On 15/04/16 20:29, Dong Aisheng wrote: > Currently when card type supports EXT_CSD_CARD_TYPE_DDR_1_8V > which means it can work on DDR mode with either 3.3v IO or 1.8v > IO voltage. MMC core will first try 1.8v then 3.3v if host claims > MMC_CAP_1_8V_DDR support. > However the host driver voltage switch code does not check NO_1_8_V > quirk which may set a wrong 1.8v and causes the card fixed to 3.3v > VIO un-work. > > Checking 1.8V quirk before setting it to avoid such issue. We need to look forward to when SDHCI_QUIRK2_NO_1_8_V doesn't exist. There are two possibilities: 1. Add MMC_CAP_3_3V_DDR and support to core and use that instead of MMC_CAP_1_8V_DDR. You'll need Ulf's feedback on that. 2. Replace ->start_signal_voltage_switch() i.e. host->mmc_host_ops.start_signal_voltage_switch = esdhci_start_signal_voltage_switch; You will also need to change all calls to sdhci_start_signal_voltage_switch() with host->mmc->ops->start_signal_voltage_switch(), but that needs to be done anyway. > > CC: stable <stable@xxxxxxxxxxxxxxx> > Signed-off-by: Dong Aisheng <aisheng.dong@xxxxxxx> > --- > drivers/mmc/host/sdhci.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c > index 2338aab..96ccb15 100644 > --- a/drivers/mmc/host/sdhci.c > +++ b/drivers/mmc/host/sdhci.c > @@ -1683,6 +1683,8 @@ static int sdhci_do_signal_voltage_switch(struct sdhci_host *host, > > return -EAGAIN; > case MMC_SIGNAL_VOLTAGE_180: > + if (host->quirks2 & SDHCI_QUIRK2_NO_1_8_V) > + return -EINVAL; > /* > * Enable 1.8V Signal Enable in the Host Control2 > * register > -- 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
