linux-kernel - Re: Handling <Ctrl-c> like events in 's_power' implementation when we have a GPIO controlling the sensor CE

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <CACRpkdbB2ALMeBZfba7rz+NyNC-z-XfT4wuHLGgxMJ+iFYwomg@mail.gmail.com>
Date:	Wed, 1 Feb 2012 13:29:29 +0100
From:	Linus Walleij <linus.walleij@...aro.org>
To:	Bhupesh SHARMA <bhupesh.sharma@...com>
Cc:	Guennadi Liakhovetski <g.liakhovetski@....de>,
	"linux-media@...r.kernel.org" <linux-media@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Rabin VINCENT <rabin.vincent@...ricsson.com>,
	Linus WALLEIJ <linus.walleij@...ricsson.com>,
	Ben Dooks <ben-linux@...ff.org>
Subject: Re: Handling <Ctrl-c> like events in 's_power' implementation when we
 have a GPIO controlling the sensor CE

On Wed, Feb 1, 2012 at 6:01 AM, Bhupesh SHARMA <bhupesh.sharma@...com> wrote:

> Our board has a I2C controlled camera sensor whose Chip Enable (CE)
> pin is driven via a GPIO. This GPIO is made available by a I2C-to-GPIO
> expander chip (STMPE801, see user manual [1])
(...)
> the I2C controller driver
> (we use the standard SYNOPSYS designware device driver present in mainline,
> see [3]) returns -ERESTARTSYS in response to the write command we had requested
> for putting the sensor to power-off state (as it has received the <ctrl-c> kill
> signal).

So what happens if you go into the I2C driver and replace all things
that look like this:

ret = wait_for_completion_interruptible_timeout(&dev->cmd_complete, HZ);

With this:
ret = wait_for_completion_timeout(&dev->cmd_complete, HZ);

(Non-interruptible.)

This is usually the problem.

Yours,
Linus Walleij
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/