*cellsize;
if (attr) {
- update_attr(buf, src, attr, vc);
+ fbdraw_update_attr(buf, src, attr, &vc->vc_font);
src = buf;
}
@@ -123,7 +103,7 @@ static inline void bit_putcs_unaligned(struct vc_data *vc,
charmask)*cellsize;
if (attr) {
- update_attr(buf, src, attr, vc);
+ fbdraw_update_attr(buf, src, attr, &vc->vc_font);
src = buf;
}
@@ -275,7 +255,7 @@ static void bit_cursor(struct vc_data *vc, struct fb_info *info, int mode,
return;
kfree(ops->cursor_data);
ops->cursor_data = dst;
- update_attr(dst, src, attribute, vc);
+ fbdraw_update_attr(dst, src, attribute, &vc->vc_font);
src = dst;
}
diff --git a/drivers/video/console/fbcon.h b/drivers/video/console/fbcon.h
index 6bd2e0c..8623bac 100644
--- a/drivers/video/console/fbcon.h
+++ b/drivers/video/console/fbcon.h
@@ -16,6 +16,7 @@
#include <linux/vt_kern.h>
#include <asm/io.h>
+#include "fbdraw.h"
#define FBCON_FLAGS_INIT 1
#define FBCON_FLAGS_CURSOR_TIMER 2
@@ -219,10 +220,6 @@ extern void fbcon_set_tileops(struct vc_data *vc, struct fb_info *info);
extern void fbcon_set_bitops(struct fbcon_ops *ops);
extern int soft_cursor(struct fb_info *info, struct fb_cursor *cursor);
-#define FBCON_ATTRIBUTE_UNDERLINE 1
-#define FBCON_ATTRIBUTE_REVERSE 2
-#define FBCON_ATTRIBUTE_BOLD 4
-
static inline int real_y(struct display *p, int ypos)
{
int rows = p->vrows;
diff --git a/drivers/video/console/fbdraw.c b/drivers/video/console/fbdraw.c
new file mode 100644
index 0000000..aa18f7e
--- /dev/null
+++ b/drivers/video/console/fbdraw.c
@@ -0,0 +1,46 @@
+/*
+ * Framebuffer helpers for image draw-operations
+ *
+ * Copyright (c) 2004 Antonino Daplas <adaplas @pol.net>
+ * Copyright (c) 2012 David Herrmann <dh.herrmann@googlemail.com>
+ *
+ * Originally from drivers/video/console/bitblit.c which itself originally is
+ * from the 'accel_*' routines in drivers/video/console/fbcon.c.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file COPYING in the main directory of this archive for
+ * more details.
+ */
+
+#include <linux/console.h>
+#include <linux/fb.h>
+#include <linux/kd.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include "fbdraw.h"
+
+void fbdraw_update_attr(u8 *dst, const u8 *src, int attribute,
+ struct console_font *font)
+{
+ int i, offset = (font->height < 10) ? 1 : 2;
+ int width = DIV_ROUND_UP(font->width, 8);
+ unsigned int cellsize = font->height * width;
+ u8 c;
+
+ offset = cellsize - (offset * width);
+ for (i = 0; i < cellsize; i++) {
+ c = src[i];
+ if (attribute & FBCON_ATTRIBUTE_UNDERLINE && i >= offset)
+ c = 0xff;
+ if (attribute & FBCON_ATTRIBUTE_BOLD)
+ c |= c >> 1;
+ if (attribute & FBCON_ATTRIBUTE_REVERSE)
+ c = ~c;
+ dst[i] = c;
+ }
+}
+EXPORT_SYMBOL_GPL(fbdraw_update_attr);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Herrmann <dh.herrmann@googlemail.com>");
+MODULE_DESCRIPTION("Framebuffer helpers for image draw-operations");
diff --git a/drivers/video/console/fbdraw.h b/drivers/video/console/fbdraw.h
new file mode 100644
index 0000000..77edd7f
--- /dev/null
+++ b/drivers/video/console/fbdraw.h
@@ -0,0 +1,26 @@
+/*
+ * Framebuffer helpers for image draw-operations
+ *
+ * Copyright (c) 2012 David Herrmann <dh.herrmann@googlemail.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file COPYING in the main directory of this archive for
+ * more details.
