mmc: core: Avoid hogging the CPU while polling for busy for mmc ioctls

When __mmc_blk_ioctl_cmd() calls card_busy_detect() to verify that the
card's states moves back into transfer state, the polling with CMD13 is
done without any delays in between the commands being sent.

Rather than fixing card_busy_detect() in this regards, let's instead
convert into using the common mmc_poll_for_busy(), which also helps us to
avoid open-coding.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>
Link: https://lore.kernel.org/r/20210702134229.357717-3-ulf.hansson@linaro.org

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index 170343411f5348051261566ff6f3b0db22a4261a..c30d0ab15539b68a6898280ab5952dd4db4f194d 100644 (file)
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -605,7 +605,8 @@ static int __mmc_blk_ioctl_cmd(struct mmc_card *card, struct mmc_blk_data *md,
                 * Ensure RPMB/R1B command has completed by polling CMD13
                 * "Send Status".
                 */
-               err = card_busy_detect(card, MMC_BLK_TIMEOUT_MS, NULL);
+               err = mmc_poll_for_busy(card, MMC_BLK_TIMEOUT_MS, false,
+                                       MMC_BUSY_IO);
        }
 
        return err;