From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Likely Subject: Re: [PATCH V2] mxs: spi: clear XFER_COUNT in ctrl0 field in DMA descriptor Date: Tue, 05 Feb 2013 12:45:35 +0000 Message-ID: <20130205124535.D59043E0E27@localhost> References: <1356500931-31861-1-git-send-email-juha.lumme@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Marek Vasut , Fabio Estevam , Juha Lumme , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Shawn Guo To: Juha Lumme , spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Return-path: In-Reply-To: <1356500931-31861-1-git-send-email-juha.lumme-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: spi-devel-general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-spi.vger.kernel.org On Wed, 26 Dec 2012 14:48:51 +0900, Juha Lumme wrote: > On MX23 the XFER_COUNT part in ctrl0 field in DMA descriptor was improperly > OR'd during the construction of DMA descriptor chain, instead of being > freshly set. > Because of that too many bytes were being expected from SPI during the last > DMA cycle. > This caused a timeout (SSP_TIMEOUT) to happen in the processing of the last > DMA descriptor, and thus reads and writes were failing. > This is a fix for the problem, by clearing XFER_COUNT bytes in ctrl0 before > setting the new XFER_COUNT for DMA descriptor. > > Cc: Marek Vasut > Cc: Fabio Estevam > Cc: Shawn Guo Applied, thanks. g. ------------------------------------------------------------------------------ Free Next-Gen Firewall Hardware Offer Buy your Sophos next-gen firewall before the end March 2013 and get the hardware for free! Learn more. http://p.sf.net/sfu/sophos-d2d-feb