[PATCH 3/3] mmc: core: Default to generic_cmd6_time as timeout in __mmc_switch()

Ulf Hansson
2020-01-22T14:28:01Z

All callers of __mmc_switch() should now be specifying a valid timeout for
the CMD6 command. However, to sure let's print a warning and default to use
the generic_cmd6_time in case the provided timeout_ms argument is zero.

In this context, let's also simplify some of corresponding code and clarify
some related comments.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
drivers/mmc/core/mmc_ops.c | 25 +++++++++++--------------
1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index 1966abcbc7c0..da425ee2d9bf 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -460,10 +460,6 @@ static int mmc_poll_for_busy(struct mmc_card *card, unsigned int timeout_ms,
bool expired = false;
bool busy = false;

- /* We have an unspecified cmd timeout, use the fallback value. */
- if (!timeout_ms)
- timeout_ms = MMC_OPS_TIMEOUT_MS;
-
/*
* In cases when not allowed to poll by using CMD13 or because we aren't
* capable of polling by using ->card_busy(), then rely on waiting the
@@ -536,14 +532,19 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,

mmc_retune_hold(host);

+ if (!timeout_ms) {
+ pr_warn("%s: unspecified timeout for CMD6 - use generic\n",
+ mmc_hostname(host));
+ timeout_ms = card->ext_csd.generic_cmd6_time;
+ }
+
/*
- * If the cmd timeout and the max_busy_timeout of the host are both
- * specified, let's validate them. 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 the max_busy_timeout of the host is specified, make sure it's
+ * enough to fit the used timeout_ms. In case it's not, let's instruct
+ * the host to avoid HW busy detection, by converting to a R1 response
+ * instead of a R1B.
*/
- if (timeout_ms && host->max_busy_timeout &&
- (timeout_ms > host->max_busy_timeout))
+ if (host->max_busy_timeout && (timeout_ms > host->max_busy_timeout))
use_r1b_resp = false;

cmd.opcode = MMC_SWITCH;
@@ -554,10 +555,6 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
cmd.flags = MMC_CMD_AC;
if (use_r1b_resp) {
cmd.flags |= MMC_RSP_SPI_R1B | MMC_RSP_R1B;
- /*
- * A busy_timeout of zero means the host can decide to use
- * whatever value it finds suitable.
- */
cmd.busy_timeout = timeout_ms;
} else {
cmd.flags |= MMC_RSP_SPI_R1 | MMC_RSP_R1;
--
2.17.1