From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Ball Subject: Re: [PATCH v2] mmc: tmio: Don't access hardware registers after stopping clocks Date: Wed, 20 Jun 2012 02:22:19 -0400 Message-ID: <87fw9q4i5g.fsf@octavius.laptop.org> References: <1339536575-6578-1-git-send-email-laurent.pinchart@ideasonboard.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: (Guennadi Liakhovetski's message of "Wed, 13 Jun 2012 15:27:35 +0200 (CEST)") Sender: linux-sh-owner@vger.kernel.org To: Guennadi Liakhovetski Cc: Laurent Pinchart , linux-mmc@vger.kernel.org, linux-sh@vger.kernel.org List-Id: linux-mmc@vger.kernel.org Hi, On Wed, Jun 13 2012, Guennadi Liakhovetski wrote: > On Tue, 12 Jun 2012, Laurent Pinchart wrote: > >> The tmio_mmc_set_ios() function configures the MMC power, clock and bus >> width. When the mmc core requests the driver to power off the card, we >> inform runtime PM, that the controller can be suspended. This can lead >> to the MSTP clock being turned off. >> >> Writing to any 16-bit hardware registers with the MSTP clock off leads >> to timeouts and errors being printed to the kernel log. This can occur >> both when stopping the MMC clock and when configuring the bus width. >> >> To fix this, stop the MMC clock before calling put_runtime_pm(), and >> skip bus width configuration when power is off. >> >> Signed-off-by: Laurent Pinchart > > Acked-by: Guennadi Liakhovetski Thanks, pushed to mmc-next for 3.6. - Chris. -- Chris Ball One Laptop Per Child