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mmc: rtsx_pci_sdmmc: fix incorrect last byte in R2 response 

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.

Cc: <stable@vger.kernel.org> # v3.8+
Fixes: ff984e57d3 ("mmc: Add realtek pcie sdmmc host driver")
Signed-off-by: Roger Tseng <rogerable@realtek.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
Roger Tseng 2014-08-15 14:06:00 +08:00 committed by Ulf Hansson
parent ee9d19d42c
commit d1419d50c1
1 changed files with 7 additions and 0 deletions
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7
drivers/mmc/host/rtsx_pci_sdmmc.c
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@ -412,6 +412,13 @@ 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",