[PATCH 2/3] mmc: Wait for card_busy before starting sdio requests
From: Hans de Goede <hidden>
Date: 2015-09-22 15:30:25
Also in:
linux-mmc
Subsystem:
multimedia card (mmc), secure digital (sd) and sdio subsystem, the rest · Maintainers:
Ulf Hansson, Linus Torvalds
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 <redacted> --- drivers/mmc/core/core.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+)
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 0520064..ced66b8 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c@@ -204,6 +204,23 @@ 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); }
--
2.4.3