From 26fb1ba1baf9fe555ff2918e027cef78ee3f54d0 Mon Sep 17 00:00:00 2001 From: Al Cooper Date: Fri, 16 Mar 2012 15:54:17 -0400 Subject: [PATCH] mmc: Prevent 1.8V switch for SD hosts that don't support UHS modes. commit 4188bba0e9e7ba58d231b528df495666f2742b74 upstream. 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 Acked-by: Arindam Nath Acked-by: Philip Rakity Acked-by: Girish K S Signed-off-by: Chris Ball Signed-off-by: Ben Hutchings --- drivers/mmc/host/sdhci.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 6ce32a7a471e..aaeaff2446aa 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -2712,8 +2712,9 @@ 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 */ -- 2.39.5