Adrian, On Fri, Aug 21, 2020 at 05:09:01PM +0300, Adrian Hunter wrote: > On 10/07/20 2:11 pm, Ben Chuang wrote: > > From: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx> > > > > sdhci_start_signal_voltage_switch() should be called only in UHS-I mode, > > and not for UHS-II mode. > > > > Signed-off-by: Ben Chuang <ben.chuang@xxxxxxxxxxxxxxxxxxx> > > Signed-off-by: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx> > > --- > > drivers/mmc/host/sdhci.c | 7 ++++++- > > 1 file changed, 6 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c > > index 5511649946b9..7f2537648a08 100644 > > --- a/drivers/mmc/host/sdhci.c > > +++ b/drivers/mmc/host/sdhci.c > > @@ -2623,8 +2623,13 @@ int sdhci_start_signal_voltage_switch(struct mmc_host *mmc, > > /* > > * Signal Voltage Switching is only applicable for Host Controllers > > * v3.00 and above. > > + * But for UHS2, the signal voltage is supplied by vdd2 which is > > + * already 1.8v so no voltage switch required. > > */ > > - if (host->version < SDHCI_SPEC_300) > > + if (host->version < SDHCI_SPEC_300 || > > + (IS_ENABLED(CONFIG_MMC_SDHCI_UHS2) && > > + host->version >= SDHCI_SPEC_400 && > > + host->mmc->flags & MMC_UHS2_SUPPORT)) > > Please look at hooking ->start_signal_voltage_switch() instead Do you mean that you want every platform driver who wants to support UHS-II to set NULL to start_signal_voltage_switch hook even if this hack is platform agnostic? (Another option is that it would be put in sdhci_uhs2_add_host() which is responsible to set MMC_UHS2_SUPPORT.) -Takahiro Akashi > > > > return 0; > > > > ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2); > > >
