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RE: [PATCH v2] mmc: sdhci-of-esdhc: fixup PRESENT_STATE read

Started by"Y.B. Lu" <yangbo.lu@nxp.com>
First post2016-11-14 09:40 +0100
Last post2016-11-14 11:00 +0100
Articles 4 — 3 participants

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  RE: [PATCH v2] mmc: sdhci-of-esdhc: fixup PRESENT_STATE read "Y.B. Lu" <yangbo.lu@nxp.com> - 2016-11-14 09:40 +0100
    RE: [PATCH v2] mmc: sdhci-of-esdhc: fixup PRESENT_STATE read Michael Walle <michael@walle.cc> - 2016-11-14 10:00 +0100
      Re: [PATCH v2] mmc: sdhci-of-esdhc: fixup PRESENT_STATE read Adrian Hunter <adrian.hunter@intel.com> - 2016-11-14 10:50 +0100
        Re: [PATCH v2] mmc: sdhci-of-esdhc: fixup PRESENT_STATE read Michael Walle <michael@walle.cc> - 2016-11-14 11:00 +0100

#1521420 — RE: [PATCH v2] mmc: sdhci-of-esdhc: fixup PRESENT_STATE read

From"Y.B. Lu" <yangbo.lu@nxp.com>
Date2016-11-14 09:40 +0100
SubjectRE: [PATCH v2] mmc: sdhci-of-esdhc: fixup PRESENT_STATE read
Message-ID<sDkY1-4yt-29@gated-at.bofh.it>
> -----Original Message-----
> From: Michael Walle [mailto:michael@walle.cc]
> Sent: Saturday, November 12, 2016 12:04 AM
> To: linux-kernel@vger.kernel.org
> Cc: linux-mmc@vger.kernel.org; Ulf Hansson; Adrian Hunter; yangbo lu;
> Michael Walle
> Subject: [PATCH v2] mmc: sdhci-of-esdhc: fixup PRESENT_STATE read
> 
> 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>
> Fixes: 87a18a6a5652 ("mmc: mmc: Use ->card_busy() to detect busy cards in
> __mmc_switch()")
> ---
> 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 | 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..f9c84bb 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 register. Move the
> corresponding
> +	 * bits around.
> +	 */
> +	if (spec_reg == SDHCI_PRESENT_STATE) {
> +		ret = value & ~0xf8000000;

[Lu Yangbo-B47093] I think the bits which should be cleaned before following '|=' are 0x01f00000 not 0xf8000000, right?
:)

> +		ret |= (value >> 4) & SDHCI_DATA_LVL_MASK;
> +		ret |= (value << 1) & 0x01000000;
> +		return ret;
> +	}
> +
>  	ret = value;
>  	return ret;
>  }
> --
> 2.1.4

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#1521435

FromMichael Walle <michael@walle.cc>
Date2016-11-14 10:00 +0100
Message-ID<sDlho-4FD-21@gated-at.bofh.it>
In reply to#1521420
Am 2016-11-14 04:00, schrieb Y.B. Lu:
>> -----Original Message-----
>> From: Michael Walle [mailto:michael@walle.cc]
>> Sent: Saturday, November 12, 2016 12:04 AM
>> To: linux-kernel@vger.kernel.org
>> Cc: linux-mmc@vger.kernel.org; Ulf Hansson; Adrian Hunter; yangbo lu;
>> Michael Walle
>> Subject: [PATCH v2] mmc: sdhci-of-esdhc: fixup PRESENT_STATE read
>> 
>> 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>
>> Fixes: 87a18a6a5652 ("mmc: mmc: Use ->card_busy() to detect busy cards 
>> in
>> __mmc_switch()")
>> ---
>> 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 | 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..f9c84bb 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 register. Move the
>> corresponding
>> +	 * bits around.
>> +	 */
>> +	if (spec_reg == SDHCI_PRESENT_STATE) {
>> +		ret = value & ~0xf8000000;
> 
> [Lu Yangbo-B47093] I think the bits which should be cleaned before
> following '|=' are 0x01f00000 not 0xf8000000, right?
> :)

Its neither 0x01f00000 nor 0xf8000000 :( I'll put the bits definition 
into the comment the next time, so everyone can review them. bit[31:24] 
are the line DAT[7:0] line signal level. bit[23] is command signal 
level. All other bits are the same as in the standard SDHC PRESENT_STATE 
register.

