From bdbc5d0c60f3e9de3eeccf1c1a18bdc11dca62cc Mon Sep 17 00:00:00 2001 From: Terry Barnaby Date: Mon, 8 Apr 2013 12:05:47 -0400 Subject: [PATCH] mmc: atmel-mci: pio hang on block errors 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+ Signed-off-by: Chris Ball --- 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 10f8b7358e57..e75774f72606 100644 --- 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 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; @@ -1826,7 +1828,8 @@ 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; @@ -1839,7 +1842,8 @@ 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; @@ -1890,7 +1894,8 @@ 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; @@ -1904,7 +1909,8 @@ 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; } -- 2.39.5