From 972d5084831dc9ae30f1a4b66cb4a19fb7ba6f09 Mon Sep 17 00:00:00 2001 From: Ulf Hansson Date: Fri, 2 Jul 2021 15:42:27 +0200 Subject: [PATCH] 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: Ulf Hansson Reviewed-by: Shawn Lin Link: https://lore.kernel.org/r/20210702134229.357717-2-ulf.hansson@linaro.org --- drivers/mmc/core/block.c | 2 +- drivers/mmc/core/mmc_ops.c | 4 +++- drivers/mmc/core/mmc_ops.h | 1 + 3 files changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c index ce8aed5..1703434 100644 --- a/drivers/mmc/core/block.c +++ b/drivers/mmc/core/block.c @@ -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); diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c index 973756e..e2c431c 100644 --- a/drivers/mmc/core/mmc_ops.c +++ b/drivers/mmc/core/mmc_ops.c @@ -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) diff --git a/drivers/mmc/core/mmc_ops.h b/drivers/mmc/core/mmc_ops.h index 41ab4f57..ae25ffc 100644 --- a/drivers/mmc/core/mmc_ops.h +++ b/drivers/mmc/core/mmc_ops.h @@ -15,6 +15,7 @@ enum mmc_busy_cmd { MMC_BUSY_ERASE, MMC_BUSY_HPI, MMC_BUSY_EXTR_SINGLE, + MMC_BUSY_IO, }; struct mmc_host; -- 2.7.4