From cfbeb59c7a818a2ec0008914ce479fe5d6f5978b Mon Sep 17 00:00:00 2001 From: Markos Chandras Date: Tue, 12 Mar 2013 10:53:13 +0000 Subject: mmc: dw_mmc: Handle unaligned data submission correctly Commit f9c2a0dc42a6938ff2a80e55ca2bbd1d5581c72e "mmc: dw_mmc: Fix PIO mode with support of highmem" introduced a regression since v3.2 making the mmc_test hang on test #13 with a "Data starvation by host timeout" interrupt. This is because, sg_mapping_iter is used to iterate through the data which spans on multiple pages. The problem is detected on unaligned data submission where the code previously checked for !(sg_next(host->sg)) which is true because we only have a single scatter/gather list which then expands to multiple pages. Therefore, the driver incorrectly assumed that this was the last list item and submitted unaligned data to the mmc device. This overflowed the FIFO on the device before all the data were written to it. The code was fixed to only submit unaligned data when we are handling the last sg_miter item by checking whether we reached the desired data length or not. The patch was tested against mmc_test and all the tests passed. Signed-off-by: Markos Chandras Acked-by: Jaehoon Chung Acked-by: Seungwon Jeon Signed-off-by: Chris Ball --- drivers/mmc/host/dw_mmc.c | 33 ++++++++++++++++++++++++--------- 1 file changed, 24 insertions(+), 9 deletions(-) (limited to 'drivers/mmc/host') diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index a23b262f9cd..a4438205954 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -1199,12 +1199,15 @@ static void dw_mci_pull_final_bytes(struct dw_mci *host, void *buf, int cnt) static void dw_mci_push_data16(struct dw_mci *host, void *buf, int cnt) { + struct mmc_data *data = host->data; + int init_cnt = cnt; + /* try and push anything in the part_buf */ if (unlikely(host->part_buf_count)) { int len = dw_mci_push_part_bytes(host, buf, cnt); buf += len; cnt -= len; - if (!sg_next(host->sg) || host->part_buf_count == 2) { + if (host->part_buf_count == 2) { mci_writew(host, DATA(host->data_offset), host->part_buf16); host->part_buf_count = 0; @@ -1237,9 +1240,11 @@ static void dw_mci_push_data16(struct dw_mci *host, void *buf, int cnt) /* put anything remaining in the part_buf */ if (cnt) { dw_mci_set_part_bytes(host, buf, cnt); - if (!sg_next(host->sg)) + /* Push data if we have reached the expected data length */ + if ((data->bytes_xfered + init_cnt) == + (data->blksz * data->blocks)) mci_writew(host, DATA(host->data_offset), - host->part_buf16); + host->part_buf16); } } @@ -1277,12 +1282,15 @@ static void dw_mci_pull_data16(struct dw_mci *host, void *buf, int cnt) static void dw_mci_push_data32(struct dw_mci *host, void *buf, int cnt) { + struct mmc_data *data = host->data; + int init_cnt = cnt; + /* try and push anything in the part_buf */ if (unlikely(host->part_buf_count)) { int len = dw_mci_push_part_bytes(host, buf, cnt); buf += len; cnt -= len; - if (!sg_next(host->sg) || host->part_buf_count == 4) { + if (host->part_buf_count == 4) { mci_writel(host, DATA(host->data_offset), host->part_buf32); host->part_buf_count = 0; @@ -1315,9 +1323,11 @@ static void dw_mci_push_data32(struct dw_mci *host, void *buf, int cnt) /* put anything remaining in the part_buf */ if (cnt) { dw_mci_set_part_bytes(host, buf, cnt); - if (!sg_next(host->sg)) + /* Push data if we have reached the expected data length */ + if ((data->bytes_xfered + init_cnt) == + (data->blksz * data->blocks)) mci_writel(host, DATA(host->data_offset), - host->part_buf32); + host->part_buf32); } } @@ -1355,12 +1365,15 @@ static void dw_mci_pull_data32(struct dw_mci *host, void *buf, int cnt) static void dw_mci_push_data64(struct dw_mci *host, void *buf, int cnt) { + struct mmc_data *data = host->data; + int init_cnt = cnt; + /* try and push anything in the part_buf */ if (unlikely(host->part_buf_count)) { int len = dw_mci_push_part_bytes(host, buf, cnt); buf += len; cnt -= len; - if (!sg_next(host->sg) || host->part_buf_count == 8) { + if (host->part_buf_count == 8) { mci_writew(host, DATA(host->data_offset), host->part_buf); host->part_buf_count = 0; @@ -1393,9 +1406,11 @@ static void dw_mci_push_data64(struct dw_mci *host, void *buf, int cnt) /* put anything remaining in the part_buf */ if (cnt) { dw_mci_set_part_bytes(host, buf, cnt); - if (!sg_next(host->sg)) + /* Push data if we have reached the expected data length */ + if ((data->bytes_xfered + init_cnt) == + (data->blksz * data->blocks)) mci_writeq(host, DATA(host->data_offset), - host->part_buf); + host->part_buf); } } -- cgit v1.2.3