Commit 2824ec9f authored by Sayali Lokhande's avatar Sayali Lokhande Committed by Martin K. Petersen
Browse files

scsi: ufs: Flush exception event before suspend 

Exception event can be raised by the device when system suspend is in
progress. This will result in unclocked register access in exception event
handler as clocks will be turned off during suspend. This change makes sure
to flush exception event handler work in suspend before disabling clocks to
avoid unclocked register access issue.

Link: https://lore.kernel.org/r/1581392451-28743-2-git-send-email-cang@codeaurora.org


Reviewed-by: default avatarBean Huo <beanhuo@micron.com>
Signed-off-by: default avatarSayali Lokhande <sayalil@codeaurora.org>
Signed-off-by: default avatarAsutosh Das <asutoshd@codeaurora.org>
Signed-off-by: default avatarCan Guo <cang@codeaurora.org>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 518b32f1

drivers/scsi/ufs/ufshcd.c

+18 −3
Original line number Diff line number Diff line
@@ -4730,8 +4730,15 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp) 
			 * UFS device needs urgent BKOPs.

			 */

			if (!hba->pm_op_in_progress &&

			    ufshcd_is_exception_event(lrbp->ucd_rsp_ptr))

				schedule_work(&hba->eeh_work);

			    ufshcd_is_exception_event(lrbp->ucd_rsp_ptr) &&

			    schedule_work(&hba->eeh_work)) {

				/*

				 * Prevent suspend once eeh_work is scheduled

				 * to avoid deadlock between ufshcd_suspend

				 * and exception event handler.

				 */

				pm_runtime_get_noresume(hba->dev);

			}

			break;

		case UPIU_TRANSACTION_REJECT_UPIU:

			/* TODO: handle Reject UPIU Response */
@@ -5184,7 +5191,14 @@ static void ufshcd_exception_event_handler(struct work_struct *work) 


out:

	ufshcd_scsi_unblock_requests(hba);

	pm_runtime_put_sync(hba->dev);

	/*

	 * pm_runtime_get_noresume is called while scheduling

	 * eeh_work to avoid suspend racing with exception work.

	 * Hence decrement usage counter using pm_runtime_put_noidle

	 * to allow suspend on completion of exception event handler.

	 */

	pm_runtime_put_noidle(hba->dev);

	pm_runtime_put(hba->dev);

	return;

}
@@ -7925,6 +7939,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) 
			goto enable_gating;

	}



	flush_work(&hba->eeh_work);

	ret = ufshcd_link_state_transition(hba, req_link_state, 1);

	if (ret)

		goto set_dev_active;

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