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

From: Eric Biggers <[email-masked]>
Date: Tue, 11 Aug 2020 17:29:20 -0700

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 <[email-masked]>
> Signed-off-by: Kiwoong Kim <[email-masked]>
> Signed-off-by: Alim Akhtar <[email-masked]>
> ---
>  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

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