Re: [PATCH v2 14/20] scsi: ufs: Introduce ufshcd_release_scsi_cmd()

[Adrian Hunter <adrian.hunter@intel.com>]

On 19/11/2021 21:57, Bart Van Assche wrote:
> The only functional change in this patch is that scsi_done() is now called
> after ufshcd_release() and ufshcd_clk_scaling_update_busy().
> 
> The next patch in this series will introduce a call to
> ufshcd_release_scsi_cmd() in the abort handler.
> 
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
> ---
>  drivers/scsi/ufs/ufshcd.c | 27 +++++++++++++++------------
>  1 file changed, 15 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 03f4772fc2e2..39dcf997a638 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -5248,6 +5248,18 @@ static irqreturn_t ufshcd_uic_cmd_compl(struct ufs_hba *hba, u32 intr_status)
>  	return retval;
>  }
>  
> +/* Release the resources allocated for processing a SCSI command. */
> +static void ufshcd_release_scsi_cmd(struct ufs_hba *hba,
> +				    struct ufshcd_lrb *lrbp)
> +{
> +	struct scsi_cmnd *cmd = lrbp->cmd;
> +
> +	scsi_dma_unmap(cmd);
> +	lrbp->cmd = NULL;	/* Mark the command as completed. */
> +	ufshcd_release(hba);
> +	ufshcd_clk_scaling_update_busy(hba);
> +}

That seems to leave a gap in the handling of tracing.

Wouldn't we be better served to tweak the monitoring code
in __ufshcd_transfer_req_compl() and then use
 __ufshcd_transfer_req_compl()? i.e.

	result = ufshcd_transfer_rsp_status(hba, lrbp);
	if (unlikely(!result && ufshcd_should_inform_monitor(hba, lrbp)))
		ufshcd_update_monitor(hba, lrbp);


> +
>  /**
>   * __ufshcd_transfer_req_compl - handle SCSI and query command completion
>   * @hba: per adapter instance
> @@ -5258,9 +5270,7 @@ static void __ufshcd_transfer_req_compl(struct ufs_hba *hba,
>  {
>  	struct ufshcd_lrb *lrbp;
>  	struct scsi_cmnd *cmd;
> -	int result;
>  	int index;
> -	bool update_scaling = false;
>  
>  	for_each_set_bit(index, &completed_reqs, hba->nutrs) {
>  		lrbp = &hba->lrb[index];
> @@ -5270,26 +5280,19 @@ static void __ufshcd_transfer_req_compl(struct ufs_hba *hba,
>  			if (unlikely(ufshcd_should_inform_monitor(hba, lrbp)))
>  				ufshcd_update_monitor(hba, lrbp);
>  			ufshcd_add_command_trace(hba, index, UFS_CMD_COMP);
> -			result = ufshcd_transfer_rsp_status(hba, lrbp);
> -			scsi_dma_unmap(cmd);
> -			cmd->result = result;
> -			/* Mark completed command as NULL in LRB */
> -			lrbp->cmd = NULL;
> +			cmd->result = ufshcd_transfer_rsp_status(hba, lrbp);
> +			ufshcd_release_scsi_cmd(hba, lrbp);
>  			/* Do not touch lrbp after scsi done */
>  			scsi_done(cmd);
> -			ufshcd_release(hba);
> -			update_scaling = true;
>  		} else if (lrbp->command_type == UTP_CMD_TYPE_DEV_MANAGE ||
>  			lrbp->command_type == UTP_CMD_TYPE_UFS_STORAGE) {
>  			if (hba->dev_cmd.complete) {
>  				ufshcd_add_command_trace(hba, index,
>  							 UFS_DEV_COMP);
>  				complete(hba->dev_cmd.complete);
> -				update_scaling = true;
> +				ufshcd_clk_scaling_update_busy(hba);
>  			}
>  		}
> -		if (update_scaling)
> -			ufshcd_clk_scaling_update_busy(hba);
>  	}
>  }
>  
>