Re: Patch "arm64: dts: qcom: Add support for Xiaomi Redmi Note 9S" has been added to the 6.8-stable tree

Krzysztof Kozlowski
2024-04-10T18:24:53Z

On 10/04/2024 20:02, Greg KH wrote:
> On Wed, Apr 10, 2024 at 07:58:40PM +0200, Konrad Dybcio wrote:
>>
>>
>> On 4/10/24 17:57, Sasha Levin wrote:
>>> This is a note to let you know that I've just added the patch titled
>>>
>>> arm64: dts: qcom: Add support for Xiaomi Redmi Note 9S
>>
>> autosel has been reeaaaaaly going over the top lately, particularly
>> with dts patches.. I'm not sure adding support for a device is
>> something that should go to stable
>
> Simple device ids and quirks have always been stable material.
>

That's true, but maybe DTS should have an exception. I guess you think
this is trivial device ID, because the patch contents is small. But it
is or it can be misleading. The patch adds new small DTS file which
includes another file:

#include "sm7125-xiaomi-common.dtsi"

Which includes another 7 files:

#include <dt-bindings/arm/qcom,ids.h>
#include <dt-bindings/firmware/qcom,scm.h>
#include <dt-bindings/gpio/gpio.h>
#include <dt-bindings/regulator/qcom,rpmh-regulator.h>
#include "sm7125.dtsi"
#include "pm6150.dtsi"
#include "pm6150l.dtsi"

Out of which last three are likely to be changing as well.

This means that following workflow is reasonable and likely:
1. Add sm7125.dtsi (or pm6150.dtsi or pm6150l.dtsi)
2. Add some sm7125 board (out of scope here).
3. Release new kernel, e.g. v6.7.
4. Make more changes to sm7125.dtsi
5. The patch discussed here, so one adding sm7125-xiaomi-curtana.dts.

Now if you backport only (5) above, without (4), it won't work. Might
compile, might not. Even if it compiles, might not work.

The step (4) here might be small, but might be big as well.

IOW, new DTS board is not a quirk, but new hardware description which
relies on other DTS files. Only if all other parts are the same, such
backport is reasonable.

Best regards,
Krzysztof