linux-kernel - Re: Nokia N900 - audio TPA6130A2 problems

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

Date:	Mon, 14 Mar 2016 11:59:13 +0200
From:	Peter Ujfalusi <peter.ujfalusi@...com>
To:	Pali Rohár <pali.rohar@...il.com>,
	Sebastian Reichel <sre@...nel.org>,
	Jarkko Nikula <jarkko.nikula@...mer.com>,
	Tony Lindgren <tony@...mide.com>
CC:	Lars-Peter Clausen <lars@...afoo.de>,
	<linux-kernel@...r.kernel.org>, <linux-omap@...r.kernel.org>,
	Pavel Machek <pavel@....cz>,
	Aaro Koskinen <aaro.koskinen@....fi>,
	Nishanth Menon <nm@...com>,
	Ivaylo Dimitrov <ivo.g.dimitrov.75@...il.com>,
	<merlijn@...zup.org>
Subject: Re: Nokia N900 - audio TPA6130A2 problems

On 2016-03-12 14:42, Pali Rohár wrote:
> Hi Sebastian! Commenting calling lp55xx_reset_device function did not 
> helped. Still getting that error.
> 
> Tony, Peter, Jarkko: can you reproduce this problem? I'm really stucked 
> here... do not know where is problem or how to fix it. What we know that
>  it happens when rebooting from stock Nokia kernel (2.6.28) to upstream.

I'm sorry, but I can not debug my n900 as I rely on it as primary phone
time-to-time.

I would try to disable one by one the drivers for devices on the i2c_2 bus
in the stock kernel and see if this will point to something.
It might worth looking at the driver init codes for the devices we have on
i2c_2 also. Since rebooting to stock kernel does not have issue, it might be
the chip init for at least one of the device might cause the i2c bus lock.
It is also possible that the driver load order is different and we might
need to load one of the drivers before the others?
In the board file (board-rx51-peripherals.c) the tpa is the last entry in
the i2c_board_info, so it is most likely the last one to load among the
drivers for i2c_2 devices. In the dts si4713 and bq24150a is after the
tpa... Try to move the tpa as last one in the dts?

Does the i2c communication breaks with DT _and_ non DT boot?

-- 
Péter