When sending the sleep command for host drivers supporting
MMC_CAP_WAIT_WHILE_BUSY, we need to confirm that max_busy_timeout is
big enough comparing to the sleep timeout specified from card's
EXT_CSD. If this isn't case, we use a R1 response instead of R1B and
fallback to use a delay instead.
Do note that a max_busy_timeout set to zero by the host, is interpreted
as it can cope with whatever timeout the mmc core provides it with.
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
---
drivers/mmc/core/mmc.c | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 897fdd1..d641590 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1359,6 +1359,7 @@ static int mmc_sleep(struct mmc_host *host)
{
struct mmc_command cmd = {0};
struct mmc_card *card = host->card;
+ unsigned int timeout_ms = DIV_ROUND_UP(card->ext_csd.sa_timeout, 10000);
int err;
if (host->caps2 & MMC_CAP2_NO_SLEEP_CMD)
@@ -1372,7 +1373,19 @@ static int mmc_sleep(struct mmc_host *host)
cmd.arg = card->rca << 16;
cmd.arg |= 1 << 15;
- cmd.flags = MMC_RSP_R1B | MMC_CMD_AC;
+ /*
+ * If the max_busy_timeout of the host is specified, validate it against
+ * the sleep cmd timeout. A failure means we need to prevent the host
+ * from doing hw busy detection, which is done by converting to a R1
+ * response instead of a R1B.
+ */
+ if (host->max_busy_timeout && (timeout_ms > host->max_busy_timeout)) {
+ cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
+ } else {
+ cmd.flags = MMC_RSP_R1B | MMC_CMD_AC;
+ cmd.busy_timeout = timeout_ms;
+ }
+
err = mmc_wait_for_cmd(host, &cmd, 0);
if (err)
return err;
@@ -1383,8 +1396,8 @@ static int mmc_sleep(struct mmc_host *host)
* SEND_STATUS command to poll the status because that command (and most
* others) is invalid while the card sleeps.
*/
- if (!(host->caps & MMC_CAP_WAIT_WHILE_BUSY))
- mmc_delay(DIV_ROUND_UP(card->ext_csd.sa_timeout, 10000));
+ if (!cmd.busy_timeout || !(host->caps & MMC_CAP_WAIT_WHILE_BUSY))
+ mmc_delay(timeout_ms);
return err;
}
--
1.7.9.5
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
