Re: [RESEND PATCH v10 04/10] scsi: ufs: introduce UFSHCD_QUIRK_PRDT_BYTE_GRAN quirk

From: Eric Biggers
Date: Tue Aug 11 2020 - 20:29:26 EST


Hi Alim,

On Sat, Jun 13, 2020 at 08:17:00AM +0530, Alim Akhtar wrote:
> Some UFS host controllers like Exynos uses granularities of PRDT length and
> offset as bytes, whereas others uses actual segment count.
>
> Reviewed-by: Avri Altman <avri.altman@xxxxxxx>
> Signed-off-by: Kiwoong Kim <kwmad.kim@xxxxxxxxxxx>
> Signed-off-by: Alim Akhtar <alim.akhtar@xxxxxxxxxxx>
> ---
> drivers/scsi/ufs/ufshcd.c | 30 +++++++++++++++++++++++-------
> drivers/scsi/ufs/ufshcd.h | 6 ++++++
> 2 files changed, 29 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index ee30ed6cc805..ba093d0d0942 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -2151,8 +2151,14 @@ static int ufshcd_map_sg(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
> return sg_segments;
>
> if (sg_segments) {
> - lrbp->utr_descriptor_ptr->prd_table_length =
> - cpu_to_le16((u16)sg_segments);
> +
> + if (hba->quirks & UFSHCD_QUIRK_PRDT_BYTE_GRAN)
> + lrbp->utr_descriptor_ptr->prd_table_length =
> + cpu_to_le16((sg_segments *
> + sizeof(struct ufshcd_sg_entry)));
> + else
> + lrbp->utr_descriptor_ptr->prd_table_length =
> + cpu_to_le16((u16) (sg_segments));
>
> prd_table = (struct ufshcd_sg_entry *)lrbp->ucd_prdt_ptr;
>
> @@ -3500,11 +3506,21 @@ static void ufshcd_host_memory_configure(struct ufs_hba *hba)
> cpu_to_le32(upper_32_bits(cmd_desc_element_addr));
>
> /* Response upiu and prdt offset should be in double words */
> - utrdlp[i].response_upiu_offset =
> - cpu_to_le16(response_offset >> 2);
> - utrdlp[i].prd_table_offset = cpu_to_le16(prdt_offset >> 2);
> - utrdlp[i].response_upiu_length =
> - cpu_to_le16(ALIGNED_UPIU_SIZE >> 2);
> + if (hba->quirks & UFSHCD_QUIRK_PRDT_BYTE_GRAN) {
> + utrdlp[i].response_upiu_offset =
> + cpu_to_le16(response_offset);
> + utrdlp[i].prd_table_offset =
> + cpu_to_le16(prdt_offset);
> + utrdlp[i].response_upiu_length =
> + cpu_to_le16(ALIGNED_UPIU_SIZE);
> + } else {
> + utrdlp[i].response_upiu_offset =
> + cpu_to_le16(response_offset >> 2);
> + utrdlp[i].prd_table_offset =
> + cpu_to_le16(prdt_offset >> 2);
> + utrdlp[i].response_upiu_length =
> + cpu_to_le16(ALIGNED_UPIU_SIZE >> 2);
> + }
>
> ufshcd_init_lrb(hba, &hba->lrb[i], i);
> }

Isn't this patch missing an update to ufshcd_print_trs()? It uses
->prd_table_length as the number of segments, not the number of bytes.

- Eric