| Message ID | 1628334401-6577-5-git-send-email-stefan.wahren@i2se.com |
|---|---|
| State | New |
| Headers | show |
| Series | ARM: dts: Add Raspberry Pi CM4 & CM4 IO Board support | expand |
On Sat, 7 Aug 2021 at 13:07, Stefan Wahren <stefan.wahren@i2se.com> wrote: > > From: Nicolas Saenz Julienne <nsaenz@kernel.org> > > There is a known bug on BCM2711's SDHCI core integration where the > controller will hang when the difference between the core clock and the > bus clock is too great. Specifically this can be reproduced under the > following conditions: > > - No SD card plugged in, polling thread is running, probing cards at > 100 kHz. > - BCM2711's core clock configured at 500MHz or more. > > So set 200 kHz as the minimum clock frequency available for that board. > > For more information on the issue see this: > https://lore.kernel.org/linux-mmc/20210322185816.27582-1-nsaenz@kernel.org/T/#m11f2783a09b581da6b8a15f302625b43a6ecdeca > > Fixes: f84e411c85be ("mmc: sdhci-iproc: Add support for emmc2 of the BCM2711") > Signed-off-by: Nicolas Saenz Julienne <nsaenz@kernel.org> > Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Applied for fixes and by adding a stable tag, thanks! Kind regards Uffe > --- > drivers/mmc/host/sdhci-iproc.c | 18 ++++++++++++++++++ > 1 file changed, 18 insertions(+) > > diff --git a/drivers/mmc/host/sdhci-iproc.c b/drivers/mmc/host/sdhci-iproc.c > index cce390f..032bf85 100644 > --- a/drivers/mmc/host/sdhci-iproc.c > +++ b/drivers/mmc/host/sdhci-iproc.c > @@ -173,6 +173,23 @@ static unsigned int sdhci_iproc_get_max_clock(struct sdhci_host *host) > return pltfm_host->clock; > } > > +/* > + * There is a known bug on BCM2711's SDHCI core integration where the > + * controller will hang when the difference between the core clock and the bus > + * clock is too great. Specifically this can be reproduced under the following > + * conditions: > + * > + * - No SD card plugged in, polling thread is running, probing cards at > + * 100 kHz. > + * - BCM2711's core clock configured at 500MHz or more > + * > + * So we set 200kHz as the minimum clock frequency available for that SoC. > + */ > +static unsigned int sdhci_iproc_bcm2711_get_min_clock(struct sdhci_host *host) > +{ > + return 200000; > +} > + > static const struct sdhci_ops sdhci_iproc_ops = { > .set_clock = sdhci_set_clock, > .get_max_clock = sdhci_iproc_get_max_clock, > @@ -271,6 +288,7 @@ static const struct sdhci_ops sdhci_iproc_bcm2711_ops = { > .set_clock = sdhci_set_clock, > .set_power = sdhci_set_power_and_bus_voltage, > .get_max_clock = sdhci_iproc_get_max_clock, > + .get_min_clock = sdhci_iproc_bcm2711_get_min_clock, > .set_bus_width = sdhci_set_bus_width, > .reset = sdhci_reset, > .set_uhs_signaling = sdhci_set_uhs_signaling, > -- > 2.7.4 >
diff --git a/drivers/mmc/host/sdhci-iproc.c b/drivers/mmc/host/sdhci-iproc.c index cce390f..032bf85 100644 --- a/drivers/mmc/host/sdhci-iproc.c +++ b/drivers/mmc/host/sdhci-iproc.c @@ -173,6 +173,23 @@ static unsigned int sdhci_iproc_get_max_clock(struct sdhci_host *host) return pltfm_host->clock; } +/* + * There is a known bug on BCM2711's SDHCI core integration where the + * controller will hang when the difference between the core clock and the bus + * clock is too great. Specifically this can be reproduced under the following + * conditions: + * + * - No SD card plugged in, polling thread is running, probing cards at + * 100 kHz. + * - BCM2711's core clock configured at 500MHz or more + * + * So we set 200kHz as the minimum clock frequency available for that SoC. + */ +static unsigned int sdhci_iproc_bcm2711_get_min_clock(struct sdhci_host *host) +{ + return 200000; +} + static const struct sdhci_ops sdhci_iproc_ops = { .set_clock = sdhci_set_clock, .get_max_clock = sdhci_iproc_get_max_clock, @@ -271,6 +288,7 @@ static const struct sdhci_ops sdhci_iproc_bcm2711_ops = { .set_clock = sdhci_set_clock, .set_power = sdhci_set_power_and_bus_voltage, .get_max_clock = sdhci_iproc_get_max_clock, + .get_min_clock = sdhci_iproc_bcm2711_get_min_clock, .set_bus_width = sdhci_set_bus_width, .reset = sdhci_reset, .set_uhs_signaling = sdhci_set_uhs_signaling,