This is a note to let you know that I've just added the patch titled mmc: atmel-mci: pio hang on block errors to the 3.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mmc-atmel-mci-pio-hang-on-block-errors.patch and it can be found in the queue-3.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From bdbc5d0c60f3e9de3eeccf1c1a18bdc11dca62cc Mon Sep 17 00:00:00 2001 From: Terry Barnaby <terry@xxxxxxxxxxx> Date: Mon, 8 Apr 2013 12:05:47 -0400 Subject: mmc: atmel-mci: pio hang on block errors From: Terry Barnaby <terry@xxxxxxxxxxx> commit bdbc5d0c60f3e9de3eeccf1c1a18bdc11dca62cc upstream. 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 <terry@xxxxxxxxxxx> Acked-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxx> Signed-off-by: Chris Ball <cjb@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/mmc/host/atmel-mci.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) --- a/drivers/mmc/host/atmel-mci.c +++ b/drivers/mmc/host/atmel-mci.c @@ -178,6 +178,7 @@ struct atmel_mci { void __iomem *regs; struct scatterlist *sg; + unsigned int sg_len; unsigned int pio_offset; unsigned int *buffer; unsigned int buf_size; @@ -892,6 +893,7 @@ static u32 atmci_prepare_data(struct atm data->error = -EINPROGRESS; host->sg = data->sg; + host->sg_len = data->sg_len; host->data = data; host->data_chan = NULL; @@ -1826,7 +1828,8 @@ static void atmci_read_data_pio(struct a 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; @@ -1839,7 +1842,8 @@ static void atmci_read_data_pio(struct a 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; @@ -1890,7 +1894,8 @@ static void atmci_write_data_pio(struct 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; @@ -1904,7 +1909,8 @@ static void atmci_write_data_pio(struct 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; } Patches currently in stable-queue which might be from terry@xxxxxxxxxxx are queue-3.8/mmc-atmel-mci-pio-hang-on-block-errors.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html