[U-Boot] [PATCH v2 1/3] mmc: sdhci: fix the wrong operation when response type is R1b

[Jaehoon Chung <jh80.chung@samsung.com>]

On 03/30/2012 02:24 PM, Lei Wen wrote:

> Hi Jaehoon,
> 
> On Fri, Mar 30, 2012 at 12:36 PM, Jaehoon Chung <jh80.chung@samsung.com> wrote:
>> Hi Lei.
>>
>> First, thanks for implemented the generic sdhci controller.
> 
> It is my pleasure to share this common code, and I'm glad that it is
> used for other platforms now. :)
> 
>>
>> On 03/30/2012 12:33 PM, Lei Wen wrote:
>>
>>> Hi Jaehoon,
>>>
>>> On Fri, Mar 30, 2012 at 10:39 AM, Jaehoon Chung <jh80.chung@samsung.com> wrote:
>>>> When response type is R1b, mask value is added the SDHCI_INT_DAT_END.
>>>> but in while(), didn't check that flag.
>>>> So sdhci controller didn't work fine.
>>>> CMD6 didn't always complete.
>>>
>>> Could you elaborate it more in details?
>>>         do {
>>>                 stat = sdhci_readl(host, SDHCI_INT_STATUS);
>>>                 if (stat & SDHCI_INT_ERROR)
>>>                         break;
>>>         } while ((stat & mask) != mask);
>>> Here in the while condition, if the status read out don't contain all mask,
>>> then the looping would continue.
>>> Do you mean you just need a retry max time set here?
>>
>> I found that didn't initialize the eMMC card.
>> Because when send CMD6, running infinite loop in there.
>> CMD6's mask is set to SDHCI_INT_RESPONSE and SDHCI_INT_DATA_END.
>> (Because response type is R1B).
>> Then mask value maybe is 0x3...
>> stat = sdhci_readl(host, SDHCI_INT_STATUS);
>> stat is 0x1.(cmd is done response).
>> but in while(), stat & mask is 0x1, and mask is 0x3.
>> ...doing while().
>> If just add the timeout, then always produced the timeout error.
> 
> I see your problems. Your silicon only provide SDHCI_INT_RESPONSE for
> r1b, while the standard
> sdhci spec require both the flag is set when the r1b command is finished.
> So my point is you could add a quirk condition check in the previously
> endless loop checking.
> If the quirk is true, and timeout count is met, then you could jump
> out of original looping.
> And for later checking, this timeout could be regarded as no error,
> since the controller would never
> return the SDHCI_INT_DATA_END in your case.


Anyway it's need that use the timeout value. right?
And in our case, It's means that use the quirks?
I didn't find that the sdhci spec require the flag is set when the r1b command is finished.
where is specified?
I just understand that the transfer complete bit should be set to 1,
when send the command with busy flag or read/write with data.
Is this means?

If you want to use the quirks, i will test with applied your opinion.

Best Regards,
Jaehoon Chung

> 
>>
>> How did you test? Is initialize the eMMC card?
>> (I tested with eMMC4.41 (exynos4).)
> 
> I test on many Marvell platforms, with sd, mmc, emmc, they all works fine.
> 
>>