* [PATCH] ACPI: dock: Don't eval _STA on every show_docked sysfs read
@ 2009-01-20 11:18 Holger Macht
2009-01-27 21:04 ` Andrew Morton
0 siblings, 1 reply; 6+ messages in thread
From: Holger Macht @ 2009-01-20 11:18 UTC (permalink / raw)
To: linux-acpi; +Cc: stable, Len Brown, Li, Shaohua, Daniel Smolik, akpm
Some devices trigger a DEVICE_CHECK on every evalutation of _STA. This
can also be seen in commit 8b59560a3baf2e7c24e0fb92ea5d09eca92805db
(ACPI: dock: avoid check _STA method). If an undock is processed, the
dock driver sends a uevent and userspace might read the show_docked
property in sysfs. This causes an evaluation of _STA of the particular
device which causes the dock driver to immediately dock again.
In any case, evaluation of _STA (show_docked) does not necessarily mean
that we are docked, so check with the internal device structure.
http://bugzilla.kernel.org/show_bug.cgi?id=12360
Signed-off-by: Holger Macht <hmacht@suse.de>
---
diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
index 5b30b8d..afd5db3 100644
--- a/drivers/acpi/dock.c
+++ b/drivers/acpi/dock.c
@@ -855,10 +855,14 @@ fdd_out:
static ssize_t show_docked(struct device *dev,
struct device_attribute *attr, char *buf)
{
+ struct acpi_device *tmp;
+
struct dock_station *dock_station = *((struct dock_station **)
dev->platform_data);
- return snprintf(buf, PAGE_SIZE, "%d\n", dock_present(dock_station));
+ if (ACPI_SUCCESS(acpi_bus_get_device(dock_station->handle, &tmp)))
+ return snprintf(buf, PAGE_SIZE, "1\n");
+ return snprintf(buf, PAGE_SIZE, "0\n");
}
static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] ACPI: dock: Don't eval _STA on every show_docked sysfs read
2009-01-20 11:18 [PATCH] ACPI: dock: Don't eval _STA on every show_docked sysfs read Holger Macht
@ 2009-01-27 21:04 ` Andrew Morton
2009-02-06 16:47 ` Holger Macht
2009-02-07 3:11 ` Len Brown
0 siblings, 2 replies; 6+ messages in thread
From: Andrew Morton @ 2009-01-27 21:04 UTC (permalink / raw)
To: hmacht; +Cc: linux-acpi, stable, lenb, Li, shaohua.li, marvin
On Tue, 20 Jan 2009 12:18:24 +0100
Holger Macht <hmacht@suse.de> wrote:
> Cc: stable@kernel.org
The patch applied OK to 2.6.28 but not to any earlier kernel. If we
decide that it should be backported to 2.6.27 or earlier, a new patch
might be needed for that.
> Some devices trigger a DEVICE_CHECK on every evalutation of _STA. This
> can also be seen in commit 8b59560a3baf2e7c24e0fb92ea5d09eca92805db
> (ACPI: dock: avoid check _STA method). If an undock is processed, the
> dock driver sends a uevent and userspace might read the show_docked
> property in sysfs. This causes an evaluation of _STA of the particular
> device which causes the dock driver to immediately dock again.
>
> In any case, evaluation of _STA (show_docked) does not necessarily mean
> that we are docked, so check with the internal device structure.
>
> http://bugzilla.kernel.org/show_bug.cgi?id=12360
>
> Signed-off-by: Holger Macht <hmacht@suse.de>
> ---
>
> diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
> index 5b30b8d..afd5db3 100644
> --- a/drivers/acpi/dock.c
> +++ b/drivers/acpi/dock.c
> @@ -855,10 +855,14 @@ fdd_out:
> static ssize_t show_docked(struct device *dev,
> struct device_attribute *attr, char *buf)
> {
> + struct acpi_device *tmp;
> +
> struct dock_station *dock_station = *((struct dock_station **)
> dev->platform_data);
> - return snprintf(buf, PAGE_SIZE, "%d\n", dock_present(dock_station));
>
> + if (ACPI_SUCCESS(acpi_bus_get_device(dock_station->handle, &tmp)))
> + return snprintf(buf, PAGE_SIZE, "1\n");
> + return snprintf(buf, PAGE_SIZE, "0\n");
> }
> static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);
That seems a little overwrought. Won't plain old strcpy suffice?
