RE: [PATCH] scsi: ufs: Allow async suspend/resume callbacks

[Avri Altman]

> Allow UFS suspend/resume callbacks to run in parallel with other
> suspend/resume callbacks. This can recoup dozens of milliseconds on the
> resume path if UFS hardware needs to be powered back on.
> 
> Suspending and resuming asynchronously is safe to do so long as the driver
> callbacks only depend on resources made available by either a) parent
> devices or b) devices explicitly marked as suppliers with device_link_add.
> 
> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Cc: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> Cc: Bart Van Assche <bvanassche@xxxxxxx>
> Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> Cc: Stanley Chu <stanley.chu@xxxxxxxxxxxx>
> Cc: Can Guo <cang@xxxxxxxxxxxxxx>
> Cc: Asutosh Das <asutoshd@xxxxxxxxxxxxxx>
> Cc: Avri Altman <avri.altman@xxxxxxx>
> Cc: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
> Signed-off-by: Vincent Palomares <paillon@xxxxxxxxxx>
> ---
> 
> Are there any suspend/resume dependencies for UFS drivers not tracked by
> the device parent relationship?
> 
> drivers/scsi/ufs/ufshcd.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index b87ff68aa9aa..9ec5c308a0ea 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -9625,6 +9625,7 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem
> *mmio_base, unsigned int irq)
>         async_schedule(ufshcd_async_scan, hba);
>         ufs_sysfs_add_nodes(hba->dev);
> 
> +       device_enable_async_suspend(dev);
>         return 0;
Isn't device_enable_async_suspend is being called for each lun in scsi_sysfs_add_sdev Anyway?

Thanks,
Avri
> 
>  free_tmf_queue:
> --
> 2.32.0.432.gabb21c7263-goog