+ */
+
+#ifndef _VIDEO_FBDRAW_H
+#define _VIDEO_FBDRAW_H
+
+#include <linux/console.h>
+#include <linux/fb.h>
+#include <linux/kd.h>
+
+/* fbcon character attributes */
+#define FBCON_ATTRIBUTE_UNDERLINE 1
+#define FBCON_ATTRIBUTE_REVERSE 2
+#define FBCON_ATTRIBUTE_BOLD 4
+
+void fbdraw_update_attr(u8 *dst, const u8 *src, int attribute,
+ struct console_font *font);
+
+#endif /* _VIDEO_FBDRAW_H */
--
1.7.11.4
^ permalink raw reply related
* [PATCH 00/11] fblog: Framebuffer kernel log driver v4
From: David Herrmann @ 2012-08-12 14:53 UTC (permalink / raw)
To: linux-fbdev
Cc: Florian Tobias Schandinat, Greg Kroah-Hartman, linux-serial,
Alan Cox, linux-kernel, Geert Uytterhoeven, David Herrmann
Hi
This is revision 4 of the fblog driver. It is a replacement for fbcon for
systems that do not want/need CONFIG_VT. It simply prints the kernel-log to all
connected framebuffers. Previous versions are available here:
v3: http://thread.gmane.org/gmane.linux.kernel/1328164
v2: http://thread.gmane.org/gmane.linux.serial/8133
v1: http://marc.info/?l=linux-kernel&m=133988465602225&w=2
This patchset is based on linux-next.
Changes from previous version:
- Changed mailinglist to linux-fbdev instead of linux-serial
- Added "main_only" and "activate_on_hotplug" module parameters to provide
more fine-grained control over which framebuffers are used
As always simply remove the !VT dependency if you want to test this with VTs
enabled. Some more background information on deprecating CONFIG_VT can be found
here:
http://dvdhrm.wordpress.com/2012/08/12/killing-off-config_vt/
I am still looking for someone who is willing to push this to linux-next through
his or her tree. Feedback is much appreciated!
Thanks
David
David Herrmann (11):
fbcon: move update_attr() into separate source file
fbcon: move bit_putcs() into separate source file
fblog: new framebuffer kernel log dummy driver
fbdev: export get_fb_info()/put_fb_info()
fblog: register one fblog object per framebuffer
fblog: open fb on registration
fblog: allow selecting fbs via sysfs and module-parameters
fblog: cache framebuffer BLANK and SUSPEND states
fblog: register console driver
fblog: draw console to framebuffers
MAINTAINERS: add fblog entry
MAINTAINERS | 6 +
drivers/video/Kconfig | 5 +-
drivers/video/Makefile | 2 +-
drivers/video/console/Kconfig | 37 ++-
drivers/video/console/Makefile | 4 +-
drivers/video/console/bitblit.c | 149 +--------
drivers/video/console/fbcon.h | 5 +-
drivers/video/console/fbdraw.c | 171 ++++++++++
drivers/video/console/fbdraw.h | 30 ++
drivers/video/console/fblog.c | 691 ++++++++++++++++++++++++++++++++++++++++
drivers/video/fbmem.c | 6 +-
include/linux/fb.h | 3 +
12 files changed, 951 insertions(+), 158 deletions(-)
create mode 100644 drivers/video/console/fbdraw.c
create mode 100644 drivers/video/console/fbdraw.h
create mode 100644 drivers/video/console/fblog.c
--
1.7.11.4
^ permalink raw reply
* [PATCH 08/11] fblog: cache framebuffer BLANK and SUSPEND states
From: David Herrmann @ 2012-08-12 14:53 UTC (permalink / raw)
To: linux-fbdev
Cc: Florian Tobias Schandinat, Greg Kroah-Hartman, linux-serial,
Alan Cox, linux-kernel, Geert Uytterhoeven, David Herrmann
In-Reply-To: <1344783205-2384-1-git-send-email-dh.herrmann@googlemail.com>
We must cache these states so we will never draw to the framebuffer while
it is suspended or blanked.
Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
---
drivers/video/console/fblog.c | 41 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 41 insertions(+)
diff --git a/drivers/video/console/fblog.c b/drivers/video/console/fblog.c
index aed77dc..8bcd0ce 100644
--- a/drivers/video/console/fblog.c
+++ b/drivers/video/console/fblog.c
@@ -33,6 +33,8 @@
enum fblog_flags {
FBLOG_KILLED,
FBLOG_OPEN,
+ FBLOG_SUSPENDED,
+ FBLOG_BLANKED,
};
struct fblog_fb {
@@ -264,6 +266,7 @@ static int fblog_event(struct notifier_block *self, unsigned long action,
struct fb_event *event = data;
struct fb_info *info = event->info;
struct fblog_fb *fb;
+ int *blank;
switch(action) {
case FB_EVENT_FB_REGISTERED:
@@ -291,6 +294,44 @@ static int fblog_event(struct notifier_block *self, unsigned long action,
if (fb)
fblog_close(fb, true);
break;
+ case FB_EVENT_SUSPEND:
+ /* This is called when the low-level display driver suspends the
+ * video system. We should not access the video system while it
+ * is suspended. This is called with the console lock held. */
+ mutex_lock(&fblog_registration_lock);
+ fb = fblog_fbs[info->node];
+ mutex_unlock(&fblog_registration_lock);
+
+ if (fb)
+ set_bit(FBLOG_SUSPENDED, &fb->flags);
+ break;
+ case FB_EVENT_RESUME:
+ /* This is called when the low-level display driver resumes
+ * operating. It is called with the console lock held. */
+ mutex_lock(&fblog_registration_lock);
+ fb = fblog_fbs[info->node];
+ mutex_unlock(&fblog_registration_lock);
+
+ if (fb)
+ clear_bit(FBLOG_SUSPENDED, &fb->flags);
+ break;
+ case FB_EVENT_BLANK:
+ /* This gets called _after_ the framebuffer was successfully
+ * blanked. The console-lock is always held while fb_blank is
+ * called and during this callback. */
+ mutex_lock(&fblog_registration_lock);
+ fb = fblog_fbs[info->node];
+ mutex_unlock(&fblog_registration_lock);
+
+ if (!fb)
+ break;
+
+ blank = (int*)event->data;
+ if (*blank == FB_BLANK_UNBLANK)
+ clear_bit(FBLOG_BLANKED, &fb->flags);
+ else
+ set_bit(FBLOG_BLANKED, &fb->flags);
+ break;
}
return 0;
--
1.7.11.4
^ permalink raw reply related
* Re: [PATCH] [media] winbond-cir: Fix initialization
From: Mauro Carvalho Chehab @ 2012-08-11 20:20 UTC (permalink / raw)
To: David Härdeman
Cc: Sean Young, Jarod Wilson, Alan Cox, linux-media, linux-serial,
lirc-list
In-Reply-To: <1343731023-9822-1-git-send-email-sean@mess.org>
Hi David,
Em 31-07-2012 07:37, Sean Young escreveu:
> The serial driver will detect the winbond cir device as a serial port,
> since it looks exactly like a serial port unless you know what it is
> from the PNP ID.
>
> Winbond CIR 00:04: Region 0x2f8-0x2ff already in use!
> Winbond CIR 00:04: disabled
> Winbond CIR: probe of 00:04 failed with error -16
Please review this patch.
