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SubjectRe: [PATCH] BUG: pinmux: forbid mux_usecount to be set at UINT_MAX
On 03/20/2013 05:31 AM, Richard Genoud wrote:
> If pin_free is called on a pin already freed, mux_usecount is set to
> UINT_MAX which is really a bad idea.
> This will silently ignore a double call to pin_free

Shouldn't we WARN_ON(this case)?

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

> if (!gpio_range) {
> - desc->mux_usecount--;
> - if (desc->mux_usecount)
> + if (1 == desc->mux_usecount)
> + desc->mux_usecount = 0;
> + else
> return NULL;

What if desc-mux_usecount was 2; this patch prevents the use-count from
being decremented to 1 in this case. Shouldn't this be:

if (!gpio_range) {
+ if (WARN_ON(!desc->mux_usecount))
+ return NULL;
desc->mux_usecount--;



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