From: Stephen Warren <swarren@wwwdotorg.org>
To: Richard Genoud <richard.genoud@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>,
Axel Lin <axel.lin@ingics.com>,
Stephen Warren <swarren@nvidia.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] BUG: pinmux: forbid mux_usecount to be set at UINT_MAX
Date: Wed, 20 Mar 2013 10:14:00 -0600 [thread overview]
Message-ID: <5149E048.6030305@wwwdotorg.org> (raw)
In-Reply-To: <1363779113-8776-2-git-send-email-richard.genoud@gmail.com>
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--;
next prev parent reply other threads:[~2013-03-20 16:14 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-20 11:31 [PATCH] BUG: pinmux: release only taken pins on error Richard Genoud
2013-03-20 11:31 ` [PATCH] BUG: pinmux: forbid mux_usecount to be set at UINT_MAX Richard Genoud
2013-03-20 16:14 ` Stephen Warren [this message]
2013-03-20 16:59 ` Richard Genoud
2013-03-20 17:08 ` Stephen Warren
2013-03-21 11:21 ` Richard Genoud
2013-03-21 17:33 ` Stephen Warren
2013-03-21 18:28 ` Linus Walleij
2013-03-20 11:31 ` [PATCH] BUG: [RFC] pinctrl: pins are freed 2 times in pinctrl_bind_pins Richard Genoud
2013-03-20 16:23 ` Stephen Warren
2013-03-21 11:31 ` Richard Genoud
2013-03-20 13:21 ` [PATCH] BUG: pinmux: release only taken pins on error Axel Lin
2013-03-20 14:19 ` Richard Genoud
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