Re: [PATCH V1] mmc: sdhci-msm: Enable MMC_CAP_AGGRESSIVE_PM for qualcomm controllers

[Sarthak Garg <quic_sartgarg@quicinc.com>]

On 5/21/2025 6:25 PM, Dmitry Baryshkov wrote:
> On Wed, May 21, 2025 at 12:46:49PM +0530, Sarthak Garg wrote:
>>
>>
>> On 11/15/2024 6:53 PM, Dmitry Baryshkov wrote:
>>> On Fri, 15 Nov 2024 at 12:23, Sarthak Garg <quic_sartgarg@quicinc.com> wrote:
>>>>
>>>>
>>>>
>>>> On 11/4/2024 4:19 PM, Dmitry Baryshkov wrote:
>>>>> On Mon, Nov 04, 2024 at 11:37:22AM +0530, Sarthak Garg wrote:
>>>>>> Enable MMC_CAP_AGGRESSIVE_PM for qualcomm controllers.
>>>>>> This enables runtime PM for eMMC/SD card.
>>>>>
>>>>> Could you please mention, which platforms were tested with this patch?
>>>>> Note, upstream kernel supports a lot of platforms, including MSM8974, I
>>>>> think the oldest one, which uses SDHCI.
>>>>>
>>>>
>>>> This was tested with qdu1000 platform.
>>>
>>> Are you sure that it won't break other platforms?
>>>
>>
>> Thanks for your valuable comment.
>> I am not sure about the older platforms so to avoid issues on older
>> platforms we can enable this for all SDCC version 5.0 targets ?
> 
> No, there are still a lot of platforms. Either explain why this is
> required for all v5 platforms (and won't break those) or find some other
> way, e.g. limit the change to QDU1000, explaining why it is _not_
> applicable to other platforms.
> 

Thanks for your comment.
I agree with your concern but for me also its not possible to test on 
all the platforms.
Lets say if I want to enable this caps for QDU1000 for which it has been 
tested and on any other upcoming target after testing, then how can I 
proceed to enable?

One option I had thought of was to implement this using compatible 
string, then for all the upcoming platforms using this compatible string 
as a fallback.
But this doesn't look optimal to use compatible string for just one flag 
and also this capability is not platform specific and we will be needing 
for all the platforms. Please share your opinion on this.

Another option that I could have thought of is using device tree based 
approach but seems that was not accepted earlier :
https://patchwork.kernel.org/project/linux-mmc/patch/20230129023630.830764-1-chenhuiz@axis.com/

So it would be helpful if you can suggest some approach?