From: Roger Tseng Date: Fri, 15 Aug 2014 06:06:01 +0000 (+0800) Subject: mmc: rtsx_usb_sdmmc: fix incorrect last byte in R2 response X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=6f67cc6fd1cf339a0f19b9d4a998ec3c0123b1b6;p=deliverable%2Flinux.git mmc: rtsx_usb_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: # v3.16+ Fixes: c7f6558d84af ("mmc: Add realtek USB sdmmc host driver") Signed-off-by: Roger Tseng Signed-off-by: Ulf Hansson --- diff --git a/drivers/mmc/host/rtsx_usb_sdmmc.c b/drivers/mmc/host/rtsx_usb_sdmmc.c index 5d3766e792f0..d9153a7d160d 100644 --- a/drivers/mmc/host/rtsx_usb_sdmmc.c +++ b/drivers/mmc/host/rtsx_usb_sdmmc.c @@ -435,6 +435,13 @@ static void sd_send_cmd_get_rsp(struct rtsx_usb_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",