From: Alan Cox <alan@linux.intel.com>
To: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org,
arnd@arndb.de
Subject: [PATCH 10/20] synclink: reworking locking a bit
Date: Wed, 05 May 2010 11:02:36 +0100 [thread overview]
Message-ID: <20100505100236.3595.27264.stgit@localhost.localdomain> (raw)
In-Reply-To: <20100505100144.3595.65633.stgit@localhost.localdomain>
Use the port mutex and port lock to fix the various races. The locking
still isn't totally consistent but its better than before. Wants switching
to the port helpers.
Signed-off-by: Alan Cox <alan@linux.intel.com>
---
drivers/char/synclink_gt.c | 12 +++++++++++-
drivers/char/synclinkmp.c | 9 ++++++++-
2 files changed, 19 insertions(+), 2 deletions(-)
diff --git a/drivers/char/synclink_gt.c b/drivers/char/synclink_gt.c
index d0f81f5..c56b70a 100644
--- a/drivers/char/synclink_gt.c
+++ b/drivers/char/synclink_gt.c
@@ -675,12 +675,14 @@ static int open(struct tty_struct *tty, struct file *filp)
goto cleanup;
}
+ mutex_lock(&info->port.mutex);
info->port.tty->low_latency = (info->port.flags & ASYNC_LOW_LATENCY) ? 1 : 0;
spin_lock_irqsave(&info->netlock, flags);
if (info->netcount) {
retval = -EBUSY;
spin_unlock_irqrestore(&info->netlock, flags);
+ mutex_unlock(&info->port.mutex);
goto cleanup;
}
info->port.count++;
@@ -692,7 +694,7 @@ static int open(struct tty_struct *tty, struct file *filp)
if (retval < 0)
goto cleanup;
}
-
+ mutex_unlock(&info->port.mutex);
retval = block_til_ready(tty, filp, info);
if (retval) {
DBGINFO(("%s block_til_ready rc=%d\n", info->device_name, retval));
@@ -724,12 +726,14 @@ static void close(struct tty_struct *tty, struct file *filp)
if (tty_port_close_start(&info->port, tty, filp) == 0)
goto cleanup;
+ mutex_lock(&info->port.mutex);
if (info->port.flags & ASYNC_INITIALIZED)
wait_until_sent(tty, info->timeout);
flush_buffer(tty);
tty_ldisc_flush(tty);
shutdown(info);
+ mutex_unlock(&info->port.mutex);
tty_port_close_end(&info->port, tty);
info->port.tty = NULL;
@@ -740,17 +744,23 @@ cleanup:
static void hangup(struct tty_struct *tty)
{
struct slgt_info *info = tty->driver_data;
+ unsigned long flags;
if (sanity_check(info, tty->name, "hangup"))
return;
DBGINFO(("%s hangup\n", info->device_name));
flush_buffer(tty);
+
+ mutex_lock(&info->port.mutex);
shutdown(info);
+ spin_lock_irqsave(&info->port.lock, flags);
info->port.count = 0;
info->port.flags &= ~ASYNC_NORMAL_ACTIVE;
info->port.tty = NULL;
+ spin_unlock_irqrestore(&info->port.lock, flags);
+ mutex_unlock(&info->port.mutex);
wake_up_interruptible(&info->port.open_wait);
}
diff --git a/drivers/char/synclinkmp.c b/drivers/char/synclinkmp.c
index 8da976b..cfa581e 100644
--- a/drivers/char/synclinkmp.c
+++ b/drivers/char/synclinkmp.c
@@ -812,13 +812,15 @@ static void close(struct tty_struct *tty, struct file *filp)
if (tty_port_close_start(&info->port, tty, filp) == 0)
goto cleanup;
-
+
+ mutex_lock(&info->port.mutex);
if (info->port.flags & ASYNC_INITIALIZED)
wait_until_sent(tty, info->timeout);
flush_buffer(tty);
tty_ldisc_flush(tty);
shutdown(info);
+ mutex_unlock(&info->port.mutex);
tty_port_close_end(&info->port, tty);
info->port.tty = NULL;
@@ -834,6 +836,7 @@ cleanup:
static void hangup(struct tty_struct *tty)
{
SLMP_INFO *info = tty->driver_data;
+ unsigned long flags;
if (debug_level >= DEBUG_LEVEL_INFO)
printk("%s(%d):%s hangup()\n",
@@ -842,12 +845,16 @@ static void hangup(struct tty_struct *tty)
if (sanity_check(info, tty->name, "hangup"))
return;
+ mutex_lock(&info->port.mutex);
flush_buffer(tty);
shutdown(info);
+ spin_lock_irqsave(&info->port.lock, flags);
info->port.count = 0;
info->port.flags &= ~ASYNC_NORMAL_ACTIVE;
info->port.tty = NULL;
+ spin_unlock_irqrestore(&info->port.lock, flags);
+ mutex_unlock(&info->port.mutex);
wake_up_interruptible(&info->port.open_wait);
}
next prev parent reply other threads:[~2010-05-05 10:41 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-05 10:01 [PATCH 01/20] stallion: prune lock_kernel calls Alan Cox
2010-05-05 10:01 ` [PATCH 02/20] istallion: use bit ops for the board flags Alan Cox
2010-05-05 10:01 ` [PATCH 03/20] riscom8: kill use of lock_kernel Alan Cox
2010-05-05 10:02 ` [PATCH 04/20] isicom: kill off the BKL Alan Cox
2010-05-05 10:02 ` [PATCH 05/20] rocket: kill BKL Alan Cox
2010-05-05 10:02 ` [PATCH 06/20] synclink: kill the big kernel lock Alan Cox
2010-05-05 10:02 ` [PATCH 07/20] cyclades: Kill off BKL usage Alan Cox
2010-05-05 10:02 ` [PATCH 08/20] epca: Kill the big kernel lock Alan Cox
2010-05-05 10:02 ` [PATCH 09/20] specialix; Kill the BKL Alan Cox
2010-05-05 10:02 ` Alan Cox [this message]
2010-05-05 10:02 ` [PATCH 11/20] tty: serial - fix various misuses/mishandlings of port->tty Alan Cox
2010-05-05 10:02 ` [PATCH 12/20] tty: serial - fix tty back references in termios Alan Cox
2010-05-05 10:02 ` [PATCH 13/20] tty: serial - fix tty referencing in set_ldisc Alan Cox
2010-05-05 10:02 ` [PATCH 14/20] vc: Locking clean up Alan Cox
2010-05-05 10:03 ` [PATCH 15/20] tty: Make vt's have a tty_port Alan Cox
2010-05-05 10:03 ` [PATCH 16/20] tty: Move the vt_tty field from the vc_data into the standard tty_port Alan Cox
2010-05-05 10:03 ` [PATCH 17/20] serial: Change the wait for carrier locking Alan Cox
2010-05-05 10:03 ` [PATCH 18/20] serial: add port helpers Alan Cox
2010-05-05 10:03 ` [PATCH 19/20] serial: trim locking on the helpers Alan Cox
2010-05-05 10:03 ` [PATCH 20/20] serial: Use block_til_ready helper Alan Cox
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20100505100236.3595.27264.stgit@localhost.localdomain \
--to=alan@linux.intel.com \
--cc=arnd@arndb.de \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-serial@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).