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Message-ID: <20080401144224.GA6436@USFSHXP-002051>
Date: Tue, 1 Apr 2008 10:42:25 -0400
From: Dmitry Torokhov <dmitry.torokhov@...il.com>
To: Dmitry <dbaryshkov@...il.com>
Cc: linux-input@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] Fix tosakbd suspend
On Tue, Apr 01, 2008 at 04:27:38PM +0300, Dmitry wrote:
> Hi, Dmitry,
>
> 2008/4/1, Dmitry Torokhov <dmitry.torokhov@...il.com>:
> > Hi Dmitry,
> >
> >
> > On Tue, Apr 01, 2008 at 01:38:01AM +0400, Dmitry Baryshkov wrote:
> > > Signed-off-by: Dmitry Baryshkov <dbaryshkov@...il.com>
> > > ---
> > > drivers/input/keyboard/tosakbd.c | 3 +++
> > > 1 files changed, 3 insertions(+), 0 deletions(-)
> > >
> > > diff --git a/drivers/input/keyboard/tosakbd.c b/drivers/input/keyboard/tosakbd.c
> > > index 3884d1e..306cbe8 100644
> > > --- a/drivers/input/keyboard/tosakbd.c
> > > +++ b/drivers/input/keyboard/tosakbd.c
> > > @@ -210,6 +210,9 @@ static int tosakbd_suspend(struct platform_device *dev, pm_message_t state)
> > >
> > > del_timer_sync(&tosakbd->timer);
> > >
> >
> >
> > What if interrupt comes here? The whole suspend path seems racy with
> > interrup handler/timer.
>
> What is the best way to fix it? Moving from suspend to suspend_late
> seems to be a hack.
> Should I call a bunch of disable_irq or just introduce an atomic flag?
>
How about we take the lock in tosakbd_suspend, set flag indicating that the
picece is suspended, do the discharge and then del_timer_sync()? If you change
tosakbd_scankeyboard() to check for suspend flag and exit as soon as it sees it
it should take care of the most of the issues I think. Something like this:
Subject: Input: tosakbd - fix suspend
From: Dmitry Baryshkov <dbaryshkov@...il.com>
Input: tosakbd - fix suspend
Signed-off-by: Dmitry Baryshkov <dbaryshkov@...il.com>
Signed-off-by: Dmitry Torokhov <dtor@...l.ru>
---
drivers/input/keyboard/tosakbd.c | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)
Index: linux/drivers/input/keyboard/tosakbd.c
===================================================================
--- linux.orig/drivers/input/keyboard/tosakbd.c
+++ linux/drivers/input/keyboard/tosakbd.c
@@ -52,7 +52,7 @@ KEY_X, KEY_F, KEY_SPACE, KEY_APOSTROPHE,
struct tosakbd {
unsigned int keycode[ARRAY_SIZE(tosakbd_keycode)];
struct input_dev *input;
-
+ int suspeneded;
spinlock_t lock; /* protect kbd scanning */
struct timer_list timer;
};
@@ -133,6 +133,9 @@ static void tosakbd_scankeyboard(struct
spin_lock_irqsave(&tosakbd->lock, flags);
+ if (tosakbd->suspended)
+ goto out;
+
for (col = 0; col < TOSA_KEY_STROBE_NUM; col++) {
/*
* Discharge the output driver capacitatance
@@ -174,6 +177,7 @@ static void tosakbd_scankeyboard(struct
if (num_pressed)
mod_timer(&tosakbd->timer, jiffies + SCAN_INTERVAL);
+ out:
spin_unlock_irqrestore(&tosakbd->lock, flags);
}
@@ -200,6 +204,7 @@ static irqreturn_t tosakbd_interrupt(int
static void tosakbd_timer_callback(unsigned long __dev)
{
struct platform_device *dev = (struct platform_device *)__dev;
+
tosakbd_scankeyboard(dev);
}
@@ -207,6 +212,13 @@ static void tosakbd_timer_callback(unsig
static int tosakbd_suspend(struct platform_device *dev, pm_message_t state)
{
struct tosakbd *tosakbd = platform_get_drvdata(dev);
+ unsigned long flags;
+
+ spin_lock_irqsave(&tosakbd->lock, flags);
+ PGSR1 = (PGSR1 & ~TOSA_GPIO_LOW_STROBE_BIT);
+ PGSR2 = (PGSR2 & ~TOSA_GPIO_HIGH_STROBE_BIT);
+ tosakbd->suspended = 1;
+ spin_unlock_irqrestore(&tosakbd->lock, flags);
del_timer_sync(&tosakbd->timer);
@@ -215,6 +227,7 @@ static int tosakbd_suspend(struct platfo
static int tosakbd_resume(struct platform_device *dev)
{
+ tosakbd->suspended = 0;
tosakbd_scankeyboard(dev);
return 0;
@@ -365,8 +378,8 @@ fail:
return error;
}
-static int __devexit tosakbd_remove(struct platform_device *dev) {
-
+static int __devexit tosakbd_remove(struct platform_device *dev)
+{
int i;
struct tosakbd *tosakbd = platform_get_drvdata(dev);
--
Dmitry
--
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