On 06/28/2012 05:53 PM, Franky Lin wrote:

On 06/28/2012 02:55 PM, Jon Hunter wrote:

quoted

Ok. Any way to manually reset the wlan module to deactivate the gpio
when it is hung? I am wondering if the gpio is deactivated if the board
comes back to life, indicating it is stuck in the interrupt somewhere.

The only way I can think of is removing the module manually. But it
didn't bring the board back to live.

quoted

Well, at least that is consistent with what I see, but also perplexing
that it takes sometime to fail. Can you try the following as a debug
patch to see if it is in the context restore that is the problem. From
your testing and bisect, the only possible difference in the current
kernel is that it could perform the context restore when acquiring the
gpio.

diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index c4ed172..a2401bd 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c

@@ -1341,6 +1341,8 @@ void omap2_gpio_resume_after_idle(void)
  #if defined(CONFIG_PM_RUNTIME)
  static void omap_gpio_restore_context(struct gpio_bank *bank)
  {
+       return;
+
         __raw_writel(bank->context.wake_en,
                                 bank->base + bank->regs->wkup_en);
         __raw_writel(bank->context.ctrl, bank->base + bank->regs->ctrl);

This one works! It can run more than 20 mins.

Great! I need to dig into the context restore some more.

I found one interesting thing. When I added the print info to see when
runtime_suspend/resume get called, it seems like the suspend/resume is
unbalance during boot. Resume got called more than suspend. So I hack
the code to make sure suspend and resume are called in pair. A resume
without suspend will do nothing and return immediately. This also makes
the hang vanish.

I am not 100% sure I follow. On boot I would expect to see a
resume/suspend due to the probe on the irq bank and then I would expect
to see another resume from the acquisition of the gpio, however, I would
not expect a suspend until the gpio is freed, which I don't believe you
are doing.

Can you share your hack? Just paste the diff? This may help me
understand more.

Thanks
Jon