Re: [RFC PATCH v3.1 00/27] Add support UHS-II for GL9755

Adrian Hunter
2020-12-08T08:49:39Z

On 8/12/20 9:58 am, AKASHI Takahiro wrote:
> Adrian,
>
> On Thu, Dec 03, 2020 at 11:55:23AM +0200, Adrian Hunter wrote:
>> On 1/12/20 5:09 am, AKASHI Takahiro wrote:
>>> Adrian,
>>>
>>> Thank you for your review comments.
>>>
>>> On Thu, Nov 26, 2020 at 10:18:55AM +0200, Adrian Hunter wrote:
>>>> On 25/11/20 9:41 am, AKASHI Takahiro wrote:
>>>>> Gentle ping;
>>>>>
>>>>> On Fri, Nov 06, 2020 at 11:26:59AM +0900, AKASHI Takahiro wrote:
>>>>>> This is an interim snapshot of our next version, v4, for enabling
>>>>>> UHS-II on MMC/SD.
>>>>>>
>>>>>> It is focused on 'sdhci' side to address Adrian's comments regarding
>>>>>> "modularising" sdhci-uhs2.c.
>>>>>> The whole aim of this version is to get early feedback from Adrian (and
>>>>>> others) on this issue. Without any consensus about the code structure,
>>>>>
>>>>> Any comments so far?
>>>>>
>>>>
>>>> Overall, I like this approach of separating UHS2 from legacy sdhci as much
>>>> as possible. The only major change, is to drop support for legacy quirks
>>>> and features that you do not need. The reason for that, is that there may
>>>> be few drivers that end up with UHS-II support (opting instead for SD
>>>> Express), so there is no point going to a lot of trouble to support things
>>>> that never get used.
>>>>
>>>> From what I have seen that looks like it includes:
>>>> - any quirks
>>>
>>> GLI driver (gl9755) needs
>>> * SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC
>>> * SDHCI_QUIRK2_BROKEN_DDR50
>>> but they are managed in sdhci code.
>>>
>>>> - SDHCI LED support
>>>> - external DMA support
>>>
>>> Should we add 'depends on !SDHCI_UHS2' to MMC_SDHCI_EXTERNAL_DMA?
>>>
>>>> In this regard, the important thing is to have a comment somewhere that
>>>> lists what is not supported.
>>>>
>>>> I have only looked at SDHCI patches so far, and only up to about patch 20,
>>>> but maybe that gives you enough to go on for a while.
>>>
>>> Well, I have almost done.
>>> Can I expect your comments on the patches #21-#27 as well soon?
>>
>> I have made some more comments and that is all for now, except for anything
>> more you wish to discuss.
>
> Thank you.
> I assume that you don't have any objection against adding extra hooks
> to sdhci_ops in patch#23 and #25, do you?

No objections at the moment.

>
> If so, since we don't have any critical issues to discuss,
> I hope that my changes will be contained in the new version
> where a major rework will be done on the core side by Ben.

Ok