From patchwork Wed Mar 20 09:32:26 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ludovic Desroches X-Patchwork-Id: 2306371 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork2.kernel.org (Postfix) with ESMTP id E2D7ADF24C for ; Wed, 20 Mar 2013 09:36:17 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UIFO2-0004Se-MK; Wed, 20 Mar 2013 09:32:46 +0000 Received: from eusmtp01.atmel.com ([212.144.249.242]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UIFNy-0004FF-QY for linux-arm-kernel@lists.infradead.org; Wed, 20 Mar 2013 09:32:43 +0000 Received: from ibiza.corp.atmel.com (10.161.101.13) by eusmtp01.atmel.com (10.161.101.30) with Microsoft SMTP Server id 14.2.318.4; Wed, 20 Mar 2013 10:32:34 +0100 From: To: , Subject: [PATCH] mmc: atmel-mci: pio hang on block errors Date: Wed, 20 Mar 2013 10:32:26 +0100 Message-ID: <1363771946-8931-1-git-send-email-ludovic.desroches@atmel.com> X-Mailer: git-send-email 1.7.11.3 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130320_053243_093597_6C79D6C6 X-CRM114-Status: GOOD ( 10.71 ) X-Spam-Score: -4.4 (----) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-4.4 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_PASS SPF: sender matches SPF record -2.5 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: terry@beam.ltd.uk, ludovic.desroches@atmel.com, nicolas.ferre@atmel.com X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org From: Terry Barnaby The driver is doing, by default, multi-block reads. When a block error occurs card/block.c instigates a single block read: "mmcblk0: retrying using single block read". It leaves the sg chain intact and just changes the length attribute for the first sg entry and the overall sg_len parameter. When atmci_read_data_pio is called to read the single block of data it ignores the sg_len and expects to read more than 512 bytes as it sees there are multiple items in the sg list. No more data comes as the controller has only been commanded to get one block. Signed-off-by: Terry Barnaby Acked-by: Ludovic Desroches Cc: stable # 3.2+ --- drivers/mmc/host/atmel-mci.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c index 0932024..d98e68e 100644 --- a/drivers/mmc/host/atmel-mci.c +++ b/drivers/mmc/host/atmel-mci.c @@ -163,6 +163,7 @@ struct atmel_mci { void __iomem *regs; struct scatterlist *sg; + unsigned int sg_len; unsigned int pio_offset; struct atmel_mci_slot *cur_slot; @@ -751,6 +752,7 @@ static u32 atmci_prepare_data(struct atmel_mci *host, struct mmc_data *data) data->error = -EINPROGRESS; host->sg = data->sg; + host->sg_len = data->sg_len; host->data = data; host->data_chan = NULL; @@ -1573,7 +1575,8 @@ static void atmci_read_data_pio(struct atmel_mci *host) if (offset == sg->length) { flush_dcache_page(sg_page(sg)); host->sg = sg = sg_next(sg); - if (!sg) + host->sg_len--; + if (!sg || !host->sg_len) goto done; offset = 0; @@ -1586,7 +1589,8 @@ static void atmci_read_data_pio(struct atmel_mci *host) flush_dcache_page(sg_page(sg)); host->sg = sg = sg_next(sg); - if (!sg) + host->sg_len--; + if (!sg || !host->sg_len) goto done; offset = 4 - remaining; @@ -1640,7 +1644,8 @@ static void atmci_write_data_pio(struct atmel_mci *host) nbytes += 4; if (offset == sg->length) { host->sg = sg = sg_next(sg); - if (!sg) + host->sg_len--; + if (!sg || !host->sg_len) goto done; offset = 0; @@ -1654,7 +1659,8 @@ static void atmci_write_data_pio(struct atmel_mci *host) nbytes += remaining; host->sg = sg = sg_next(sg); - if (!sg) { + host->sg_len--; + if (!sg || !host->sg_len) { atmci_writel(host, ATMCI_TDR, value); goto done; }