Commit 972d5084 authored by Ulf Hansson's avatar Ulf Hansson
Browse files

mmc: core: Avoid hogging the CPU while polling for busy in the I/O err path 



When mmc_blk_fix_state() sends a CMD12 to try to move the card into the
transfer state, it calls card_busy_detect() to poll for the card's state
with CMD13. This 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: default avatarUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: default avatarShawn Lin <shawn.lin@rock-chips.com>
Link: https://lore.kernel.org/r/20210702134229.357717-2-ulf.hansson@linaro.org
parent 2b8ac062

drivers/mmc/core/block.c

+1 −1
Original line number Diff line number Diff line
@@ -1636,7 +1636,7 @@ static int mmc_blk_fix_state(struct mmc_card *card, struct request *req) 


	mmc_blk_send_stop(card, timeout);



	err = card_busy_detect(card, timeout, NULL);

	err = mmc_poll_for_busy(card, timeout, false, MMC_BUSY_IO);



	mmc_retune_release(card->host);

drivers/mmc/core/mmc_ops.c

+3 −1
Original line number Diff line number Diff line
@@ -435,7 +435,7 @@ static int mmc_busy_cb(void *cb_data, bool *busy) 
	u32 status = 0;

	int err;



	if (host->ops->card_busy) {

	if (data->busy_cmd != MMC_BUSY_IO && host->ops->card_busy) {

		*busy = host->ops->card_busy(host);

		return 0;

	}
@@ -457,6 +457,7 @@ static int mmc_busy_cb(void *cb_data, bool *busy) 
		break;

	case MMC_BUSY_HPI:

	case MMC_BUSY_EXTR_SINGLE:

	case MMC_BUSY_IO:

		break;

	default:

		err = -EINVAL;
@@ -521,6 +522,7 @@ int mmc_poll_for_busy(struct mmc_card *card, unsigned int timeout_ms, 


	return __mmc_poll_for_busy(card, timeout_ms, &mmc_busy_cb, &cb_data);

}

EXPORT_SYMBOL_GPL(mmc_poll_for_busy);



bool mmc_prepare_busy_cmd(struct mmc_host *host, struct mmc_command *cmd,

			  unsigned int timeout_ms)

drivers/mmc/core/mmc_ops.h

+1 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ enum mmc_busy_cmd { 
	MMC_BUSY_ERASE,

	MMC_BUSY_HPI,

	MMC_BUSY_EXTR_SINGLE,

	MMC_BUSY_IO,

};



struct mmc_host;