scsi: ufs: core: Fix wrong Task Tag used in task management request UPIUs

In __ufshcd_issue_tm_cmd(), it is not correct to use hba->nutrs + req->tag
as the Task Tag in a TMR UPIU. Directly use req->tag as the Task Tag.

Fixes: e293313262d3 ("scsi: ufs: Fix broken task management command implementation")
Link: https://lore.kernel.org/r/1617262750-4864-3-git-send-email-cang@codeaurora.org
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 564918f..d3d05e9 100644 (file)
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -6386,38 +6386,34 @@ static int __ufshcd_issue_tm_cmd(struct ufs_hba *hba,
        DECLARE_COMPLETION_ONSTACK(wait);
        struct request *req;
        unsigned long flags;
-       int free_slot, task_tag, err;
+       int task_tag, err;
 
        /*
-        * Get free slot, sleep if slots are unavailable.
-        * Even though we use wait_event() which sleeps indefinitely,
-        * the maximum wait time is bounded by %TM_CMD_TIMEOUT.
+        * blk_get_request() is used here only to get a free tag.
         */
        req = blk_get_request(q, REQ_OP_DRV_OUT, 0);
        if (IS_ERR(req))
                return PTR_ERR(req);
 
        req->end_io_data = &wait;
-       free_slot = req->tag;
-       WARN_ON_ONCE(free_slot < 0 || free_slot >= hba->nutmrs);
        ufshcd_hold(hba, false);
 
        spin_lock_irqsave(host->host_lock, flags);
-       task_tag = hba->nutrs + free_slot;
        blk_mq_start_request(req);
 
+       task_tag = req->tag;
        treq->req_header.dword_0 |= cpu_to_be32(task_tag);
 
-       memcpy(hba->utmrdl_base_addr + free_slot, treq, sizeof(*treq));
-       ufshcd_vops_setup_task_mgmt(hba, free_slot, tm_function);
+       memcpy(hba->utmrdl_base_addr + task_tag, treq, sizeof(*treq));
+       ufshcd_vops_setup_task_mgmt(hba, task_tag, tm_function);
 
        /* send command to the controller */
-       __set_bit(free_slot, &hba->outstanding_tasks);
+       __set_bit(task_tag, &hba->outstanding_tasks);
 
        /* Make sure descriptors are ready before ringing the task doorbell */
        wmb();
 
-       ufshcd_writel(hba, 1 << free_slot, REG_UTP_TASK_REQ_DOOR_BELL);
+       ufshcd_writel(hba, 1 << task_tag, REG_UTP_TASK_REQ_DOOR_BELL);
        /* Make sure that doorbell is committed immediately */
        wmb();
 
@@ -6437,24 +6433,24 @@ static int __ufshcd_issue_tm_cmd(struct ufs_hba *hba,
                ufshcd_add_tm_upiu_trace(hba, task_tag, UFS_TM_ERR);
                dev_err(hba->dev, "%s: task management cmd 0x%.2x timed-out\n",
                                __func__, tm_function);
-               if (ufshcd_clear_tm_cmd(hba, free_slot))
-                       dev_WARN(hba->dev, "%s: unable clear tm cmd (slot %d) after timeout\n",
-                                       __func__, free_slot);
+               if (ufshcd_clear_tm_cmd(hba, task_tag))
+                       dev_WARN(hba->dev, "%s: unable to clear tm cmd (slot %d) after timeout\n",
+                                       __func__, task_tag);
                err = -ETIMEDOUT;
        } else {
                err = 0;
-               memcpy(treq, hba->utmrdl_base_addr + free_slot, sizeof(*treq));
+               memcpy(treq, hba->utmrdl_base_addr + task_tag, sizeof(*treq));
 
                ufshcd_add_tm_upiu_trace(hba, task_tag, UFS_TM_COMP);
        }
 
        spin_lock_irqsave(hba->host->host_lock, flags);
-       __clear_bit(free_slot, &hba->outstanding_tasks);
+       __clear_bit(task_tag, &hba->outstanding_tasks);
        spin_unlock_irqrestore(hba->host->host_lock, flags);
 
+       ufshcd_release(hba);
        blk_put_request(req);
 
-       ufshcd_release(hba);
        return err;
 }