Re: [PATCH v4] mmc: sdhci-of-esdhc: fixup PRESENT_STATE read

[Ulf Hansson]

+stable

On 15 November 2016 at 11:13, Michael Walle <michael@xxxxxxxx> wrote:
> Since commit 87a18a6a5652 ("mmc: mmc: Use ->card_busy() to detect busy
> cards in __mmc_switch()") the ESDHC driver is broken:
>   mmc0: Card stuck in programming state! __mmc_switch
>   mmc0: error -110 whilst initialising MMC card
>
> Since this commit __mmc_switch() uses ->card_busy(), which is
> sdhci_card_busy() for the esdhc driver. sdhci_card_busy() uses the
> PRESENT_STATE register, specifically the DAT0 signal level bit. But the
> ESDHC uses a non-conformant PRESENT_STATE register, thus a read fixup is
> required to make the driver work again.
>
> Signed-off-by: Michael Walle <michael@xxxxxxxx>
> Fixes: 87a18a6a5652 ("mmc: mmc: Use ->card_busy() to detect busy cards in __mmc_switch()")
> Acked-by: Yangbo Lu <yangbo.lu@xxxxxxx>

Thanks, applied for fixes and added a stable tag.

Kind regards
Uffe

> ---
> v4:
>  - add and use SDHCI_CMD_LVL macro
>  - fix typo in comment, thanks alex
>  - add acked-by
>
> v3:
>  - explain the bits in the comments
>  - use bits[19:0] from the original value, all other will be taken from the
>    fixup value.
>
> v2:
>  - use lower bits of the original value (that was actually a typo)
>  - add fixes tag
>  - fix typo
>
>  drivers/mmc/host/sdhci-of-esdhc.c | 14 ++++++++++++++
>  drivers/mmc/host/sdhci.h          |  1 +
>  2 files changed, 15 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
> index fb71c86..1bb11e4 100644
> --- a/drivers/mmc/host/sdhci-of-esdhc.c
> +++ b/drivers/mmc/host/sdhci-of-esdhc.c
> @@ -66,6 +66,20 @@ static u32 esdhc_readl_fixup(struct sdhci_host *host,
>                         return ret;
>                 }
>         }
> +       /*
> +        * The DAT[3:0] line signal levels and the CMD line signal level are
> +        * not compatible with standard SDHC register. The line signal levels
> +        * DAT[7:0] are at bits 31:24 and the command line signal level is at
> +        * bit 23. All other bits are the same as in the standard SDHC
> +        * register.
> +        */
> +       if (spec_reg == SDHCI_PRESENT_STATE) {
> +               ret = value & 0x000fffff;
> +               ret |= (value >> 4) & SDHCI_DATA_LVL_MASK;
> +               ret |= (value << 1) & SDHCI_CMD_LVL;
> +               return ret;
> +       }
> +
>         ret = value;
>         return ret;
>  }
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index c722cd2..ea38962 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -73,6 +73,7 @@
>  #define  SDHCI_DATA_LVL_MASK   0x00F00000
>  #define   SDHCI_DATA_LVL_SHIFT 20
>  #define   SDHCI_DATA_0_LVL_MASK        0x00100000
> +#define  SDHCI_CMD_LVL         0x01000000
>
>  #define SDHCI_HOST_CONTROL     0x28
>  #define  SDHCI_CTRL_LED                0x01
> --
> 2.1.4
>