lkml.org 
[lkml]   [2023]   [Jun]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v1 1/1] ufs: mcq: Fix the variable wraparound logic
Date
If the hwq's queue depth is not a multiple of 4s, the
logic used for wrapping around the increase-by-1 sq_head_slot
variable in ufshcd_mcq_sqe_search() will give an incorrect
result because the binary expression of the mask is not
a uniform of all 1s.

Signed-off-by: Bao D. Nguyen <quic_nguyenb@quicinc.com>
---
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 66ac02e..8e5bc88 100644
--- a/drivers/ufs/core/ufs-mcq.c
+++ b/drivers/ufs/core/ufs-mcq.c
@@ -585,7 +585,6 @@ 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;
@@ -610,7 +609,10 @@ 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
\
 
 \ /
  Last update: 2023-06-01 13:29    [W:0.038 / U:0.192 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site