On 15/10/20 5:38 am, Jisheng Zhang wrote:
> On Thu, 15 Oct 2020 10:12:07 +0800 Jisheng Zhang wrote:
>
>
>>
>> On Wed, 14 Oct 2020 22:44:50 +0300 Adrian Hunter wrote:
>>
>>>
>>>
>>> + Chunyan
>>>
>>> On 14/10/20 1:32 pm, Jisheng Zhang wrote:
>>>> Auto CMD Auto Select can only be used when v4_mode is enabled.
>>>
>>> The SDHCI spec. doesn't seem to say that. AFAICS it refers only to v4.1 not
>>> v4 mode.
>>
>> 4.10 defines the "Auto CMD Auto Select" mode, v4 mode bit in SDHCI_HOST_CONTROL2
>> selects V3 compatible or V4 compatible mode, I think the v4 here includes
>> v4.0, v4.1 and v4.2, so if we want to use the mode we have to ensure v4_mode
>
> So if we want to use the "Auto CMD Auto Select" mode, we have to ensure v4 mode
> is enabled.
But that is not exactly what the SDHCI spec. says. It is quite explicit
about which registers and bit fields are affected by "Host Version 4 Enable =1".
So the question is whether this is standard or a quirk of your controller.
>
>> is enabled.
>>
>> thanks
>>
>>>
>>>>
>>>> Fixes: 427b6514d095 ("mmc: sdhci: Add Auto CMD Auto Select support")
>>>> Signed-off-by: Jisheng Zhang <Jisheng.Zhang@xxxxxxxxxxxxx>
>>>> ---
>>>> drivers/mmc/host/sdhci.c | 3 ++-
>>>> 1 file changed, 2 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>>>> index 592a55a34b58..5e0ec5df4074 100644
>>>> --- a/drivers/mmc/host/sdhci.c
>>>> +++ b/drivers/mmc/host/sdhci.c
>>>> @@ -1386,7 +1386,8 @@ static inline void sdhci_auto_cmd_select(struct sdhci_host *host,
>>>> * Select' is recommended rather than use of 'Auto CMD12
>>>> * Enable' or 'Auto CMD23 Enable'.
>>>> */
>>>> - if (host->version >= SDHCI_SPEC_410 && (use_cmd12 || use_cmd23)) {
>>>> + if (host->version >= SDHCI_SPEC_410 && host->v4_mode &&
>>>> + (use_cmd12 || use_cmd23)) {
>>>> *mode |= SDHCI_TRNS_AUTO_SEL;
>>>>
>>>> ctrl2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>>>>
>>>
>>
>
