[PATCH v1] ufs: core: bypass get rpm when err handling with pm_op_in_progress

[Bart Van Assche]

On 9/15/22 04:58, peter.wang at mediatek.com wrote:
> -static void ufshcd_err_handling_prepare(struct ufs_hba *hba)
> +static void ufshcd_err_handling_prepare(struct ufs_hba *hba, bool *rpm_put)
>   {
> -	ufshcd_rpm_get_sync(hba);
> +	if (!hba->pm_op_in_progress) {
> +		ufshcd_rpm_get_sync(hba);
> +		*rpm_put = true;
> +	}
> +

Hi Peter,

I don't think that this patch is sufficient. If 
ufshcd_err_handling_prepare() is called by the host reset handler 
(ufshcd_eh_host_reset_handler()) then the host state will be 
SHOST_RECOVERY. In that state SCSI command submission will hang and 
hence any ufshcd_rpm_get_sync() call will hang.

How about removing the ufshcd_rpm_get_sync() call from 
ufshcd_err_handling_prepare() and the ufshcd_rpm_put() call from 
ufshcd_err_handling_unprepare()? It is guaranteed that no commands are 
in progress for a runtime suspended LUN so the code for aborting pending 
requests in the UFS error handler will be skipped anyway if it is 
invoked for a runtime suspended device.

Thanks,

Bart.