summaryrefslogtreecommitdiff
path: root/drivers/mmc
diff options
context:
space:
mode:
authorUlf Hansson <ulf.hansson@linaro.org>2021-07-02 15:42:29 +0200
committerUlf Hansson <ulf.hansson@linaro.org>2021-08-24 10:15:32 +0200
commit6966e6094c6d594044ef1b740dd827e05881331c (patch)
tree4a9ba8bc0ecd16dac8a1198d1a491b61adcd888d /drivers/mmc
parent468108155b0f89cc08189cc33f9bacfe9da8a125 (diff)
downloadlwn-6966e6094c6d594044ef1b740dd827e05881331c.tar.gz
lwn-6966e6094c6d594044ef1b740dd827e05881331c.zip
mmc: core: Avoid hogging the CPU while polling for busy after I/O writes
When mmc_blk_card_busy() 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 <ulf.hansson@linaro.org> Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com> Link: https://lore.kernel.org/r/20210702134229.357717-4-ulf.hansson@linaro.org
Diffstat (limited to 'drivers/mmc')
-rw-r--r--drivers/mmc/core/block.c69
-rw-r--r--drivers/mmc/core/mmc_ops.c1
2 files changed, 30 insertions, 40 deletions
diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index c30d0ab15539..a9ad9f5fa949 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -98,6 +98,11 @@ static int max_devices;
static DEFINE_IDA(mmc_blk_ida);
static DEFINE_IDA(mmc_rpmb_ida);
+struct mmc_blk_busy_data {
+ struct mmc_card *card;
+ u32 status;
+};
+
/*
* There is one mmc_blk_data per slot.
*/
@@ -417,42 +422,6 @@ static int mmc_blk_ioctl_copy_to_user(struct mmc_ioc_cmd __user *ic_ptr,
return 0;
}
-static int card_busy_detect(struct mmc_card *card, unsigned int timeout_ms,
- u32 *resp_errs)
-{
- unsigned long timeout = jiffies + msecs_to_jiffies(timeout_ms);
- int err = 0;
- u32 status;
-
- do {
- bool done = time_after(jiffies, timeout);
-
- err = __mmc_send_status(card, &status, 5);
- if (err) {
- dev_err(mmc_dev(card->host),
- "error %d requesting status\n", err);
- return err;
- }
-
- /* Accumulate any response error bits seen */
- if (resp_errs)
- *resp_errs |= status;
-
- /*
- * Timeout if the device never becomes ready for data and never
- * leaves the program state.
- */
- if (done) {
- dev_err(mmc_dev(card->host),
- "Card stuck in wrong state! %s status: %#x\n",
- __func__, status);
- return -ETIMEDOUT;
- }
- } while (!mmc_ready_for_data(status));
-
- return err;
-}
-
static int __mmc_blk_ioctl_cmd(struct mmc_card *card, struct mmc_blk_data *md,
struct mmc_blk_ioc_data *idata)
{
@@ -1852,28 +1821,48 @@ static inline bool mmc_blk_rq_error(struct mmc_blk_request *brq)
brq->data.error || brq->cmd.resp[0] & CMD_ERRORS;
}
+static int mmc_blk_busy_cb(void *cb_data, bool *busy)
+{
+ struct mmc_blk_busy_data *data = cb_data;
+ u32 status = 0;
+ int err;
+
+ err = mmc_send_status(data->card, &status);
+ if (err)
+ return err;
+
+ /* Accumulate response error bits. */
+ data->status |= status;
+
+ *busy = !mmc_ready_for_data(status);
+ return 0;
+}
+
static int mmc_blk_card_busy(struct mmc_card *card, struct request *req)
{
struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
- u32 status = 0;
+ struct mmc_blk_busy_data cb_data;
int err;
if (mmc_host_is_spi(card->host) || rq_data_dir(req) == READ)
return 0;
- err = card_busy_detect(card, MMC_BLK_TIMEOUT_MS, &status);
+ cb_data.card = card;
+ cb_data.status = 0;
+ err = __mmc_poll_for_busy(card, MMC_BLK_TIMEOUT_MS, &mmc_blk_busy_cb,
+ &cb_data);
/*
* Do not assume data transferred correctly if there are any error bits
* set.
*/
- if (status & mmc_blk_stop_err_bits(&mqrq->brq)) {
+ if (cb_data.status & mmc_blk_stop_err_bits(&mqrq->brq)) {
mqrq->brq.data.bytes_xfered = 0;
err = err ? err : -EIO;
}
/* Copy the exception bit so it will be seen later on */
- if (mmc_card_mmc(card) && status & R1_EXCEPTION_EVENT)
+ if (mmc_card_mmc(card) && cb_data.status & R1_EXCEPTION_EVENT)
mqrq->brq.cmd.resp[0] |= R1_EXCEPTION_EVENT;
return err;
diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index e2c431c0ce5d..90d213a2203f 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -510,6 +510,7 @@ int __mmc_poll_for_busy(struct mmc_card *card, unsigned int timeout_ms,
return 0;
}
+EXPORT_SYMBOL_GPL(__mmc_poll_for_busy);
int mmc_poll_for_busy(struct mmc_card *card, unsigned int timeout_ms,
bool retry_crc_err, enum mmc_busy_cmd busy_cmd)