From: Bart Van Assche <bvanassche@xxxxxxx> [ Upstream commit 5675c381ea51360b4968b78f23aefda73e3de90d ] Instead of locking and unlocking the clock scaling lock, surround the command queueing code with an RCU reader lock and call synchronize_rcu(). This patch prepares for removal of the clock scaling lock. Link: https://lore.kernel.org/r/20211203231950.193369-16-bvanassche@xxxxxxx Tested-by: Bean Huo <beanhuo@xxxxxxxxxx> Reviewed-by: Adrian Hunter <adrian.hunter@xxxxxxxxx> Reviewed-by: Bean Huo <beanhuo@xxxxxxxxxx> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Stable-dep-of: 1a5665fc8d7a ("scsi: ufs: core: WLUN suspend SSU/enter hibern8 fail recovery") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/scsi/ufs/ufshcd.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index a428b8145dcc..6dd341674110 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -2700,6 +2700,12 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd) if (!down_read_trylock(&hba->clk_scaling_lock)) return SCSI_MLQUEUE_HOST_BUSY; + /* + * Allows the UFS error handler to wait for prior ufshcd_queuecommand() + * calls. + */ + rcu_read_lock(); + switch (hba->ufshcd_state) { case UFSHCD_STATE_OPERATIONAL: case UFSHCD_STATE_EH_SCHEDULED_NON_FATAL: @@ -2766,7 +2772,10 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd) } ufshcd_send_command(hba, tag); + out: + rcu_read_unlock(); + up_read(&hba->clk_scaling_lock); if (ufs_trigger_eh()) { @@ -5952,8 +5961,7 @@ static void ufshcd_err_handling_prepare(struct ufs_hba *hba) } ufshcd_scsi_block_requests(hba); /* Drain ufshcd_queuecommand() */ - down_write(&hba->clk_scaling_lock); - up_write(&hba->clk_scaling_lock); + synchronize_rcu(); cancel_work_sync(&hba->eeh_work); } -- 2.35.1
