On 28 March 2017 at 11:00, Ludovic Desroches
<ludovic.desroches@xxxxxxxxxxxxx> wrote:
> The controller has different timings for MMC_TIMING_UHS_DDR50 and
> MMC_TIMING_MMC_DDR52. Configuring the controller with SDHCI_CTRL_UHS_DDR50,
> when MMC_TIMING_MMC_DDR52 timings are requested, is not correct and can
> lead to unexpected behavior.
>
> Signed-off-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxxxxxx>
> Fixes: bb5f8ea4d514 ("mmc: sdhci-of-at91: introduce driver for the Atmel SDMMC")
> Cc: <stable@xxxxxxxxxxxxxxx> # 4.4+
Thanks, applied for fixes!
And thanks for really getting to bottom to fix this issue properly!
Kind regards
Uffe
> ---
>
> Hi,
>
> Here is the proper fix (I hope!) to the issue I have since commit e173f8911f09
> ("mmc: core: Update CMD13 polling policy when switch to HS DDR mode"). This
> commit was probably not the root cause but causes some side effect due to a
> bad timing configuration.
>
> I can't explain how it was working before but for sure I was not configuring
> properly the controller timings.
>
> Regards
>
>
> drivers/mmc/host/sdhci-of-at91.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c
> index 814571f..7611fd6 100644
> --- a/drivers/mmc/host/sdhci-of-at91.c
> +++ b/drivers/mmc/host/sdhci-of-at91.c
> @@ -29,6 +29,8 @@
>
> #include "sdhci-pltfm.h"
>
> +#define SDMMC_MC1R 0x204
> +#define SDMMC_MC1R_DDR BIT(3)
> #define SDMMC_CACR 0x230
> #define SDMMC_CACR_CAPWREN BIT(0)
> #define SDMMC_CACR_KEY (0x46 << 8)
> @@ -101,11 +103,18 @@ static void sdhci_at91_set_power(struct sdhci_host *host, unsigned char mode,
> sdhci_set_power_noreg(host, mode, vdd);
> }
>
> +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);
> + sdhci_set_uhs_signaling(host, timing);
> +}
> +
> static const struct sdhci_ops sdhci_at91_sama5d2_ops = {
> .set_clock = sdhci_at91_set_clock,
> .set_bus_width = sdhci_set_bus_width,
> .reset = sdhci_reset,
> - .set_uhs_signaling = sdhci_set_uhs_signaling,
> + .set_uhs_signaling = sdhci_at91_set_uhs_signaling,
> .set_power = sdhci_at91_set_power,
> };
>
> --
> 2.9.0
>
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