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

[Sarthak Garg <quic_sartgarg@quicinc.com>]

On 7/24/2025 5:31 PM, Dmitry Baryshkov wrote:
> On Thu, Jul 24, 2025 at 04:45:38PM +0530, Sarthak Garg wrote:
>>
>>
>> On 5/21/2025 9:11 PM, Dmitry Baryshkov wrote:
>>> On 21/05/2025 18:36, Sarthak Garg wrote:
>>>>
>>>>
>>>> On 5/21/2025 8:19 PM, Dmitry Baryshkov wrote:
>>>>> On 21/05/2025 17:35, Sarthak Garg wrote:
>>>>>>
>>>>>>
>>>>>> 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.
>>>>>
>>>>> No need to.
>>>>>   >> I agree with your concern but for me also its not possible
>>>>> to test on
>>>>>> all the platforms.
>>>>>
>>>>> Sure.
>>>>>>> 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?
>>>>>
>>>>> Let's start from the beginning: why do you want to enable it on QDU1000?
>>>>>
>>>>
>>>> QDU1000 is one latest available target where we have enabled this
>>>> and tested. This has been enabled to save power.
>>>
>>> Isn't it a powered device? How much power is the save? Is it worth it?
>>>
>>
>> Sorry I just did basic sanity on QDU1000 device to confirm its not breaking
>> any eMMC functionality and we have also tested SD card on SM8550 as well.
>> For power no's we have stared internal discussions and based on target
>> available for power profiling with eMMC device we will come back.
> 
> So, again, _why_ do we want to enable it? If you haven't measured the
> actual power savings, then it's obviously not a primary reason.
> 
> As for the v5 targets only, they start from SDM845. Have you tested it?
> Does it bring any actual benefits?
> 

Sure will capture the power savings on our target with runtime PM and 
will come back.
In our downstream code its enabled for all our targets and tested for 
quite some time.


~Regards
Sarthak