On 18/05/23 01:31, Bart Van Assche wrote:
> ufshcd_queuecommand() may be called two times in a row for a SCSI
> command before it is completed. Hence make the following changes:
> - In the functions that submit a command, do not check the old value of
> lrbp->cmd nor clear lrbp->cmd in error paths.
> - In ufshcd_release_scsi_cmd(), do not clear lrbp->cmd.
>
> See also scsi_send_eh_cmnd().
>
> This patch prevents that the following appears if a command times out:
>
> WARNING: at drivers/ufs/core/ufshcd.c:2965 ufshcd_queuecommand+0x6f8/0x9a8
> Call trace:
> ufshcd_queuecommand+0x6f8/0x9a8
> scsi_send_eh_cmnd+0x2c0/0x960
> scsi_eh_test_devices+0x100/0x314
> scsi_eh_ready_devs+0xd90/0x114c
> scsi_error_handler+0x2b4/0xb70
> kthread+0x16c/0x1e0
>
> Fixes: 5a0b0cb9bee7 ("[SCSI] ufs: Add support for sending NOP OUT UPIU")
> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
A couple of minor comments, nevertheless:
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> ---
> drivers/ufs/core/ufshcd.c | 5 -----
> 1 file changed, 5 deletions(-)
>
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index 37337d411466..68d9e24fac98 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -2928,7 +2928,6 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
> (hba->clk_gating.state != CLKS_ON));
>
> lrbp = &hba->lrb[tag];
> - WARN_ON(lrbp->cmd);
AFAICT eh uses the same struct i.e. lrbp->cmd => lrbp->cmd == cmd in that case
> lrbp->cmd = cmd;
> lrbp->task_tag = tag;
> lrbp->lun = ufshcd_scsi_to_upiu_lun(cmd->device->lun);
> @@ -2944,7 +2943,6 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
>
> err = ufshcd_map_sg(hba, lrbp);
> if (err) {
> - lrbp->cmd = NULL;
> ufshcd_release(hba);
> goto out;
> }
> @@ -5405,7 +5403,6 @@ static void ufshcd_release_scsi_cmd(struct ufs_hba *hba,
> 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);
> }
> @@ -7020,7 +7017,6 @@ static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba,
> down_read(&hba->clk_scaling_lock);
>
> lrbp = &hba->lrb[tag];
> - WARN_ON(lrbp->cmd);
> lrbp->cmd = NULL;
> lrbp->task_tag = tag;
> lrbp->lun = 0;
> @@ -7192,7 +7188,6 @@ int ufshcd_advanced_rpmb_req_handler(struct ufs_hba *hba, struct utp_upiu_req *r
> down_read(&hba->clk_scaling_lock);
>
> lrbp = &hba->lrb[tag];
> - WARN_ON(lrbp->cmd);
> lrbp->cmd = NULL;
> lrbp->task_tag = tag;
> lrbp->lun = UFS_UPIU_RPMB_WLUN;
>
Currently the reserved tag is not used for SCSI cmds but
there is also a WARN_ON(lrbp->cmd) in ufshcd_exec_dev_cmd()
