Re: [PATCH 11/11] mmc: core: Add support for Power Off Notification for SD cards

[Linus Walleij]

On Tue, May 4, 2021 at 6:12 PM Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:

> Rather than only deselecting the SD card via a CMD7, before we cut power to
> it at system suspend, at runtime suspend or at shutdown, let's add support
> for a graceful power off sequence via enabling the SD Power Off
> Notification feature.
>
> Note that, the Power Off Notification feature was added in the SD spec
> v4.x, which is several years ago. However, it's still a bit unclear how
> often the SD card vendors decides to implement support for it. To validate
> these changes a Sandisk Extreme PRO A2 64GB has been used, which seems to
> work nicely.
>
> Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>

Given how these things work in some quarters I would not be
surprised if some SD card vendors tend to start to implement
this when they see that Linux (Android) has started to support
it. So let's encourage them:
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>

Yours,
Linus Walleij