linux-kernel - Re: [PATCH] Fix tosakbd suspend

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Date:	Wed, 2 Apr 2008 18:38:26 +0400
From:	Dmitry <dbaryshkov@...il.com>
To:	dmitry.torokhov@...il.com
Cc:	linux-input@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] Fix tosakbd suspend

Hi,

Sorry, that was me... Sometimes I hate git-am & git-format-patch

2008/4/2, Dmitry Torokhov <dbaryshkov@...il.com>:
> Hi,
>
>
>  2008/4/1, Dmitry Torokhov <dmitry.torokhov@...il.com>:
>  > 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:
>
>
> Fixed two minor glitches. Works for me. Please add it to your tree.
>
>
>  Subject: Input: tosakbd - fix suspend
>
> 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 |   21 ++++++++++++++++++---
>   1 files changed, 18 insertions(+), 3 deletions(-)
>
>
>  diff --git a/drivers/input/keyboard/tosakbd.c b/drivers/input/keyboard/tosakbd.c
>
> index 3884d1e..a247006 100644
>
> --- a/drivers/input/keyboard/tosakbd.c
>  +++ b/drivers/input/keyboard/tosakbd.c
>
> @@ -52,7 +52,7 @@ KEY_X, KEY_F, KEY_SPACE, KEY_APOSTROPHE, TOSA_KEY_MAIL, KEY_LEFT, KEY_DOWN, KEY_
>
>  struct tosakbd {
>         unsigned int keycode[ARRAY_SIZE(tosakbd_keycode)];
>         struct input_dev *input;
>  -
>
> +       int suspended;
>
>         spinlock_t lock; /* protect kbd scanning */
>         struct timer_list timer;
>   };
>
> @@ -133,6 +133,9 @@ static void tosakbd_scankeyboard(struct platform_device *dev)
>
>
>         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 platform_device *dev)
>
>         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 irq, void *__dev)
>
>  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(unsigned long __dev)
>
>  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 +227,9 @@ static int tosakbd_suspend(struct platform_device *dev, pm_message_t state)
>
>
>   static int tosakbd_resume(struct platform_device *dev)
>   {
>
> +       struct tosakbd *tosakbd = platform_get_drvdata(dev);
>
> +
>  +       tosakbd->suspended = 0;
>         tosakbd_scankeyboard(dev);
>
>         return 0;
>
> @@ -365,8 +380,8 @@ 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);
>
>  --
>
> 1.5.4.4
>
>
>  --
>  With best wishes
>  Dmitry
>
>


-- 
With best wishes
Dmitry
--
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