>
> Signed-off-by: Sean Young <sean@mess.org>
> ---
> drivers/media/rc/winbond-cir.c | 21 ++++++++++++++++++++-
> drivers/tty/serial/8250/8250.c | 1 +
> 2 files changed, 21 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/rc/winbond-cir.c b/drivers/media/rc/winbond-cir.c
> index 54ee348..20a0bbb 100644
> --- a/drivers/media/rc/winbond-cir.c
> +++ b/drivers/media/rc/winbond-cir.c
> @@ -55,6 +55,7 @@
> #include <linux/slab.h>
> #include <linux/wait.h>
> #include <linux/sched.h>
> +#include <linux/serial_8250.h>
> #include <media/rc-core.h>
>
> #define DRVNAME "winbond-cir"
> @@ -957,6 +958,7 @@ wbcir_probe(struct pnp_dev *device, const struct pnp_device_id *dev_id)
> struct device *dev = &device->dev;
> struct wbcir_data *data;
> int err;
> + struct resource *io;
>
> if (!(pnp_port_len(device, 0) == EHFUNC_IOMEM_LEN &&
> pnp_port_len(device, 1) == WAKEUP_IOMEM_LEN &&
> @@ -1049,7 +1051,24 @@ wbcir_probe(struct pnp_dev *device, const struct pnp_device_id *dev_id)
> goto exit_release_wbase;
> }
>
> - if (!request_region(data->sbase, SP_IOMEM_LEN, DRVNAME)) {
> + io = request_region(data->sbase, SP_IOMEM_LEN, DRVNAME);
> +
> + /*
> + * The winbond cir device looks exactly like an NS16550A serial port
> + * unless you know what it is. We've got here via the PNP ID.
> + */
> +#ifdef CONFIG_SERIAL_8250
> + if (!io) {
> + struct uart_port port = { .iobase = data->sbase };
> + int line = serial8250_find_port(&port);
> + if (line >= 0) {
> + serial8250_unregister_port(line);
Hmm... Not sure if it makes sense, but perhaps the unregistering code
should be reverting serial8250_unregister_port(line).
> +
> + io = request_region(data->sbase, SP_IOMEM_LEN, DRVNAME);
> + }
> + }
> +#endif
> + if (!io) {
> dev_err(dev, "Region 0x%lx-0x%lx already in use!\n",
> data->sbase, data->sbase + SP_IOMEM_LEN - 1);
> err = -EBUSY;
> diff --git a/drivers/tty/serial/8250/8250.c b/drivers/tty/serial/8250/8250.c
> index 5c27f7e..d38615f 100644
> --- a/drivers/tty/serial/8250/8250.c
> +++ b/drivers/tty/serial/8250/8250.c
> @@ -2914,6 +2914,7 @@ int serial8250_find_port(struct uart_port *p)
> }
> return -ENODEV;
> }
> +EXPORT_SYMBOL(serial8250_find_port);
>
> #define SERIAL8250_CONSOLE &serial8250_console
> #else
>
^ permalink raw reply
* Re: RFC: exposing uartclk value to sysfs
From: Tomas Hlavacek @ 2012-08-11 8:18 UTC (permalink / raw)
To: Alan Cox; +Cc: linux-serial, Greg Kroah-Hartman, Alan Cox
In-Reply-To: <20120810234858.4a5decd4@pyramind.ukuu.org.uk>
On Sat, Aug 11, 2012 at 12:48 AM, Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:
>> Although there is a way to set baud_base via setserial(8) I was
>> wandering whether it would be possible to expose uartclk in sysfs for
>> read/write. I have created a following proof-of-concept experimental
>> patch:
>
> That would probably be a *lot* more civilised. As a conceptual idea I
> think its a good one.
OK, I will dig into it and I will come up with more elaborate patch next time.
Tomas
^ permalink raw reply
* Re: RFC: exposing uartclk value to sysfs
From: Alan Cox @ 2012-08-10 22:48 UTC (permalink / raw)
To: Tomas Hlavacek; +Cc: linux-serial, Greg Kroah-Hartman, Alan Cox
In-Reply-To: <CAEB7QLAJXkK6NDPVDi36n_U_X_DGh5niHJhH6FpqBUZFmXQ2Xg@mail.gmail.com>
> Although there is a way to set baud_base via setserial(8) I was
> wandering whether it would be possible to expose uartclk in sysfs for
> read/write. I have created a following proof-of-concept experimental
> patch:
That would probably be a *lot* more civilised. As a conceptual idea I
think its a good one.