--- a/drivers/acpi/dock.c~acpi-dock-dont-eval-_sta-on-every-show_docked-sysfs-read-simplification
+++ a/drivers/acpi/dock.c
@@ -861,8 +861,8 @@ static ssize_t show_docked(struct device
dev->platform_data);
if (ACPI_SUCCESS(acpi_bus_get_device(dock_station->handle, &tmp)))
- return snprintf(buf, PAGE_SIZE, "1\n");
- return snprintf(buf, PAGE_SIZE, "0\n");
+ return strcpy(buf, "1\n");
+ return strcpy(buf, "0\n");
}
static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);
_
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] ACPI: dock: Don't eval _STA on every show_docked sysfs read
2009-01-27 21:04 ` Andrew Morton
@ 2009-02-06 16:47 ` Holger Macht
2009-02-06 21:33 ` Andrew Morton
2009-02-07 3:11 ` Len Brown
1 sibling, 1 reply; 6+ messages in thread
From: Holger Macht @ 2009-02-06 16:47 UTC (permalink / raw)
To: Andrew Morton; +Cc: linux-acpi, stable, lenb, Li, shaohua.li, marvin
[-- Attachment #1: Type: text/plain, Size: 442 bytes --]
Hi,
sorry for the delay...
On Tue, 2009-01-27 at 13:04 -0800, Andrew Morton wrote:
> On Tue, 20 Jan 2009 12:18:24 +0100
> Holger Macht <hmacht@suse.de> wrote:
>
> > Cc: stable@kernel.org
>
> The patch applied OK to 2.6.28 but not to any earlier kernel. If we
> decide that it should be backported to 2.6.27 or earlier, a new patch
> might be needed for that.
Patch that applies to stable kernel from today is attached.
Thanks,
Holger
[-- Attachment #2: acpi-dock-dont-eval-STA-on-every-show-docked-sysfs-read.patch --]
[-- Type: text/x-patch, Size: 1325 bytes --]
Some devices trigger a DEVICE_CHECK on every evalutation of _STA. This
can also be seen in commit 8b59560a3baf2e7c24e0fb92ea5d09eca92805db
(acpi: dock: avoid check _STA method). If an undock is processed, the
dock driver sends a uevent and userspace might read the show_docked
property in sysfs. This causes an evaluation of _STA of the particular
device which causes the dock driver to immediately dock again.
In any case, evaluation of _STA (show_docked) does not necessarily mean
that we are docked, so check with the internal device structure.
http://bugzilla.kernel.org/show_bug.cgi?id=12360
Signed-off-by: Holger Macht <hmacht@suse.de>
---
diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
index 25d2161..7290e54 100644
--- a/drivers/acpi/dock.c
+++ b/drivers/acpi/dock.c
@@ -691,8 +691,14 @@ fdd_out:
static ssize_t show_docked(struct device *dev,
struct device_attribute *attr, char *buf)
{
- return snprintf(buf, PAGE_SIZE, "%d\n", dock_present(dock_station));
+ struct acpi_device *tmp;
+
+ struct dock_station *dock_station = *((struct dock_station **)
+ dev->platform_data);
+ if (ACPI_SUCCESS(acpi_bus_get_device(dock_station->handle, &tmp)))
+ return snprintf(buf, PAGE_SIZE, "1\n");
+ return snprintf(buf, PAGE_SIZE, "0\n");
}
static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] ACPI: dock: Don't eval _STA on every show_docked sysfs read
2009-02-06 16:47 ` Holger Macht
@ 2009-02-06 21:33 ` Andrew Morton
0 siblings, 0 replies; 6+ messages in thread
From: Andrew Morton @ 2009-02-06 21:33 UTC (permalink / raw)
To: hmacht; +Cc: linux-acpi, stable, lenb, Li, shaohua.li, marvin
On Fri, 06 Feb 2009 17:47:56 +0100
Holger Macht <hmacht@suse.de> wrote:
> Hi,
>
> sorry for the delay...
