Re: [PATCH v7 00/26] gpio/omap: driver cleanup and fixes

Santosh Shilimkar
2011-09-24T08:50:26Z

On Saturday 24 September 2011 09:26 AM, DebBarma, Tarun Kanti wrote:
> [...]
>> After debugging this myself a bit, here's what I think may be going on.
>> This may not be the only problem but here's at least one of them.
>>
>> First, debounce clocks are disabled in the runtime_suspend callback.
>>
>> When a GPIO is freed and it's the last one in the bank, bank->mod_usage
>> goes to zero.
>>
>> After that, pm_runtime_put_sync() is called, which will trigger the
>> driver's ->runtime_suspend callback. The ->runtime_suspend() callback
>> checks bank->mod_usage as well, and if zero, doesn't do anything
>> (notably, it doesn't disable debounce clocks.)
> I need some clarification in reproducing/testing the fix on OMAP3430SDP.
> The first thing I am trying to verify is the code flow of suspend.
>
> 1) With no debounce clock enabled, when I enable UART timeouts, I
> automatically see
> system going to retention. That is I don't have to type echo mem >
> /sys/power/state
> echo 5 > /sys/devices/platform/omap/omap_uart.0/sleep_timeout
> echo 5 > /sys/devices/platform/omap/omap_uart.1/sleep_timeout
> echo 5 > /sys/devices/platform/omap/omap_uart.2/sleep_timeout
>
> 2) I am do not see the print in omap_gpio_suspend/resume(), but I see
> the print in
> *_prepare_for_idle()/*_resume_after_idle().
>
Hmmm,

This is mostly happening because you are missing a below
fix from Kevin in the branch you are testing with.

http://www.mail-archive.com/linux-omap@vger.kernel.org/msg54927.html
{OMAP: omap_device: fix !CONFIG_SUSPEND case in _noirq handlers}

If you rebase, your branch against 3.1-rc6, you should already
have this fix. Commit {126caf1376e7}

Regards
Santosh