Alan
^ permalink raw reply
* RFC: exposing uartclk value to sysfs
From: Tomas Hlavacek @ 2012-08-10 22:28 UTC (permalink / raw)
To: linux-serial; +Cc: Greg Kroah-Hartman, Alan Cox
Hello!
I have encountered quite a lot PCI cards with many different
oscillator speeds while having no differences in PCI IDs (i.e. vendor
and subsystem IDs were chip-dafault). Namely I own several no-name
cards with OX16PCI954 and various speeds. These cards need different
baud_base (= uartclk*16) settings but it can not be
autodetected/pre-set because there is no way to distinguish them.
Although there is a way to set baud_base via setserial(8) I was
wandering whether it would be possible to expose uartclk in sysfs for
read/write. I have created a following proof-of-concept experimental
patch:
From 12c7e940c978da6cca9a6d51f499e7c5b53ec4b1 Mon Sep 17 00:00:00 2001
From: Tomas Hlavacek <tmshlvck@gmail.com>
Date: Fri, 10 Aug 2012 23:43:17 +0200
Subject: [PATCH 1/1] [RFC] [experimental]: uartclk exposed to sysfs.
TODO:
* Get opinions on the whole idea of exposing uartclk to sysfs.
* Get opinions on getting struct uart_port pointer in
the get_attr_uart routine by changing driver data of the tty device.
* Correct removal of the file (problem: How to get the device
handle?)
* Synchronization.
* Add write routine.
Signed-off-by: Tomas Hlavacek <tmshlvck@gmail.com>
---
drivers/tty/serial/serial_core.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index a21dc8e..2cb6ed5 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -2293,6 +2293,17 @@ struct tty_driver *uart_console_device(struct
console *co, int *index)
return p->tty_driver;
}
+static ssize_t get_attr_uartclk(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct uart_port *port = (struct uart_port *)(dev_get_drvdata(dev));
+ return snprintf(buf, PAGE_SIZE, "%d\n", port->uartclk);
+}
+
+static DEVICE_ATTR(uartclk, S_IRUGO, get_attr_uartclk, NULL);
+
/**
* uart_add_one_port - attach a driver-defined port structure
* @drv: pointer to the uart low level driver structure for this port
@@ -2354,6 +2365,12 @@ int uart_add_one_port(struct uart_driver *drv,
struct uart_port *uport)
uport->line);
}
+ dev_set_drvdata(tty_dev, uport);
+ int sret = device_create_file(tty_dev, &dev_attr_uartclk);
+ if (sret < 0)
+ dev_err(tty_dev, "failed to add uartclk attr.\n");
+
/*
* Ensure UPF_DEAD is not set.
*/
--
1.7.10.4
Tomas
--
Tomáš Hlaváček <tmshlvck@gmail.com>
--
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^ permalink raw reply related
* Re: Q: how to control the TTY output queue in real time?
From: Alan Cox @ 2012-08-10 20:15 UTC (permalink / raw)
To: Stas Sergeev; +Cc: Linux kernel, linux-serial
In-Reply-To: <502566EB.3070304@list.ru>
> If they do quite fine with the fifo, then maybe the new
> function will do too? Its basically a tcdrain(), just with
> the controllable watermark I guess.
I guess providing you account the fifo, and any hardware flow control it
would work.
^ permalink raw reply
* Re: Q: how to control the TTY output queue in real time?
From: Stas Sergeev @ 2012-08-10 19:54 UTC (permalink / raw)
To: Alan Cox; +Cc: Linux kernel, linux-serial
In-Reply-To: <20120810203355.224622cc@pyramind.ukuu.org.uk>
Hi Alan, thanks, clear enough now. :)
10.08.2012 23:33, Alan Cox wrote:
> if (bytes_left < constant)
> write_wakeup
>
>
> and I suspect if you made that adjustable and turned off the fifo and any
> other funnies you'd at least make it work for a sufficiently rigged demo.
You suggest to turn off the fifo, sounds worrysome,
does this mean that tcdrain() and TIOCOUTQ do not
account the fifo too?
If they do quite fine with the fifo, then maybe the new
function will do too? Its basically a tcdrain(), just with
the controllable watermark I guess.
^ permalink raw reply
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