From: Adrian Hunter <adrian.hunter@intel.com>
To: Michael Walle <michael@walle.cc>, linux-kernel@vger.kernel.org
Cc: linux-mmc@vger.kernel.org, Ulf Hansson <ulf.hansson@linaro.org>,
yangbo lu <yangbo.lu@freescale.com>
Subject: Re: [PATCH] mmc: sdhci-of-esdhc: fixup PRESENT_STATE read
Date: Fri, 11 Nov 2016 15:15:55 +0200 [thread overview]
Message-ID: <0a5454e6-efa6-744e-4a2d-123a47e7cc40@intel.com> (raw)
In-Reply-To: <1478796456-30549-1-git-send-email-michael@walle.cc>
On 10/11/16 18:47, 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@walle.cc>
Could add a Fixes tag here.
> ---
> drivers/mmc/host/sdhci-of-esdhc.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
> index fb71c86..243fee9 100644
> --- a/drivers/mmc/host/sdhci-of-esdhc.c
> +++ b/drivers/mmc/host/sdhci-of-esdhc.c
> @@ -66,6 +66,18 @@ static u32 esdhc_readl_fixup(struct sdhci_host *host,
> return ret;
> }
> }
> + /*
> + * The DAT[3:0] line signal levels and the CMD line signal level is
> + * not compatible with standard SDHC reegister. Move the corresponding
reegister -> register
> + * bits around.
> + */
> + if (spec_reg == SDHCI_PRESENT_STATE) {
> + ret = value & 0xf8000000;
> + ret |= (value >> 4) & SDHCI_DATA_LVL_MASK;
> + ret |= (value << 1) & 0x01000000;
> + return ret;
SDHCI also uses other bits in SDHCI_PRESENT_STATE like SDHCI_CMD_INHIBIT and
SDHCI_DATA_INHIBIT etc, but this looks like all those bits will be zero. Is
that right?
> + }
> +
> ret = value;
> return ret;
> }
>
next prev parent reply other threads:[~2016-11-11 13:20 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-10 16:47 [PATCH] mmc: sdhci-of-esdhc: fixup PRESENT_STATE read Michael Walle
2016-11-11 13:15 ` Adrian Hunter [this message]
2016-11-11 13:25 ` Michael Walle
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