Hi On 2017/3/19 8:45, Bean Huo (beanhuo) wrote:
This patch fixes the issue that mmc_blk_issue_rq still flushes cache when eMMC cache has already been off through user space tool, such as mmc-utils.
I did a quick test and see the case you refer to, so Tested-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx> Reviewed-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
The reason is that card->ext_csd.cache_ctrl isn't reset. Signed-off-by: beanhuo <beanhuo@xxxxxxxxxx> --- drivers/mmc/core/block.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c index 1621fa0..fb3635ac 100644 --- a/drivers/mmc/core/block.c +++ b/drivers/mmc/core/block.c @@ -64,6 +64,7 @@ MODULE_ALIAS("mmc:block"); #define MMC_BLK_TIMEOUT_MS (10 * 60 * 1000) /* 10 minute timeout */ #define MMC_SANITIZE_REQ_TIMEOUT 240000 #define MMC_EXTRACT_INDEX_FROM_ARG(x) ((x & 0x00FF0000) >> 16) +#define MMC_EXTRACT_VALUE_FROM_ARG(x) ((x & 0x0000FF00) >> 8) #define mmc_req_rel_wr(req) ((req->cmd_flags & REQ_FUA) && \ (rq_data_dir(req) == WRITE)) @@ -535,6 +536,14 @@ static int __mmc_blk_ioctl_cmd(struct mmc_card *card, struct mmc_blk_data *md, return data.error; } + if ((MMC_EXTRACT_INDEX_FROM_ARG(cmd.arg) == EXT_CSD_CACHE_CTRL) && + (cmd.opcode == MMC_SWITCH) && (card->ext_csd.cache_size > 0)) { + if (MMC_EXTRACT_VALUE_FROM_ARG(cmd.arg) & 1) + card->ext_csd.cache_ctrl = 1; + else + card->ext_csd.cache_ctrl = 0; + } + /* * According to the SD specs, some commands require a delay after * issuing the command.
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