[U-Boot] mmc: sdhci: Add a quirk to add delay during completion of sdhci_send_cmd

Jaehoon Chung jh80.chung at samsung.com
Mon Apr 8 06:07:56 CEST 2013


Hi,

On 04/08/2013 12:52 PM, Tushar Behera wrote:
> On 04/07/2013 10:27 AM, Jagan Teki wrote:
>> Hi,
>>
>> I saw that you have been added the SDHCI_QUIRK_WAIT_SEND_CMD on below commit
>> http://git.denx.de/?p=u-boot.git;a=commitdiff;h=13243f2eafc4292917178051fe1bb5aab2774dca
>>
>> I need few quires regarding the QUIRK delay.
>> 1. Why the delay is 1000
>> +       if (host->quirks & SDHCI_QUIRK_WAIT_SEND_CMD)
>> +               udelay(1000);
>> +
>> 2. is this delay specific to s5p_sdhci  controller?
> 
> This was specific to s5p_sdhci driver so as to replicate the behavior of
> s5p_mmc driver.
It didn't be denoted to use the udelay(1000) in spec.
But To ensure the completing previous request, it has added the udelay(1000).
> 
>> 3. I have an issue "Controller never released inhibit bit(s)"
>>    but when I enable this quirk on my driver with udelay(10000), it's
>> working.
udelay(10000)? It's too long delay time for completing the request.
Which SoC do you use?

If we can use the get_timer() for busy-waiting, i think that we can remove the udelay().

Best Regards,
Jaehoon Chung
> 
> I am not sure about the exact delay as per the spec. I have added
> Jaehoon to CC who might have additional information about this.
> 
>>
>> Could you please help me.
>>
>> Thanks,
>> Jagan.
>>
> 
> 



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