[PATCH v1 1/1] scsi: ufs: mcq: Fix the search/wrap around logic

From: Bao D. Nguyen
Date: Tue Aug 15 2023 - 21:40:08 EST


The search and wrap around logic in the ufshcd_mcq_sqe_search()
function does not work correctly when the hwq's queue depth
is not a power of two number. Correct it so that any queue depth
with a positive integer value within the supported range would work.

Signed-off-by: Bao D. Nguyen <quic_nguyenb@xxxxxxxxxxx>
---
drivers/ufs/core/ufs-mcq.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/ufs/core/ufs-mcq.c b/drivers/ufs/core/ufs-mcq.c
index 66a4e24..2ba8ec2 100644
--- a/drivers/ufs/core/ufs-mcq.c
+++ b/drivers/ufs/core/ufs-mcq.c
@@ -578,7 +578,6 @@ static bool ufshcd_mcq_sqe_search(struct ufs_hba *hba,
{
struct ufshcd_lrb *lrbp = &hba->lrb[task_tag];
struct utp_transfer_req_desc *utrd;
- u32 mask = hwq->max_entries - 1;
__le64 cmd_desc_base_addr;
bool ret = false;
u64 addr, match;
@@ -606,7 +605,10 @@ static bool ufshcd_mcq_sqe_search(struct ufs_hba *hba,
ret = true;
goto out;
}
- sq_head_slot = (sq_head_slot + 1) & mask;
+
+ sq_head_slot++;
+ if (sq_head_slot == hwq->max_entries)
+ sq_head_slot = 0;
}

out:
--
2.7.4