Re: [PATCH 6/6] ufs: Remove the SCSI timeout handler

From: Alim Akhtar <alim.akhtar@gmail.com>
To: Bart Van Assche <bvanassche@acm.org>
Cc: "Martin K . Petersen" <martin.petersen@oracle.com>,
	"James E . J . Bottomley" <jejb@linux.vnet.ibm.com>,
	linux-scsi@vger.kernel.org, Bean Huo <beanhuo@micron.com>,
	Can Guo <cang@codeaurora.org>, Avri Altman <avri.altman@wdc.com>,
	Stanley Chu <stanley.chu@mediatek.com>,
	Tomas Winkler <tomas.winkler@intel.com>
Subject: Re: [PATCH 6/6] ufs: Remove the SCSI timeout handler
Date: Fri, 27 Dec 2019 06:54:11 +0530	[thread overview]
Message-ID: <CAGOxZ53V1hidM5xsh-KRnNhOUiNFffcozxWM8kxOx2hXm39vqw@mail.gmail.com> (raw)
In-Reply-To: <20191224220248.30138-7-bvanassche@acm.org>

On Wed, Dec 25, 2019 at 3:35 AM Bart Van Assche <bvanassche@acm.org> wrote:
>
> The UFS SCSI timeout handler was needed to compensate that
> ufshcd_queuecommand() could return SCSI_MLQUEUE_HOST_BUSY for a long
> time. Commit a276c19e3e98 ("scsi: ufs: Avoid busy-waiting by eliminating
> tag conflicts") fixed this so the timeout handler is no longer necessary.
>
> See also commit f550c65b543b ("scsi: ufs: implement scsi host timeout handler").
>
> Cc: Bean Huo <beanhuo@micron.com>
> Cc: Can Guo <cang@codeaurora.org>
> Cc: Avri Altman <avri.altman@wdc.com>
> Cc: Stanley Chu <stanley.chu@mediatek.com>
> Cc: Tomas Winkler <tomas.winkler@intel.com>
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
> ---
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>

>  drivers/scsi/ufs/ufshcd.c | 36 ------------------------------------
>  1 file changed, 36 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index edcc137c436b..763e41286a4b 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -7092,41 +7092,6 @@ static void ufshcd_async_scan(void *data, async_cookie_t cookie)
>         ufshcd_probe_hba(hba);
>  }
>
> -static enum blk_eh_timer_return ufshcd_eh_timed_out(struct scsi_cmnd *scmd)
> -{
> -       unsigned long flags;
> -       struct Scsi_Host *host;
> -       struct ufs_hba *hba;
> -       int index;
> -       bool found = false;
> -
> -       if (!scmd || !scmd->device || !scmd->device->host)
> -               return BLK_EH_DONE;
> -
> -       host = scmd->device->host;
> -       hba = shost_priv(host);
> -       if (!hba)
> -               return BLK_EH_DONE;
> -
> -       spin_lock_irqsave(host->host_lock, flags);
> -
> -       for_each_set_bit(index, &hba->outstanding_reqs, hba->nutrs) {
> -               if (hba->lrb[index].cmd == scmd) {
> -                       found = true;
> -                       break;
> -               }
> -       }
> -
> -       spin_unlock_irqrestore(host->host_lock, flags);
> -
> -       /*
> -        * Bypass SCSI error handling and reset the block layer timer if this
> -        * SCSI command was not actually dispatched to UFS driver, otherwise
> -        * let SCSI layer handle the error as usual.
> -        */
> -       return found ? BLK_EH_DONE : BLK_EH_RESET_TIMER;
> -}
> -
>  static const struct attribute_group *ufshcd_driver_groups[] = {
>         &ufs_sysfs_unit_descriptor_group,
>         &ufs_sysfs_lun_attributes_group,
> @@ -7145,7 +7110,6 @@ static struct scsi_host_template ufshcd_driver_template = {
>         .eh_abort_handler       = ufshcd_abort,
>         .eh_device_reset_handler = ufshcd_eh_device_reset_handler,
>         .eh_host_reset_handler   = ufshcd_eh_host_reset_handler,
> -       .eh_timed_out           = ufshcd_eh_timed_out,
>         .this_id                = -1,
>         .sg_tablesize           = SG_ALL,
>         .cmd_per_lun            = UFSHCD_CMD_PER_LUN,


-- 
Regards,
Alim