Re: [PATCH v3] pinctrl: pinmux: Don't free pins requested by otherdevices in pinmux_disable_setting.

From: Stephen Warren
Date: Tue Aug 13 2013 - 11:46:33 EST


On 08/12/2013 10:54 PM, Sonic Zhang 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.

> diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c

> @@ -480,15 +480,17 @@ void pinmux_disable_setting(struct pinctrl_setting const *setting)
> dev_warn(pctldev->dev,
> "could not get pin desc for pin %d\n",
> pins[i]);
> + /* And release the pin */
> + pin_free(pctldev, pins[i], NULL);

This change doesn't seem useful. The 2 lines right above the patch
context are:

desc = pin_desc_get(pctldev, pins[i]);
if (desc == NULL) {

... and the first thing pin_free() does it call pin_desc_get() again.
So, pin_free() is simply going to fail and print another error.

The rest of the patch looks good.

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