[PATCH 1/1] Revert "scsi: ufs: Use pre-calculated offsets in ufshcd_init_lrb()"

[PATCH 1/1] Revert "scsi: ufs: Use pre-calculated offsets in ufshcd_init_lrb()"

[ed.tsai]

From: Ed Tsai <ed.tsai@mediatek.com>

This reverts commit d5130c5a093257aa4542aaded8034ef116a7624a.

The offsets stored in utp_transfer_req_desc are in double words on
hosts without UFSHCD_QUIRK_PRDT_BYTE_GRAN, using them directly to
compute ucd_rsp_dma_addr and ucd_prdt_dma_addr results in incorrect
DMA addresses. The manual offsetof(struct utp_transfer_cmd_desc, ...)
calculations always yield correct byte offsets regardless of the quirk
and should be used instead.

Note that these DMA addresses are only used in ufshcd_print_tr() for
error logging, so the impact is limited to misleading error logs.

Fixes: d5130c5a0932 ("scsi: ufs: Use pre-calculated offsets in ufshcd_init_lrb()")
Signed-off-by: Ed Tsai <ed.tsai@mediatek.com>
---
 drivers/ufs/core/ufshcd.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 4805e40ed4d7..3df2b44111cc 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -2971,8 +2971,9 @@ static void ufshcd_init_lrb(struct ufs_hba *hba, struct scsi_cmnd *cmd)
 	struct utp_transfer_req_desc *utrdlp = hba->utrdl_base_addr;
 	dma_addr_t cmd_desc_element_addr =
 		hba->ucdl_dma_addr + i * ufshcd_get_ucd_size(hba);
-	u16 response_offset = le16_to_cpu(utrdlp[i].response_upiu_offset);
-	u16 prdt_offset = le16_to_cpu(utrdlp[i].prd_table_offset);
+	u16 response_offset = offsetof(struct utp_transfer_cmd_desc,
+				       response_upiu);
+	u16 prdt_offset = offsetof(struct utp_transfer_cmd_desc, prd_table);
 	struct ufshcd_lrb *lrb = scsi_cmd_priv(cmd);
 
 	lrb->utr_descriptor_ptr = utrdlp + i;
-- 
2.45.2

Re: [PATCH 1/1] Revert "scsi: ufs: Use pre-calculated offsets in ufshcd_init_lrb()"

[Bart Van Assche]

On 4/23/26 11:35 PM, ed.tsai@mediatek.com wrote:
> Note that these DMA addresses are only used in ufshcd_print_tr() for
> error logging, so the impact is limited to misleading error logs.

Instead of fixing these offsets, please remove the ucd_rsp_dma_addr and
ucd_prdt_dma_addr members from struct ufshcd_lrb.

Thanks,

Bart.

Re: [PATCH 1/1] Revert "scsi: ufs: Use pre-calculated offsets in ufshcd_init_lrb()"

[Ed Tsai (蔡宗軒)]

On Fri, 2026-04-24 at 15:55 -0700, Bart Van Assche wrote:
> 
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
> 
> 
> On 4/23/26 11:35 PM, ed.tsai@mediatek.com wrote:
> > Note that these DMA addresses are only used in ufshcd_print_tr()
> > for
> > error logging, so the impact is limited to misleading error logs.
> 
> Instead of fixing these offsets, please remove the ucd_rsp_dma_addr
> and
> ucd_prdt_dma_addr members from struct ufshcd_lrb.
> 
> Thanks,
> 
> Bart.

Sounds good, I will send a new patch. Thanks.