Re: [PATCH v5] scsi: ufs: core: call hibern8 notify when hibern8 cmd failed

[Bean Huo <beanhuo@iokpp.de>]

On Wed, 2026-05-06 at 11:16 +0200, Bart Van Assche wrote:
> On 5/6/26 10:47 AM, Bean Huo wrote:
> > Thanks for the explanation. However, the kernel development practice is to
> > not
> > merge infrastructure without at least one in-tree user. Please resubmit this
> > patch together with your platform driver (or at least the hibern8_notify
> > callback that handles ROLLBACK_CHANGE) so reviewers can verify the design is
> > correct and actually works as intended.
> > 
> > @Bart, any idea?
> 
> Everyone who works on Android smartphones has to deal with the following:
> - The upstream-first policy.
> - Not disclosing any aspect of the phone under development until it has
>    been announced publicly.
> 
> Typically two years elapse between the start of testing kernel code for
> a new phone and public announcement. Another 1 - 4 years elapse after
> a phone has been announced until all kernel code for a smartphone is
> upstream. Insisting on not merging any code upstream until a user for
> the code is upstream makes the job of smartphone kernel developers
> harder than necessary.
> 
> This is why I'm fine with deviating from the rule explained in your
> email for small changes.
> 
> Thanks,
> 
> Bart.


Thanks Bart.


@Fang Hongjie, 

I respect the practical constraints Bart described, but my concern is about
design validation, not disclosure. Could you at least show a minimal
hibern8_notify handler that uses ROLLBACK_CHANGE? 

It doesn't need to be the full platform driver, just enough to demonstrate what
"rollback" means concretely (e.g., undo clock gating, restore PHY state, etc.).
Without that, we're merging an API whose semantics are unverifiable.

Especially, other vendors (SS, Qcom, MTK, etc.) should be able to see the
direction and understand whether they also need to handle ROLLBACK_CHANGE in
their own hibern8_notify callbacks.

Otherwise, please include this patch as part of your platform driver patch
series when you submit it, so reviewers can evaluate the infrastructure and its
consumer together.

Kind Regards,
Bean