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

From: Ziyuan Xu
Date: Wed Jan 04 2017 - 20:58:30 EST


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@xxxxxxxxxxxxxx>
Signed-off-by: Ziyuan Xu <xzy.xu@xxxxxxxxxxxxxx>

---

Changes in v3:
- only reset host with active slot.

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)) {
clk_disable_unprepare(host->ciu_clk);
ret = -ENODEV;
goto err;
--
2.7.4