| Message ID | 1352796533-12350-4-git-send-email-m.szyprowski@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Marek, On Tue, Nov 13 2012, Marek Szyprowski wrote: > Fixed regulators cannot change their voltage, so disable all voltage range > checking for them, otherwise the driver fails to operate with fixed > regulators. > > Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Perhaps it's a good idea to mention that the regulator API is changing (being fixed) at the same time, and that's why this patch is necessary. > --- > 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 c7851c0..6f6534e 100644 > --- a/drivers/mmc/host/sdhci.c > +++ b/drivers/mmc/host/sdhci.c > @@ -2923,7 +2923,7 @@ int sdhci_add_host(struct sdhci_host *host) > regulator_enable(host->vmmc); > > #ifdef CONFIG_REGULATOR > - if (host->vmmc) { > + if (host->vmmc && regulator_count_voltages(host->vmmc) > 1) { > ret = regulator_is_supported_voltage(host->vmmc, 3300000, > 3300000); > if ((ret <= 0) || (!(caps[0] & SDHCI_CAN_VDD_330))) What about other occasions where is_supported_voltage() is used, like this one -- is it necessary here too? else if (regulator_is_supported_voltage(host->vqmmc, 1800000, 1800000)) regulator_enable(host->vqmmc); Thanks, - Chris.
On Tue, Nov 13, 2012 at 07:45:07AM -0500, Chris Ball wrote: > On Tue, Nov 13 2012, Marek Szyprowski wrote: > > Fixed regulators cannot change their voltage, so disable all voltage range > > checking for them, otherwise the driver fails to operate with fixed > > regulators. > > Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> > Perhaps it's a good idea to mention that the regulator API is changing > (being fixed) at the same time, and that's why this patch is necessary. This should be totally unrelated to any externally visible change in the regulator API, if anything I would expect fixes in the API to *improve* the ability of clients to work with fixed voltage regulators. What's missing here is some explanation as to what the problem is and how it's being fixed. As I understand it this should really be a workaround for hardware which runs cards at out of spec voltages; we have a fixed voltage regulator which claims to not support any of the voltages that are in spec (due to this being what the hardware does) so if we try to use the voltage management stuff in the MMC API it gets upset. As a workaround if we can't change the voltage we just ignore the voltage aspects of the API.
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index c7851c0..6f6534e 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -2923,7 +2923,7 @@ int sdhci_add_host(struct sdhci_host *host) regulator_enable(host->vmmc); #ifdef CONFIG_REGULATOR - if (host->vmmc) { + if (host->vmmc && regulator_count_voltages(host->vmmc) > 1) { ret = regulator_is_supported_voltage(host->vmmc, 3300000, 3300000); if ((ret <= 0) || (!(caps[0] & SDHCI_CAN_VDD_330)))
Fixed regulators cannot change their voltage, so disable all voltage range checking for them, otherwise the driver fails to operate with fixed regulators. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> --- drivers/mmc/host/sdhci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)