Re: [PATCH v2 3/3] mmc: sdhci-msm: drop redundant of_device_id entries

From: Doug Anderson
Date: Wed Jul 13 2022 - 11:58:13 EST


Hi,

On Tue, Jul 12, 2022 at 8:02 AM Krzysztof Kozlowski
<krzysztof.kozlowski@xxxxxxxxxx> wrote:
>
> This reverts three commits:
> 1. Revert "mmc: sdhci-msm: Add compatible string check for sdx65"
> This reverts commit 953706844f0f2fd4dc6984cc010fe6cf51c041f2.
>
> 2. Revert "mmc: sdhci-msm: Add compatible string check for sm8150"
> This reverts commit 5acd6adb65802cc6f9986be3750179a820580d37.
>
> 3. Revert "mmc: sdhci-msm: Add SoC specific compatibles"
> This reverts commit 466614a9765c6fb67e1464d0a3f1261db903834b.
>
> The oldest commit 466614a9765c ("mmc: sdhci-msm: Add SoC specific
> compatibles") did not specify what benefits such multiple compatibles
> bring, therefore assume there is none. On the other hand such approach
> brings a lot of churn to driver maintenance by expecting commit for
> every new compatible, even though it is already covered by the fallback.
>
> There is really no sense in duplicating of_device_id for each
> variant, which is already covered by generic compatible fallback
> qcom,sdhci-msm-v4 or qcom,sdhci-msm-v5.
>
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>

Personally, I would have taken the extra step and added a comment in
the code to prevent someone from doing this again. Maybe like this:

/*
* In the device tree, all boards are required to have _two_ compatible
* strings listed: a SoC-specific one followed by a more generic one.
* Normally we can just rely on the generic string, but we always
* include both so that if we ever find a bug on a specific SoC that
* we need to workaround (like in sdm845/sc7180) that we can quickly
* work around it without any changes to the dts.
*/

In any case:

Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>