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authorAl Cooper <alcooperx@gmail.com>2019-09-03 14:51:14 +0300
committerUlf Hansson <ulf.hansson@linaro.org>2019-09-11 16:58:39 +0300
commitc894e33ddc1910e14d6f2a2016f60ab613fd8b37 (patch)
tree470f5dca91458ab89a903f9379770987e34aeb22 /drivers/mmc
parent72976643aef55a2a3eec85e5342a3c3608f66e64 (diff)
downloadlinux-c894e33ddc1910e14d6f2a2016f60ab613fd8b37.tar.xz
mmc: sdhci: Fix incorrect switch to HS mode
When switching from any MMC speed mode that requires 1.8v (HS200, HS400 and HS400ES) to High Speed (HS) mode, the system ends up configured for SDR12 with a 50MHz clock which is an illegal mode. This happens because the SDHCI_CTRL_VDD_180 bit in the SDHCI_HOST_CONTROL2 register is left set and when this bit is set, the speed mode is controlled by the SDHCI_CTRL_UHS field in the SDHCI_HOST_CONTROL2 register. The SDHCI_CTRL_UHS field will end up being set to 0 (SDR12) by sdhci_set_uhs_signaling() because there is no UHS mode being set. The fix is to change sdhci_set_uhs_signaling() to set the SDHCI_CTRL_UHS field to SDR25 (which is the same as HS) for any switch to HS mode. This was found on a new eMMC controller that does strict checking of the speed mode and the corresponding clock rate. It caused the switch to HS400 mode to fail because part of the sequence to switch to HS400 requires a switch from HS200 to HS before going to HS400. Suggested-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Al Cooper <alcooperx@gmail.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc')
-rw-r--r--drivers/mmc/host/sdhci.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index c1ebc26846db..d814dc004bad 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1871,7 +1871,9 @@ void sdhci_set_uhs_signaling(struct sdhci_host *host, unsigned timing)
ctrl_2 |= SDHCI_CTRL_UHS_SDR104;
else if (timing == MMC_TIMING_UHS_SDR12)
ctrl_2 |= SDHCI_CTRL_UHS_SDR12;
- else if (timing == MMC_TIMING_UHS_SDR25)
+ else if (timing == MMC_TIMING_SD_HS ||
+ timing == MMC_TIMING_MMC_HS ||
+ timing == MMC_TIMING_UHS_SDR25)
ctrl_2 |= SDHCI_CTRL_UHS_SDR25;
else if (timing == MMC_TIMING_UHS_SDR50)
ctrl_2 |= SDHCI_CTRL_UHS_SDR50;