Re: [PATCH] scsi: ufs: core: Keep clock-gating hold on failed W-LUN runtime resume

[Martin K. Petersen]

Stanley,

> 1. __ufshcd_wl_suspend() takes one ufshcd_hold() reference and sets
>    hba->clk_gating.is_suspended while the UFS device W-LUN enters
>    RPM_SUSPENDED.
> 2. Since commit eef1d74bf88f ("PM: runtime: Only set runtime_error on
>    suspend callback failures"), a failed runtime resume (for example
>    START STOP UNIT completing with an error) leaves the W-LUN in
>    RPM_SUSPENDED with power.runtime_error == 0, while
>    __ufshcd_wl_resume() already clears hba->clk_gating.is_suspended and
>    calls ufshcd_release().
> 3. The next W-LUN runtime resume runs __ufshcd_wl_resume() again without
>    an intervening suspend and calls ufshcd_release() a second time,
>    dropping a reference it does not own and underflowing
>    hba->clk_gating.active_reqs on UFSHCD_CAP_CLK_GATING hosts.

Applied to 7.4/scsi-fixes, thanks!

-- 
Martin K. Petersen