>
> On Tue, 2009-01-27 at 13:04 -0800, Andrew Morton wrote:
> > On Tue, 20 Jan 2009 12:18:24 +0100
> > Holger Macht <hmacht@suse.de> wrote:
> >
> > > Cc: stable@kernel.org
> >
> > The patch applied OK to 2.6.28 but not to any earlier kernel. If we
> > decide that it should be backported to 2.6.27 or earlier, a new patch
> > might be needed for that.
>
> Patch that applies to stable kernel from today is attached.
>
ok, thanks.
But this won't be going into -stable until the mainline version gets
merged.
Len, where are we up to with that?
Thanks.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] ACPI: dock: Don't eval _STA on every show_docked sysfs read
2009-01-27 21:04 ` Andrew Morton
2009-02-06 16:47 ` Holger Macht
@ 2009-02-07 3:11 ` Len Brown
2009-02-07 3:18 ` Andrew Morton
1 sibling, 1 reply; 6+ messages in thread
From: Len Brown @ 2009-02-07 3:11 UTC (permalink / raw)
To: Andrew Morton; +Cc: hmacht, linux-acpi, stable, Li, shaohua.li, marvin
--
Len Brown, Intel Open Source Technology Center
On Tue, 27 Jan 2009, Andrew Morton wrote:
> On Tue, 20 Jan 2009 12:18:24 +0100
> Holger Macht <hmacht@suse.de> wrote:
>
> > Cc: stable@kernel.org
>
> The patch applied OK to 2.6.28 but not to any earlier kernel. If we
> decide that it should be backported to 2.6.27 or earlier, a new patch
> might be needed for that.
>
> > Some devices trigger a DEVICE_CHECK on every evalutation of _STA. This
> > can also be seen in commit 8b59560a3baf2e7c24e0fb92ea5d09eca92805db
> > (ACPI: dock: avoid check _STA method). If an undock is processed, the
> > dock driver sends a uevent and userspace might read the show_docked
> > property in sysfs. This causes an evaluation of _STA of the particular
> > device which causes the dock driver to immediately dock again.
> >
> > In any case, evaluation of _STA (show_docked) does not necessarily mean
> > that we are docked, so check with the internal device structure.
> >
> > http://bugzilla.kernel.org/show_bug.cgi?id=12360
> >
> > Signed-off-by: Holger Macht <hmacht@suse.de>
> > ---
> >
> > diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
> > index 5b30b8d..afd5db3 100644
> > --- a/drivers/acpi/dock.c
> > +++ b/drivers/acpi/dock.c
> > @@ -855,10 +855,14 @@ fdd_out:
> > static ssize_t show_docked(struct device *dev,
> > struct device_attribute *attr, char *buf)
> > {
> > + struct acpi_device *tmp;
> > +
> > struct dock_station *dock_station = *((struct dock_station **)
> > dev->platform_data);
> > - return snprintf(buf, PAGE_SIZE, "%d\n", dock_present(dock_station));
> >
> > + if (ACPI_SUCCESS(acpi_bus_get_device(dock_station->handle, &tmp)))
> > + return snprintf(buf, PAGE_SIZE, "1\n");
> > + return snprintf(buf, PAGE_SIZE, "0\n");
> > }
> > static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);
>
> That seems a little overwrought. Won't plain old strcpy suffice?
>
>
> --- a/drivers/acpi/dock.c~acpi-dock-dont-eval-_sta-on-every-show_docked-sysfs-read-simplification
> +++ a/drivers/acpi/dock.c
> @@ -861,8 +861,8 @@ static ssize_t show_docked(struct device
> dev->platform_data);
>
> if (ACPI_SUCCESS(acpi_bus_get_device(dock_station->handle, &tmp)))
> - return snprintf(buf, PAGE_SIZE, "1\n");
> - return snprintf(buf, PAGE_SIZE, "0\n");
> + return strcpy(buf, "1\n");
> + return strcpy(buf, "0\n");
> }
> static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);
>
> _
>
sure, strcpy is fine b/c the src and dest are known to not be in danger of
overlow. applied to acpi misc branch.
