[PATCH 3.16 42/63] mmc: mmc: fix switch timeout issue caused by jiffies precision

From: Ben Hutchings
Date: Wed Jan 08 2020 - 14:47:38 EST


3.16.81-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Chaotian Jing <chaotian.jing@xxxxxxxxxxxx>

commit 987aa5f8059613bf85cbb6f64ffbd34f5cb7a9d1 upstream.

with CONFIG_HZ=100, the precision of jiffies is 10ms, and the
generic_cmd6_time of some card is also 10ms. then, may be current
time is only 5ms, but already timed out caused by jiffies precision.

Signed-off-by: Chaotian Jing <chaotian.jing@xxxxxxxxxxxx>
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/mmc/core/mmc_ops.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -470,7 +470,7 @@ int __mmc_switch(struct mmc_card *card,
timeout_ms = MMC_OPS_TIMEOUT_MS;

/* Must check status to be sure of no errors. */
- timeout = jiffies + msecs_to_jiffies(timeout_ms);
+ timeout = jiffies + msecs_to_jiffies(timeout_ms) + 1;
do {
if (send_status) {
err = __mmc_send_status(card, &status, ignore_crc);