From mboxrd@z Thu Jan  1 00:00:00 1970
From: santosh.shilimkar@ti.com (Santosh Shilimkar)
Date: Wed, 24 Oct 2012 20:08:52 +0530
Subject: [PATCH] gpio/omap: fix off-mode bug: clear debounce clock enable
 mask on disable
In-Reply-To: <87pq4854wu.fsf@deeprootsystems.com>
References: <1351015771-6308-1-git-send-email-khilman@deeprootsystems.com>
 <CANOLnOOUHJg5W9VbHhnK8ta+Bys_oMpSz9M5jQ0xCeOB1gxtdg@mail.gmail.com>
 <87pq4854wu.fsf@deeprootsystems.com>
Message-ID: <5087FD7C.1000006@ti.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Wednesday 24 October 2012 07:49 PM, Kevin Hilman wrote:
> Grazvydas Ignotas <notasas@gmail.com> writes:
>
>> On Tue, Oct 23, 2012 at 9:09 PM, Kevin Hilman
>> <khilman@deeprootsystems.com> wrote:
>>> From: Kevin Hilman <khilman@ti.com>
>>>
>>> When debounce clocks are disabled, ensure that the banks
>>> dbck_enable_mask is cleared also.  Otherwise, context restore on
>>> subsequent off-mode transition will restore previous value from the
>>> shadow copies (bank->context.debounce*) leading to mismatch state
>>> between driver state and hardware state.
>>
>> This doesn't look right to me, aren't you effectively disabling
>> debounce forever here? _gpio_dbck_disable is called from
>> omap_gpio_runtime_suspend() and nothing will ever restore
>> dbck_enable_mask back to what it was set by _set_gpio_debounce and
>> debounce functionality is lost.
>
> Yes, you're right.   Good catch.
>
> I need a fix that's more targetted to the free/reset path.
>
Right. Just clearing the debounce mask in omap_gpio_free()
should do the trick.

Regards
Santosh