[RESEND PATCH v3] mmc: dw_mmc: revise the reset path in runtime resume

Ziyuan Xu xzy.xu at rock-chips.com
Wed Jan 4 17:50:18 PST 2017

Immediately after reset, issue the command which sets
update_clock_register_only bit, the card clock will restart. Revise
dw_mci_ctrl_reset to dw_mci_reset, which has wrapped this sequence.

Moreover, we don't need to reset host without active slot.

The patch fixes commit e9ed8835e990 ("mmc: dw_mmc: add runtime PM
callback"). MMC_PM_KEEP_POWEP is disabled for SD card and eMMC slots, so
that they have no chance to invoke dw_mci_setup_bus for update clock
behaviour. Let's consummate it.

Reported-by: Randy Li <randy.li at rock-chips.com>
Signed-off-by: Ziyuan Xu <xzy.xu at rock-chips.com>
Signed-off-by: Shawn Lin <shawn.lin at rock-chips.com>


Changes in v3:
- only reset host with active slot.
- add Shawn's Signed-off tag

Changes in v2:
- update the commit message
- use dw_mci_reset instead of dw_mci_ctrl_reset

 drivers/mmc/host/dw_mmc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index b44306b..bd21242 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -3324,7 +3324,7 @@ int dw_mci_runtime_resume(struct device *dev)
 	if (ret)
 		goto err;
-	if (!dw_mci_ctrl_reset(host, SDMMC_CTRL_ALL_RESET_FLAGS)) {
+	if (host->cur_slot && !dw_mci_reset(host)) {
 		ret = -ENODEV;
 		goto err;

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