thanks,
-Len
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] ACPI: dock: Don't eval _STA on every show_docked sysfs read
2009-02-07 3:11 ` Len Brown
@ 2009-02-07 3:18 ` Andrew Morton
0 siblings, 0 replies; 6+ messages in thread
From: Andrew Morton @ 2009-02-07 3:18 UTC (permalink / raw)
To: Len Brown; +Cc: hmacht, linux-acpi, stable, Li, shaohua.li, marvin
On Fri, 06 Feb 2009 22:11:15 -0500 (EST) Len Brown <lenb@kernel.org> wrote:
>
>
> --
> Len Brown, Intel Open Source Technology Center
>
> On Tue, 27 Jan 2009, Andrew Morton wrote:
>
> > On Tue, 20 Jan 2009 12:18:24 +0100
> > Holger Macht <hmacht@suse.de> wrote:
> >
> > > Cc: stable@kernel.org
> >
> > The patch applied OK to 2.6.28 but not to any earlier kernel. If we
> > decide that it should be backported to 2.6.27 or earlier, a new patch
> > might be needed for that.
> >
> > > Some devices trigger a DEVICE_CHECK on every evalutation of _STA. This
> > > can also be seen in commit 8b59560a3baf2e7c24e0fb92ea5d09eca92805db
> > > (ACPI: dock: avoid check _STA method). If an undock is processed, the
> > > dock driver sends a uevent and userspace might read the show_docked
> > > property in sysfs. This causes an evaluation of _STA of the particular
> > > device which causes the dock driver to immediately dock again.
> > >
> > > In any case, evaluation of _STA (show_docked) does not necessarily mean
> > > that we are docked, so check with the internal device structure.
> > >
> > > http://bugzilla.kernel.org/show_bug.cgi?id=12360
> > >
> > > Signed-off-by: Holger Macht <hmacht@suse.de>
> > > ---
> > >
> > > diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
> > > index 5b30b8d..afd5db3 100644
> > > --- a/drivers/acpi/dock.c
> > > +++ b/drivers/acpi/dock.c
> > > @@ -855,10 +855,14 @@ fdd_out:
> > > static ssize_t show_docked(struct device *dev,
> > > struct device_attribute *attr, char *buf)
> > > {
> > > + struct acpi_device *tmp;
> > > +
> > > struct dock_station *dock_station = *((struct dock_station **)
> > > dev->platform_data);
> > > - return snprintf(buf, PAGE_SIZE, "%d\n", dock_present(dock_station));
> > >
> > > + if (ACPI_SUCCESS(acpi_bus_get_device(dock_station->handle, &tmp)))
> > > + return snprintf(buf, PAGE_SIZE, "1\n");
> > > + return snprintf(buf, PAGE_SIZE, "0\n");
> > > }
> > > static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);
> >
> > That seems a little overwrought. Won't plain old strcpy suffice?
> >
> >
> > --- a/drivers/acpi/dock.c~acpi-dock-dont-eval-_sta-on-every-show_docked-sysfs-read-simplification
> > +++ a/drivers/acpi/dock.c
> > @@ -861,8 +861,8 @@ static ssize_t show_docked(struct device
> > dev->platform_data);
> >
> > if (ACPI_SUCCESS(acpi_bus_get_device(dock_station->handle, &tmp)))
> > - return snprintf(buf, PAGE_SIZE, "1\n");
> > - return snprintf(buf, PAGE_SIZE, "0\n");
> > + return strcpy(buf, "1\n");
> > + return strcpy(buf, "0\n");
> > }
> > static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);
> >
> > _
> >
>
> sure, strcpy is fine b/c the src and dest are known to not be in danger of
> overlow. applied to acpi misc branch.
argh, sorry, don't apply the strcpy() version - it's buggy. It returns
the address of the string (and a compile warning) rather than the
amount-of-data-available.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2009-02-07 4:11 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2009-01-20 11:18 [PATCH] ACPI: dock: Don't eval _STA on every show_docked sysfs read Holger Macht
2009-01-27 21:04 ` Andrew Morton
2009-02-06 16:47 ` Holger Macht
2009-02-06 21:33 ` Andrew Morton
2009-02-07 3:11 ` Len Brown
2009-02-07 3:18 ` Andrew Morton
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