[PATCH v5 2/2] scsi: ufs: Fix wrong Task Tag used in task management request UPIUs

Can Guo
2021-04-01T07:39:53Z

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

Fixes: e293313262d3 ("scsi: ufs: Fix broken task management command implementation")

Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Can Guo <cang@codeaurora.org>
---
drivers/scsi/ufs/ufshcd.c | 30 +++++++++++++-----------------
1 file changed, 13 insertions(+), 17 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index d4f8cb2..ce5f3fea 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -6446,38 +6446,34 @@ 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();

@@ -6497,24 +6493,24 @@ 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;
}