On 02/08/17 02:58, Zhoujie Wu wrote:
> 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 update to 0.
> -> mmc_claim_host
> -> sdhci_runtime_resume_host
> -> sdhci_start_signal_voltage_switch
We ought to be able to skip restoring the I/O state when the power is off i.e.:
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index cf2166e4190d..4a70f2f765b6 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;
> -> 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.
>
> Signed-off-by: Zhoujie Wu <zjwu@xxxxxxxxxxx>
> ---
> Hi Ulf,
> Not sure if this is the best way to fix it. Please help to suggest. Thanks.
>
> drivers/mmc/host/sdhci.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index ecd0d43..011ebbe 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1878,7 +1878,7 @@ int sdhci_start_signal_voltage_switch(struct mmc_host *mmc,
> ctrl &= ~SDHCI_CTRL_VDD_180;
> sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
>
> - if (!IS_ERR(mmc->supply.vqmmc)) {
> + if ((!IS_ERR(mmc->supply.vqmmc)) && mmc->ios.vdd) {
> ret = mmc_regulator_set_vqmmc(mmc, ios);
> if (ret) {
> pr_warn("%s: Switching to 3.3V signalling voltage failed\n",
>
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