[PATCH 5.14 344/432] mmc: core: Avoid hogging the CPU while polling for busy in the I/O err path
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-09-16 17:52:03
Also in:
lkml
Subsystem:
multimedia card (mmc), secure digital (sd) and sdio subsystem, the rest · Maintainers:
Ulf Hansson, Linus Torvalds
From: Ulf Hansson <redacted> [ Upstream commit 972d5084831dc9ae30f1a4b66cb4a19fb7ba6f09 ] 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 <redacted> Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com> Link: https://lore.kernel.org/r/20210702134229.357717-2-ulf.hansson@linaro.org (local) Signed-off-by: Sasha Levin <sashal@kernel.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 ce8aed562929..170343411f53 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 973756ed4016..e2c431c0ce5d 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 41ab4f573a31..ae25ffc2e870 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;
--
2.30.2