From a9003dc641cf881992897585392567811652de09 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Fri, 4 Nov 2016 16:18:08 +0100 Subject: [PATCH] mmc: Retry the switch command Some eMMC will fail at the first switch, but would succeed in a subsequent one. Make sure we try several times to cover those cases. The number of retries (and the behaviour) is currently what is being used in Linux. Signed-off-by: Maxime Ripard Reviewed-by: Hans de Goede Reviewed-by: Tom Rini --- drivers/mmc/mmc.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index 4380c7c195..d6b7e4f510 100644 --- a/drivers/mmc/mmc.c +++ b/drivers/mmc/mmc.c @@ -494,6 +494,7 @@ int mmc_switch(struct mmc *mmc, u8 set, u8 index, u8 value) { struct mmc_cmd cmd; int timeout = 1000; + int retries = 3; int ret; cmd.cmdidx = MMC_CMD_SWITCH; @@ -502,11 +503,17 @@ int mmc_switch(struct mmc *mmc, u8 set, u8 index, u8 value) (index << 16) | (value << 8); - ret = mmc_send_cmd(mmc, &cmd, NULL); + while (retries > 0) { + ret = mmc_send_cmd(mmc, &cmd, NULL); - /* Waiting for the ready status */ - if (!ret) - ret = mmc_send_status(mmc, timeout); + /* Waiting for the ready status */ + if (!ret) { + ret = mmc_send_status(mmc, timeout); + return ret; + } + + retries--; + } return ret; -- 2.39.2