6.15-stable review patch. If anyone has any objections, please let me know.
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From: Ziqi Chen quic_ziqichen@quicinc.com
[ Upstream commit e97633492f5a3eca7b3ff03b4ef6f993017f7955 ]
When preparing for UFS clock scaling, the UFS driver will quiesce all sdevs queues in the UFS SCSI host tagset list and then unquiesce them in ufshcd_clock_scaling_unprepare(). If the UFS SCSI host async scan is in progress at this time, some LUs may be added to the tagset list between UFS clkscale prepare and unprepare. This can cause two issues:
1. During clock scaling, there may be I/O requests issued through new added queues that have not been quiesced, leading to task abort issue.
2. These new added queues that have not been quiesced will be unquiesced as well when UFS clkscale is unprepared, resulting in warning prints.
Therefore, use the mutex lock scan_mutex in ufshcd_clock_scaling_prepare() and ufshcd_clock_scaling_unprepare() to protect it.
Co-developed-by: Can Guo quic_cang@quicinc.com Signed-off-by: Can Guo quic_cang@quicinc.com Signed-off-by: Ziqi Chen quic_ziqichen@quicinc.com Link: https://lore.kernel.org/r/20250522081233.2358565-1-quic_ziqichen@quicinc.com Suggested-by: Bart Van Assche bvanassche@acm.org Reviewed-by: Bart Van Assche bvanassche@acm.org Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/ufs/core/ufshcd.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c index 04f769d907a44..ea24080c26e89 100644 --- a/drivers/ufs/core/ufshcd.c +++ b/drivers/ufs/core/ufshcd.c @@ -1379,6 +1379,7 @@ static int ufshcd_clock_scaling_prepare(struct ufs_hba *hba, u64 timeout_us) * make sure that there are no outstanding requests when * clock scaling is in progress */ + mutex_lock(&hba->host->scan_mutex); blk_mq_quiesce_tagset(&hba->host->tag_set); mutex_lock(&hba->wb_mutex); down_write(&hba->clk_scaling_lock); @@ -1389,6 +1390,7 @@ static int ufshcd_clock_scaling_prepare(struct ufs_hba *hba, u64 timeout_us) up_write(&hba->clk_scaling_lock); mutex_unlock(&hba->wb_mutex); blk_mq_unquiesce_tagset(&hba->host->tag_set); + mutex_unlock(&hba->host->scan_mutex); goto out; }
@@ -1410,6 +1412,7 @@ static void ufshcd_clock_scaling_unprepare(struct ufs_hba *hba, int err) mutex_unlock(&hba->wb_mutex);
blk_mq_unquiesce_tagset(&hba->host->tag_set); + mutex_unlock(&hba->host->scan_mutex); ufshcd_release(hba); }