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

From: Linus Walleij
Date: Wed Aug 14 2013 - 11:54:38 EST

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.

Linus Walleij
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