Messages in this thread | | | From | Richard Genoud <> | Date | Wed, 20 Mar 2013 17:59:46 +0100 | Subject | Re: [PATCH] BUG: pinmux: forbid mux_usecount to be set at UINT_MAX |
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2013/3/20 Stephen Warren <swarren@wwwdotorg.org>: > 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)? yes indeed, it may be better to issue a big warning because AFAIK that's not normal.
> >> 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--; > Well, I'm not very familiar with this code, but can mux_usecount be higher than 1 ?
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