[PATCH v2] ufs: core: Fix error handler host_sem issue

[Bart Van Assche]

On 10/7/25 11:55 PM, peter.wang at mediatek.com wrote:
> Fix the issue where host_sem is not released due to a new return
> patch in commit f966e02ae521. Check pm_op_in_progress before
> acquiring hba->host_sem to prevent deadlocks and ensure proper
> resource management during error handling. Add comment for
> use ufshcd_rpm_get_noresume() to safely perform link recovery
> without interfering with ongoing PM operations.
> 
> Fixes: f966e02ae521 ("scsi: ufs: core: Fix runtime suspend error deadlock")
> Reported-by: Dan Carpenter <dan.carpenter at linaro.org>
> Signed-off-by: Peter Wang <peter.wang at mediatek.com>
> ---
>   drivers/ufs/core/ufshcd.c | 22 ++++++++++++++--------
>   1 file changed, 14 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index 8185a7791923..ff7a3d60b11d 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -6670,6 +6670,20 @@ static void ufshcd_err_handler(struct work_struct *work)
>   		 hba->saved_uic_err, hba->force_reset,
>   		 ufshcd_is_link_broken(hba) ? "; link is broken" : "");
>   
> +	/*
> +	 * Use ufshcd_rpm_get_noresume() here to safely perform link recovery
> +	 * even if an error occurs during runtime suspend or runtime resume.
> +	 * This avoids potential deadlocks that could happen if we tried to
> +	 * resume the device while a PM operation is already in progress.
> +	 */
> +	ufshcd_rpm_get_noresume(hba);
> +	if (hba->pm_op_in_progress) {
> +		ufshcd_link_recovery(hba);
> +		ufshcd_rpm_put(hba);
> +		return;
> +	}
> +	ufshcd_rpm_put(hba);
> +
>   	down(&hba->host_sem);
>   	spin_lock_irqsave(hba->host->host_lock, flags);
>   	if (ufshcd_err_handling_should_stop(hba)) {
> @@ -6681,14 +6695,6 @@ static void ufshcd_err_handler(struct work_struct *work)
>   	}
>   	spin_unlock_irqrestore(hba->host->host_lock, flags);
>   
> -	ufshcd_rpm_get_noresume(hba);
> -	if (hba->pm_op_in_progress) {
> -		ufshcd_link_recovery(hba);
> -		ufshcd_rpm_put(hba);
> -		return;
> -	}
> -	ufshcd_rpm_put(hba);
> -
>   	ufshcd_err_handling_prepare(hba);
>   
>   	spin_lock_irqsave(hba->host->host_lock, flags);

Thanks!

Reviewed-by: Bart Van Assche <bvanassche at acm.org>