Panda ES board hang when using GPIO as interrupt

[DebBarma, Tarun Kanti]

On Fri, Jun 29, 2012 at 6:29 AM, Franky Lin <frankyl at broadcom.com> wrote:
> On 06/28/2012 04:54 PM, Jon Hunter wrote:
>>
>> I am wondering if this could be the bug ... on start-up I see that we do
>> a context restore on bank1 during the probe which is before we have done
>> the first suspend! In other words, we could restore a bad/uninitialised
>> context for bank1. In the case of bank1, the loss count starts at 1 and
>> not 0 and so we falsely think we need to perform a restore :-(
>>
>> [    0.176269] omap_gpio_runtime_resume: bank @ 0xfc310000
>> [    0.177276] omap_gpio_runtime_resume: count 0, now 1
>> [    0.177276] gpiochip_add: registered GPIOs 0 to 31 on device: gpio
>> [    0.177642] omap_gpio_runtime_suspend: bank @ 0xfc310000
>>
>> Can you try ...
>>
>> diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
>> index c4ed172..9623408 100644
>> --- a/drivers/gpio/gpio-omap.c
>> +++ b/drivers/gpio/gpio-omap.c
>> @@ -1086,6 +1086,9 @@ static int __devinit omap_gpio_probe(struct
>> platform_device *pdev)
>>  #ifdef CONFIG_OF_GPIO
>>         bank->chip.of_node = of_node_get(node);
>>  #endif
>> +       if (bank->get_context_loss_count)
>> +               bank->context_loss_count =
>> +                               bank->get_context_loss_count(bank->dev);
>>
>>         bank->irq_base = irq_alloc_descs(-1, 0, bank->width, 0);
>>         if (bank->irq_base < 0) {
>>
>
> Looks like you found the culprit. :) It does fix the problem.
So this looks similar to what NeilBrown <neilb at suse.de> reported in
another thread.
The reason was context_loss_count = 1 for GPIO BANK#0 which of course is in the
WKUP domain. In fact he tried out with the same fix. Anyways, we
should hear from
Kevin now whether it is feasible to fix the context_loss_count for the WKUP GPIO
bank or to put the workaround here in the gpio driver.
--
Tarun
>
> Franky
>