Acked-by: Philip Rakity <prakity@xxxxxxxxxxx> On Apr 3, 2012, at 8:46 PM, Nath, Arindam wrote: > Hi, > > >> -----Original Message----- >> From: Chris Ball [mailto:cjb@xxxxxxxxxx] >> Sent: Tuesday, April 03, 2012 6:12 AM >> To: Alan Cooper >> Cc: linux-mmc@xxxxxxxxxxxxxxx; Girish K S; Ulf Hansson; Nath, Arindam; >> Philip Rakity >> Subject: Re: [PATCH] mmc: Prevent 1.8V switch for SD hosts that don't >> support UHS modes. >> >> Hi Al, >> >> On Mon, Apr 02 2012, Alan Cooper wrote: >>> Still hoping for comments on the patch. >> >> Thanks for the reminder; adding a few potential reviewers to CC:. > > Acked-by: Arindam Nath <arindam.nath@xxxxxxx> > > Regards, > Arindam > >> >> - Chris. >> >>> On Fri, Mar 16, 2012 at 3:54 PM, Al Cooper <acooper@xxxxxxxxx> wrote: >>>> The driver should not try to switch to 1.8V when the SD 3.0 host >>>> controller does not have any UHS capabilities bits set (SDR50, DDR50 >>>> or SDR104). See page 72 of "SD Specifications Part A2 SD Host >>>> Controller Simplified Specification Version 3.00" under >>>> "1.8V Signaling Enable". Instead of setting SDR12 and SDR25 in the >> host >>>> capabilities data structure for all V3.0 host controllers, only set >> them >>>> if SDR104, SDR50 or DDR50 is set in the host capabilities register. >> This >>>> will prevent the switch to 1.8V later. >>>> >>>> Signed-off-by: Al Cooper <acooper@xxxxxxxxx> >>>> --- >>>> drivers/mmc/host/sdhci.c | 5 +++-- >>>> 1 files changed, 3 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c >>>> index 8d66706..cdf900e 100644 >>>> --- a/drivers/mmc/host/sdhci.c >>>> +++ b/drivers/mmc/host/sdhci.c >>>> @@ -2762,8 +2762,9 @@ int sdhci_add_host(struct sdhci_host *host) >>>> mmc_card_is_removable(mmc)) >>>> mmc->caps |= MMC_CAP_NEEDS_POLL; >>>> >>>> - /* UHS-I mode(s) supported by the host controller. */ >>>> - if (host->version >= SDHCI_SPEC_300) >>>> + /* Any UHS-I mode in caps implies SDR12 and SDR25 support. >> */ >>>> + if (caps[1] & (SDHCI_SUPPORT_SDR104 | SDHCI_SUPPORT_SDR50 | >>>> + SDHCI_SUPPORT_DDR50)) >>>> mmc->caps |= MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25; >>>> >>>> /* SDR104 supports also implies SDR50 support */ >>>> -- >>>> 1.7.6 >> >> -- >> Chris Ball <cjb@xxxxxxxxxx> <http://printf.net/> >> One Laptop Per Child > -- 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
