From patchwork Wed Jun 29 08:30:47 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Hogan X-Patchwork-Id: 927542 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.4) with ESMTP id p5T8UrVg011749 for ; Wed, 29 Jun 2011 08:30:53 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753947Ab1F2Iav (ORCPT ); Wed, 29 Jun 2011 04:30:51 -0400 Received: from multi.imgtec.com ([194.200.65.239]:62066 "EHLO multi.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752497Ab1F2Iau (ORCPT ); Wed, 29 Jun 2011 04:30:50 -0400 Message-ID: <4E0AE2B7.3020006@imgtec.com> Date: Wed, 29 Jun 2011 09:30:47 +0100 From: James Hogan User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.15) Gecko/20101027 Fedora/3.0.10-1.fc12 Thunderbird/3.0.10 MIME-Version: 1.0 To: James Hogan CC: Chris Ball , Will , Jaehoon Chung , Kyungmin Park , linux-mmc , linux-kernel Subject: [PATCH 4/4] mmc: dw_mmc: reset FIFO after an error References: <4E0AE1FC.3070201@imgtec.com> In-Reply-To: <4E0AE1FC.3070201@imgtec.com> X-OriginalArrivalTime: 29 Jun 2011 08:30:48.0103 (UTC) FILETIME=[D8D76370:01CC3636] X-SEF-Processed: 7_3_0_01158__2011_06_29_09_30_48 Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Wed, 29 Jun 2011 08:30:55 +0000 (UTC) If an error occurs mid way through a transaction (such as a missing CRC status response after the 2nd block written out of 3), then the FIFO may still contain data which will interfere with the next transaction. Therefore after an error has been detected, reset the fifo using the CTRL register. Signed-off-by: James Hogan --- drivers/mmc/host/dw_mmc.c | 12 +++++++++++- 1 files changed, 11 insertions(+), 1 deletions(-) diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index 0dac397..0c839d3 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -849,7 +849,7 @@ static void dw_mci_tasklet_func(unsigned long priv) struct mmc_command *cmd; enum dw_mci_state state; enum dw_mci_state prev_state; - u32 status; + u32 status, ctrl; spin_lock(&host->lock); @@ -929,6 +929,16 @@ static void dw_mci_tasklet_func(unsigned long priv) status); data->error = -EIO; } + /* + * After an error, there may be data lingering + * in the FIFO, so reset it - doing so + * generates a block interrupt, hence setting + * the scatter-gather pointer to NULL. + */ + host->sg = NULL; + ctrl = mci_readl(host, CTRL); + ctrl |= SDMMC_CTRL_FIFO_RESET; + mci_writel(host, CTRL, ctrl); } else { data->bytes_xfered = data->blocks * data->blksz; data->error = 0;