Re: [PATCH v4] pinctrl: pinmux: Don't free pins requested by otherdevices in pinmux_disable_setting.

From: Stephen Warren
Date: Wed Aug 14 2013 - 12:22:07 EST


On 08/14/2013 09:54 AM, Linus Walleij wrote:
> On Wed, Aug 14, 2013 at 7:26 AM, Sonic Zhang <sonic.adi@xxxxxxxxx> wrote:
>
>> From: Sonic Zhang <sonic.zhang@xxxxxxxxxx>
>>
>> One peripheral may share part of its pins with the 2nd
>> peripheral and the other pins with the 3rd. If it requests all pins
>> when part of them has already be requested and owned by the 2nd
>> peripheral, this request fails and pinmux_disable_setting() is called.
>> The pinmux_disable_setting() frees all pins of the first peripheral
>> without checking if the pin is owned by itself or the 2nd, which
>> results in the malfunction of the 2nd peripheral driver.
>>
>> Signed-off-by: Sonic Zhang <sonic.zhang@xxxxxxxxxx>
>
> Hm it makes some sense so patch applied.
>
> That said I think we currently have drivers where a pin group
> mapped to a certain function in a certain setting *usually*
> don't overlap with pins in another group used with another
> function, and having it so seems racy, i.e. it will be some
> first-come-first-serve effect.
>
> I will add a warning print.

Surely there's a warning print already when the enable_setting() fails,
so we don't need to do any more warning prints when the free_setting()
cleans up after that?

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