Re: [PATCH v3] mmc: sdhci-of-esdhc: fixup PRESENT_STATE read

From: Alexander Stein
Date: Tue Nov 15 2016 - 02:28:43 EST


On Monday 14 November 2016 16:12:27, Michael Walle 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()") ---
> 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 | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-of-esdhc.c
> b/drivers/mmc/host/sdhci-of-esdhc.c index fb71c86..74cf3b1 100644
> --- a/drivers/mmc/host/sdhci-of-esdhc.c
> +++ b/drivers/mmc/host/sdhci-of-esdhc.c
> @@ -66,6 +66,19 @@ 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 line signal level is at bit 23.
^
I guess there is a "command" missing, no?

Best regards,
Alexander