| Message ID | e6e8559eee9626afa38f88e18080398e7296e1bb.1685617541.git.quic_nguyenb@quicinc.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v1,1/1] ufs: mcq: Fix the variable wraparound logic | expand |
Please ignore this duplicate patch. My apologies. Thanks, Bao On 6/1/2023 4:27 AM, Bao D. Nguyen wrote: > 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:
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:
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(-)