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

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

[Michael Walle]

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>
---
 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
+	 * bits around.
+	 */
+	if (spec_reg == SDHCI_PRESENT_STATE) {
+		ret = value & 0xf8000000;
+		ret |= (value >> 4) & SDHCI_DATA_LVL_MASK;
+		ret |= (value << 1) & 0x01000000;
+		return ret;
+	}
+
 	ret = value;
 	return ret;
 }
-- 
2.1.4

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

[Adrian Hunter]

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;
>  }
> 

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

[Michael Walle]

Am 2016-11-11 14:15, schrieb Adrian Hunter:
> 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.

ah, right, will do :)

> 
>> ---
>>  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
ok

> 
>> +	 * 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?

ugh, thanks for spotting that. actually all lower bits should be taken 
from the original value. Therefore the first statement should be
  ret = value & ~0xf8000000;

Will post a v2 soon.

-michael