From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Date: Fri, 09 Aug 2013 18:32:12 +0000 Subject: Re: [PATCH v2] tmio_mmc_dma: fix PIO fallback on SDHI Message-Id: <520535AC.6000200@cogentembedded.com> List-Id: References: <201308030233.29446.sergei.shtylyov@cogentembedded.com> In-Reply-To: <201308030233.29446.sergei.shtylyov@cogentembedded.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-mmc@vger.kernel.org, g.liakhovetski@gmx.de, ian@mnementh.co.uk, cjb@laptop.org Cc: linux-sh@vger.kernel.org, max.filippov@cogentembedded.com Hello. On 08/03/2013 02:33 AM, Sergei Shtylyov wrote: > I'm testing SH-Mobile SDHI driver in DMA mode with a new DMA controller using The driver for this controller is using drivers/dma/sh/shdma-base.c framework. > 'bonnie++' and getting DMA error And I suspect some bug/race in shdma-base.c. The S/G request that fails seems to always consist of 32 segments (maximum for shdma-base.c) and it fails like this: hpb-dma-engine hpb-dma-engine: No free link descriptor available which is a message that shdma_add_desc() prints when shdma_get-desc() returns NULL. When I turn on all dev_dbg() calls (via #define DEBUG) in shdma-base.c. the error is *gone*... > Signed-off-by: Sergei Shtylyov > Cc: stable@vger.kernel.org # 3.1+ WBR, Sergei