diff options
| author | Eugen Hristev <eugen.hristev@microchip.com> | 2022-06-30 12:09:26 +0300 |
|---|---|---|
| committer | Ulf Hansson <ulf.hansson@linaro.org> | 2022-07-12 13:42:37 +0300 |
| commit | 5987e6ded29d52e42fc7b06aa575c60a25eee38e (patch) | |
| tree | 87f84eadec10e73206874db63c9227196bace21a /drivers/mmc | |
| parent | e427266460826bea21b70f9b2bb29decfb2c2620 (diff) | |
mmc: sdhci-of-at91: fix set_uhs_signaling rewriting of MC1R
In set_uhs_signaling, the DDR bit is being set by fully writing the MC1R
register.
This can lead to accidental erase of certain bits in this register.
Avoid this by doing a read-modify-write operation.
Fixes: d0918764c17b ("mmc: sdhci-of-at91: fix MMC_DDR_52 timing selection")
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Tested-by: Karl Olsen <karl@micro-technic.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20220630090926.15061-1-eugen.hristev@microchip.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc')
| -rw-r--r-- | drivers/mmc/host/sdhci-of-at91.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c index 10fb4cb2c731..cd0134580a90 100644 --- a/drivers/mmc/host/sdhci-of-at91.c +++ b/drivers/mmc/host/sdhci-of-at91.c @@ -100,8 +100,13 @@ static void sdhci_at91_set_clock(struct sdhci_host *host, unsigned int clock) static void sdhci_at91_set_uhs_signaling(struct sdhci_host *host, unsigned int timing) { - if (timing == MMC_TIMING_MMC_DDR52) - sdhci_writeb(host, SDMMC_MC1R_DDR, SDMMC_MC1R); + u8 mc1r; + + if (timing == MMC_TIMING_MMC_DDR52) { + mc1r = sdhci_readb(host, SDMMC_MC1R); + mc1r |= SDMMC_MC1R_DDR; + sdhci_writeb(host, mc1r, SDMMC_MC1R); + } sdhci_set_uhs_signaling(host, timing); } |