Re: [PATCH v2 2/4] scsi: ufs: Let UPIU completion trace print RSP UPIU header

[Can Guo]

On 2021-05-31 18:43, Bean Huo wrote:
> From: Bean Huo <beanhuo@xxxxxxxxxx>
>
> The current UPIU completion event trace still prints the COMMAND UPIU
> header, rather than the RSP UPIU header. This makes UPIU command trace
> useless in problem shooting in case we receive a trace log from the
> customer/field.
>
> There are two important fields in RSP UPIU:
>  1. The response field, which indicates the UFS defined overall success
>     or failure of the series of Command, Data and RESPONSE UPIU’s that
>     make up the execution of a task.
>  2. The Status field, which contains the command set specific status 
> for
>     a specific command issued by the initiator device.
>
> Before this patch, the UPIU paired trace events:
>
> ufshcd_upiu: send_req: fe3b0000.ufs: HDR:01 20 00 1c 00 00 00 00 00 00
> 00 00, CDB:3b e1 00 00 00 00 00 00 30 00 00 00 00 00 00 00
> ufshcd_upiu: complete_rsp: fe3b0000.ufs: HDR:01 20 00 1c 00 00 00 00
> 00 00 00 00, CDB:3b e1 00 00 00 00 00 00 30 00 00 00 00 00 00 00
>
> After the patch:
>
> ufshcd_upiu: send_req: fe3b0000.ufs: HDR:01 20 00 1c 00 00 00 00 00 00
> 00 00, CDB:3b e1 00 00 00 00 00 00 30 00 00 00 00 00 00 00
> ufshcd_upiu: complete_rsp: fe3b0000.ufs: HDR:21 00 00 1c 00 00 00 00
> 00 00 00 00, CDB:3b e1 00 00 00 00 00 00 30 00 00 00 00 00 00 00
>
> Signed-off-by: Bean Huo <beanhuo@xxxxxxxxxx>
> ---
>  drivers/scsi/ufs/ufshcd.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 85590d3a719e..c5754d5486c9 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -302,11 +302,17 @@ static void ufshcd_add_cmd_upiu_trace(struct
> ufs_hba *hba, unsigned int tag,
>  				      enum ufs_trace_str_t str_t)
>  {
>  	struct utp_upiu_req *rq = hba->lrb[tag].ucd_req_ptr;
> +	struct utp_upiu_header *header;
>
>  	if (!trace_ufshcd_upiu_enabled())
>  		return;
>
> -	trace_ufshcd_upiu(dev_name(hba->dev), str_t, &rq->header, 
> &rq->sc.cdb,
> +	if (str_t == UFS_CMD_SEND)
> +		header = &rq->header;
> +	else
> +		header = &hba->lrb[tag].ucd_rsp_ptr->header;
> +
> +	trace_ufshcd_upiu(dev_name(hba->dev), str_t, header, &rq->sc.cdb,
>  			  UFS_TSF_CDB);
>  }

Reviewed-by: Can Guo <cang@xxxxxxxxxxxxxx>