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authorRoger Tseng <rogerable@realtek.com>2014-08-15 14:06:00 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-11-14 08:59:46 -0800
commitd2d9b7b9b866f0a4a349e4ce4c2904da86df25fd (patch)
tree9c331f78e6e7fc259f798f2ce3be00409a207afe /drivers/mmc
parent003b4f8c41e8e9a9d735145d4a1e084656028187 (diff)
mmc: rtsx_pci_sdmmc: fix incorrect last byte in R2 response
commit d1419d50c1bf711e9fd27b516a739c86b23f7cf9 upstream. Current code erroneously fill the last byte of R2 response with an undefined value. In addition, the controller actually 'offloads' the last byte (CRC7, end bit) while receiving R2 response and thus it's impossible to get the actual value. This could cause mmc stack to obtain inconsistent CID from the same card after resume and misidentify it as a different card. Fix by assigning dummy CRC and end bit: {7'b0, 1} = 0x1 to the last byte of R2. Fixes: ff984e57d36e ("mmc: Add realtek pcie sdmmc host driver") Signed-off-by: Roger Tseng <rogerable@realtek.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/mmc')
-rw-r--r--drivers/mmc/host/rtsx_pci_sdmmc.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/mmc/host/rtsx_pci_sdmmc.c b/drivers/mmc/host/rtsx_pci_sdmmc.c
index 7e1866175e7b..ca297d741207 100644
--- a/drivers/mmc/host/rtsx_pci_sdmmc.c
+++ b/drivers/mmc/host/rtsx_pci_sdmmc.c
@@ -342,6 +342,13 @@ static void sd_send_cmd_get_rsp(struct realtek_pci_sdmmc *host,
}
if (rsp_type == SD_RSP_TYPE_R2) {
+ /*
+ * The controller offloads the last byte {CRC-7, end bit 1'b1}
+ * of response type R2. Assign dummy CRC, 0, and end bit to the
+ * byte(ptr[16], goes into the LSB of resp[3] later).
+ */
+ ptr[16] = 1;
+
for (i = 0; i < 4; i++) {
cmd->resp[i] = get_unaligned_be32(ptr + 1 + i * 4);
dev_dbg(sdmmc_dev(host), "cmd->resp[%d] = 0x%08x\n",