From: Pavel Machek <pavel@ucw.cz>
To: Raul E Rangel <rrangel@chromium.org>
Cc: linux-input@vger.kernel.org, dmitry.torokhov@gmail.com,
Shirish.S@amd.com, Andy Shevchenko <andy@infradead.org>,
Dan Murphy <dmurphy@ti.com>, Darren Hart <dvhart@infradead.org>,
Jacek Anaszewski <jacek.anaszewski@gmail.com>,
"Lee, Chun-Yi" <jlee@suse.com>, Rajat Jain <rajatja@google.com>,
Stephen Boyd <swboyd@chromium.org>,
linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org,
platform-driver-x86@vger.kernel.org
Subject: Re: [PATCH 1/2] Input: i8042 - Prevent intermixing i8042 commands
Date: Sat, 29 Aug 2020 09:47:58 +0200 [thread overview]
Message-ID: <20200829074758.GA16838@amd> (raw)
In-Reply-To: <20200827135205.1.I6981f9a9f0c12e60f8038f3b574184f8ffc1b9b5@changeid>
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On Thu 2020-08-27 13:52:22, Raul E Rangel wrote:
> The i8042_mutex must be held by writers of the AUX and KBD ports, as
> well as users of i8042_command. There were a lot of users of
> i8042_command that were not calling i8042_lock_chip/i8042_unlock_chip.
> This resulted in i8042_commands being issues in between PS/2
> transactions.
>
> This change moves the mutex lock into i8042_command and removes the
> burden of locking the mutex from the callers.
>
> It is expected that the i8042_mutex is locked before calling
> i8042_aux_write or i8042_kbd_write. This is currently done by the PS/2
> layer via ps2_begin_command and ps2_end_command. Other modules
> (serio_raw) do not currently lock the mutex, so there is still a
> possibility for intermixed commands.
> @@ -343,10 +330,14 @@ int i8042_command(unsigned char *param, int command)
> unsigned long flags;
> int retval;
>
> + mutex_lock(&i8042_mutex);
> +
> spin_lock_irqsave(&i8042_lock, flags);
> retval = __i8042_command(param, command);
> spin_unlock_irqrestore(&i8042_lock, flags);
>
> + mutex_unlock(&i8042_mutex);
> +
> return retval;
There's something wrong with whitespace here. Checkpatch?
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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next prev parent reply other threads:[~2020-08-29 7:48 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-27 19:52 [PATCH 1/2] Input: i8042 - Prevent intermixing i8042 commands Raul E Rangel
2020-08-27 19:52 ` [PATCH 2/2] Input: i8042 - Lock i8042_mutex before flushing Raul E Rangel
2020-08-27 20:12 ` [PATCH 1/2] Input: i8042 - Prevent intermixing i8042 commands Andy Shevchenko
2020-08-27 20:18 ` Andy Shevchenko
2020-08-27 20:20 ` Raul Rangel
2020-08-29 7:47 ` Pavel Machek [this message]
2020-08-31 13:39 ` Raul Rangel
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