From 5d3f6ef04d65dda92a3573841a7215fb05c347de Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Tue, 22 Sep 2015 17:30:25 +0200 Subject: mmc: Wait for card_busy before starting sdio requests Some sdio wifi chips will not work properly if we try to start new sdio-rw requests while the device is signalling that it is busy. Signed-off-by: Hans de Goede Signed-off-by: Ulf Hansson --- drivers/mmc/core/core.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'drivers') diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 2092a89dcf76..21cda23b247c 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -206,6 +206,23 @@ static void __mmc_start_request(struct mmc_host *host, struct mmc_request *mrq) return; } + /* + * For sdio rw commands we must wait for card busy otherwise some + * sdio devices won't work properly. + */ + if (mmc_is_io_op(mrq->cmd->opcode) && host->ops->card_busy) { + int tries = 500; /* Wait aprox 500ms at maximum */ + + while (host->ops->card_busy(host) && --tries) + mmc_delay(1); + + if (tries == 0) { + mrq->cmd->error = -EBUSY; + mmc_request_done(host, mrq); + return; + } + } + host->ops->request(host, mrq); } -- cgit v1.2.3