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| author | Can Guo <can.guo@oss.qualcomm.com> | 2026-03-25 08:21:48 -0700 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2026-03-27 17:20:29 -0400 |
| commit | dc5dcac5327832bffc1971b1445553823bdebc08 (patch) | |
| tree | 0c5959a2b9155593548b3da45328fa86830fa038 | |
| parent | 10c40143f369a601cc54dd39777843e000b730a6 (diff) | |
| download | lwn-dc5dcac5327832bffc1971b1445553823bdebc08.tar.gz lwn-dc5dcac5327832bffc1971b1445553823bdebc08.zip | |
scsi: ufs: core: Add helpers to pause and resume command processing
In preparation for supporting TX Equalization refreshing, introduce helper
functions to safely pause and resume command processing.
ufshcd_pause_command_processing() ensures the host is in a quiescent state
by stopping the block layer tagset, acquiring the necessary locks
(scan_mutex and clk_scaling_lock), and waiting for any in-flight commands
to complete within a specified timeout.
ufshcd_resume_command_processing() restores the host to its previous
operational state by reversing these steps in the correct order.
Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Can Guo <can.guo@oss.qualcomm.com>
Reviewed-by: Peter Wang <peter.wang@mediatek.com>
Link: https://patch.msgid.link/20260325152154.1604082-7-can.guo@oss.qualcomm.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
| -rw-r--r-- | drivers/ufs/core/ufshcd-priv.h | 2 | ||||
| -rw-r--r-- | drivers/ufs/core/ufshcd.c | 42 |
2 files changed, 44 insertions, 0 deletions
diff --git a/drivers/ufs/core/ufshcd-priv.h b/drivers/ufs/core/ufshcd-priv.h index 4c008230e8d6..45904e5746b2 100644 --- a/drivers/ufs/core/ufshcd-priv.h +++ b/drivers/ufs/core/ufshcd-priv.h @@ -78,6 +78,8 @@ int ufshcd_mcq_sq_cleanup(struct ufs_hba *hba, int task_tag); int ufshcd_mcq_abort(struct scsi_cmnd *cmd); int ufshcd_try_to_abort_task(struct ufs_hba *hba, int tag); void ufshcd_release_scsi_cmd(struct ufs_hba *hba, struct scsi_cmnd *cmd); +int ufshcd_pause_command_processing(struct ufs_hba *hba, u64 timeout_us); +void ufshcd_resume_command_processing(struct ufs_hba *hba); /** * enum ufs_descr_fmt - UFS string descriptor format diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c index d78723dea951..39e6d12e347a 100644 --- a/drivers/ufs/core/ufshcd.c +++ b/drivers/ufs/core/ufshcd.c @@ -1364,6 +1364,48 @@ out: } /** + * ufshcd_pause_command_processing - Pause command processing + * @hba: per-adapter instance + * @timeout_us: timeout in microseconds to wait for pending commands to finish + * + * This function stops new command submissions and waits for existing commands + * to complete. + * + * Return: 0 on success, %-EBUSY if commands did not finish within @timeout_us. + * On failure, all acquired locks are released and the tagset is unquiesced. + */ +int ufshcd_pause_command_processing(struct ufs_hba *hba, u64 timeout_us) +{ + int ret = 0; + + mutex_lock(&hba->host->scan_mutex); + blk_mq_quiesce_tagset(&hba->host->tag_set); + down_write(&hba->clk_scaling_lock); + + if (ufshcd_wait_for_pending_cmds(hba, timeout_us)) { + ret = -EBUSY; + up_write(&hba->clk_scaling_lock); + blk_mq_unquiesce_tagset(&hba->host->tag_set); + mutex_unlock(&hba->host->scan_mutex); + } + + return ret; +} + +/** + * ufshcd_resume_command_processing - Resume command processing + * @hba: per-adapter instance + * + * This function resumes command submissions. + */ +void ufshcd_resume_command_processing(struct ufs_hba *hba) +{ + up_write(&hba->clk_scaling_lock); + blk_mq_unquiesce_tagset(&hba->host->tag_set); + mutex_unlock(&hba->host->scan_mutex); +} + +/** * ufshcd_scale_gear - scale up/down UFS gear * @hba: per adapter instance * @target_gear: target gear to scale to |