One issue was found on a removable high speed sd card with
runtime pm enabled.
When SD card is unplugged, it keep printing "Switching to 3.3V
signalling voltage failed".
And found below sequence triggers the error.
mmc_rescan
-> mmc_sd_detect
-> mmc_power_off -- mmc->ios.vdd is updated to 0.
-> mmc_claim_host
-> sdhci_runtime_resume_host
-> sdhci_start_signal_voltage_switch
-> mmc_regulator_set_vqmmc
-> mmc_ocrbitnum_to_vdd
When mmc_ocrbitnum_to_vdd is called, the mmc->ios.vdd is 0, so it
always return -EINVAL. The signal switch will always fail and
print out warning.
Ignore restoring the I/O state when runtime resume if MMC_POWER_OFF.
Signed-off-by: Zhoujie Wu <zjwu@xxxxxxxxxxx>
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
This patch is the updated version for my previous patch
mmc: sdhci: ignore 3.3v voltage switch if ios.vdd is 0.
Suggested by Adrian, so added his name in signed-off-by as well.
drivers/mmc/host/sdhci.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 98700f9..c3f67f1 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2934,7 +2934,8 @@ int sdhci_runtime_resume_host(struct sdhci_host *host)
sdhci_init(host, 0);
- if (mmc->ios.power_mode != MMC_POWER_UNDEFINED) {
+ if (mmc->ios.power_mode != MMC_POWER_UNDEFINED &&
+ mmc->ios.power_mode != MMC_POWER_OFF) {
/* Force clock and power re-program */
host->pwr = 0;
host->clock = 0;
--
1.9.1
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