I want to keep all but the upper 9 bits from the original value, 
therefore, this should be the correct mask:
	ret = value & ~0xff800000;

-michael

> 
>> +		ret |= (value >> 4) & SDHCI_DATA_LVL_MASK;
>> +		ret |= (value << 1) & 0x01000000;
>> +		return ret;
>> +	}
>> +
>>  	ret = value;
>>  	return ret;
>>  }
>> --
>> 2.1.4

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#1521458

FromAdrian Hunter <adrian.hunter@intel.com>
Date2016-11-14 10:50 +0100
Message-ID<sDm3L-5c7-5@gated-at.bofh.it>
In reply to#1521435
On 14/11/16 10:50, Michael Walle wrote:
> Am 2016-11-14 04:00, schrieb Y.B. Lu:
>>> -----Original Message-----
>>> From: Michael Walle [mailto:michael@walle.cc]
>>> Sent: Saturday, November 12, 2016 12:04 AM
>>> To: linux-kernel@vger.kernel.org
>>> Cc: linux-mmc@vger.kernel.org; Ulf Hansson; Adrian Hunter; yangbo lu;
>>> Michael Walle
>>> Subject: [PATCH v2] mmc: sdhci-of-esdhc: fixup PRESENT_STATE read
>>>
>>> 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>
>>> Fixes: 87a18a6a5652 ("mmc: mmc: Use ->card_busy() to detect busy cards in
>>> __mmc_switch()")
>>> ---
>>> 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 | 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..f9c84bb 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 register. Move the
>>> corresponding
>>> +     * bits around.
>>> +     */
>>> +    if (spec_reg == SDHCI_PRESENT_STATE) {
>>> +        ret = value & ~0xf8000000;
>>
>> [Lu Yangbo-B47093] I think the bits which should be cleaned before
>> following '|=' are 0x01f00000 not 0xf8000000, right?
>> :)
> 
> Its neither 0x01f00000 nor 0xf8000000 :( I'll put the bits definition into
> the comment the next time, so everyone can review them. bit[31:24] are the
> line DAT[7:0] line signal level. bit[23] is command signal level. All other
> bits are the same as in the standard SDHC PRESENT_STATE register.
> 
> I want to keep all but the upper 9 bits from the original value, therefore,
> this should be the correct mask:
>     ret = value & ~0xff800000;

Why keep bits 22:20 ?  Isn't it more logical to keep 19:0 (i.e. ret = value
& 0xfffff)

> 
> -michael
> 
>>
>>> +        ret |= (value >> 4) & SDHCI_DATA_LVL_MASK;
>>> +        ret |= (value << 1) & 0x01000000;
>>> +        return ret;
>>> +    }
>>> +
>>>      ret = value;
>>>      return ret;
>>>  }
>>> -- 
>>> 2.1.4
> 
>

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#1521467

FromMichael Walle <michael@walle.cc>
Date2016-11-14 11:00 +0100
Message-ID<sDmdr-5fH-15@gated-at.bofh.it>
In reply to#1521458
Am 2016-11-14 10:37, schrieb Adrian Hunter:
> On 14/11/16 10:50, Michael Walle wrote:
>> Am 2016-11-14 04:00, schrieb Y.B. Lu:
>>>> -----Original Message-----
>>>> From: Michael Walle [mailto:michael@walle.cc]
>>>> Sent: Saturday, November 12, 2016 12:04 AM
>>>> To: linux-kernel@vger.kernel.org
>>>> Cc: linux-mmc@vger.kernel.org; Ulf Hansson; Adrian Hunter; yangbo 
>>>> lu;
>>>> Michael Walle
>>>> Subject: [PATCH v2] mmc: sdhci-of-esdhc: fixup PRESENT_STATE read
>>>> 
>>>> 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>
>>>> Fixes: 87a18a6a5652 ("mmc: mmc: Use ->card_busy() to detect busy 
>>>> cards in
>>>> __mmc_switch()")
>>>> ---
>>>> 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 | 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..f9c84bb 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 register. Move the
>>>> corresponding
>>>> +     * bits around.
>>>> +     */
>>>> +    if (spec_reg == SDHCI_PRESENT_STATE) {
>>>> +        ret = value & ~0xf8000000;
>>> 
>>> [Lu Yangbo-B47093] I think the bits which should be cleaned before
>>> following '|=' are 0x01f00000 not 0xf8000000, right?
>>> :)
>> 
>> Its neither 0x01f00000 nor 0xf8000000 :( I'll put the bits definition 
>> into
>> the comment the next time, so everyone can review them. bit[31:24] are 
>> the
>> line DAT[7:0] line signal level. bit[23] is command signal level. All 
>> other
>> bits are the same as in the standard SDHC PRESENT_STATE register.
>> 
>> I want to keep all but the upper 9 bits from the original value, 
>> therefore,
>> this should be the correct mask:
>>     ret = value & ~0xff800000;
> 
> Why keep bits 22:20 ?  Isn't it more logical to keep 19:0 (i.e. ret = 
> value
> & 0xfffff)

These are 0 according to the datasheet but of course, it makes more 
sense to mask these, too.

-michael

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