On Fri, May 22, 2020 at 03:42:18PM +0300, Dmitry Osipenko wrote: > 22.05.2020 15:26, Thierry Reding пишет: > > On Wed, May 20, 2020 at 01:08:57PM -0700, Sowjanya Komatineni wrote: > >> When auto calibration timeouts, calibration is disabled and fail-safe > >> drive strength values are programmed based on the signal voltage. > >> > >> Different fail-safe drive strength values based on voltage are > >> applicable only for SoCs supporting 3V3 and 1V8 pad controls. > >> > >> So, this patch avoids reading these properties from the device tree > >> for SoCs not using pad controls and the warning of missing properties > >> will not show up on these SoC platforms. > >> > >> Signed-off-by: Sowjanya Komatineni <skomatineni@xxxxxxxxxx> > >> --- > >> drivers/mmc/host/sdhci-tegra.c | 57 ++++++++++++++++++++++++------------------ > >> 1 file changed, 33 insertions(+), 24 deletions(-) > >> > >> diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c > >> index 3e2c510..141b49b 100644 > >> --- a/drivers/mmc/host/sdhci-tegra.c > >> +++ b/drivers/mmc/host/sdhci-tegra.c > >> @@ -605,6 +605,39 @@ static void tegra_sdhci_parse_pad_autocal_dt(struct sdhci_host *host) > >> autocal->pull_down_1v8 = 0; > >> > >> err = device_property_read_u32(host->mmc->parent, > >> + "nvidia,pad-autocal-pull-up-offset-sdr104", > >> + &autocal->pull_up_sdr104); > >> + if (err) > >> + autocal->pull_up_sdr104 = autocal->pull_up_1v8; > >> + > >> + err = device_property_read_u32(host->mmc->parent, > >> + "nvidia,pad-autocal-pull-down-offset-sdr104", > >> + &autocal->pull_down_sdr104); > >> + if (err) > >> + autocal->pull_down_sdr104 = autocal->pull_down_1v8; > >> + > >> + err = device_property_read_u32(host->mmc->parent, > >> + "nvidia,pad-autocal-pull-up-offset-hs400", > >> + &autocal->pull_up_hs400); > >> + if (err) > >> + autocal->pull_up_hs400 = autocal->pull_up_1v8; > >> + > >> + err = device_property_read_u32(host->mmc->parent, > >> + "nvidia,pad-autocal-pull-down-offset-hs400", > >> + &autocal->pull_down_hs400); > >> + if (err) > >> + autocal->pull_down_hs400 = autocal->pull_down_1v8; > >> + > >> + /* > >> + * Different fail-safe drive strength values based on the signaling > >> + * voltage are applicable for SoCs supporting 3V3 and 1V8 pad controls. > >> + * So, avoid reading below device tree properies for SoCs that don't > >> + * have NVQUIRK_NEEDS_PAD_CONTROL. > >> + */ > >> + if (!(tegra_host->soc_data->nvquirks & NVQUIRK_NEEDS_PAD_CONTROL)) > >> + return; > > > > Hm... so what exactly is the difference between NVQUIRK_HAS_PADCALIB? I > > think Tegra30 will also end up calling tegra_sdhci_set_padctrl(), but it > > will then write the default (0) value for these drive strength. Is that > > okay? > > It won't write 0, but skip the writing if values are 0. Technically T30+ > supports the customized strengths, but I'm not sure whether it was ever > tested and whether it's really needed. I think Sowjanya said before that > the default values are always okay for older SoCs. Alright then, in that case: Acked-by: Thierry Reding <treding@xxxxxxxxxx>
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