mmc: core: Respect host's max_busy_timeout when sending sleep cmd
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@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 6b7ccef..1ab5f3a 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1358,6 +1358,7 @@
{
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;
err = mmc_deselect_cards(host);
@@ -1368,7 +1369,19 @@
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;
@@ -1379,8 +1392,8 @@
* 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;
}
