From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Ujfalusi Subject: Re: Nokia N900 - audio TPA6130A2 problems Date: Tue, 4 Aug 2015 10:02:39 +0300 Message-ID: <55C0638F.30000@ti.com> References: <201507251228.27128@pali> <201508011218.45076@pali> <55BFACE4.1010100@bitmer.com> <201508032017.45654@pali> <55BFB77C.6000208@bitmer.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <55BFB77C.6000208@bitmer.com> Sender: linux-kernel-owner@vger.kernel.org To: Jarkko Nikula , =?UTF-8?Q?Pali_Roh=c3=a1r?= Cc: Lars-Peter Clausen , linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, Pavel Machek , Sebastian Reichel , Aaro Koskinen , Tony Lindgren , Nishanth Menon , Ivaylo Dimitrov List-Id: linux-omap@vger.kernel.org On 08/03/2015 09:48 PM, Jarkko Nikula wrote: > It is well possible that some regression got introduced to TPA6130A2 = I2C > communication over the years without nobody than you now notices. We > used to do QA back in Meego N900 days but that was pre 3.x kernels. No major changes has been done to the tpa driver during the past years.= =2E. I wanted to do some updates, like moving it to regmap, but as you said, n= 900 is the only user (and n9) and I do not feel comfortable to hack on a devic= e where I do not have serial console... And I'm using the n900 time to time als= o. >> So maybe something similar? Kernel expects that some PM or regulator= =20 >> parts are initialized, but they are only sometimes? Just speculation= =2E.. >> > I'm thinking the same. I could figure SCL could be stuck low if TPA o= r > some other chip connected to the same I2C bus is without power and is > pulling I2C signals down. What would happen with the SCL stuck on i2c.2 bus if you remove the tpa= driver from the kernel? If you remove the other drivers for the devices on i2c= =2E2? --=20 P=C3=A9ter