On 2019-12-24 05:01, Stanley Chu wrote:
> Currently UFS driver has ufshcd_scsi_block_requests() with
> reference counter mechanism to avoid possible racing of blocking and
> unblocking requests flow. Unify all users in UFS driver to use the
> same function.
>
> Signed-off-by: Stanley Chu <stanley.chu@xxxxxxxxxxxx>
> ---
> drivers/scsi/ufs/ufshcd.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index ed02a70..b6b9665 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -5177,7 +5177,7 @@ static void ufshcd_exception_event_handler(struct work_struct *work)
> hba = container_of(work, struct ufs_hba, eeh_work);
>
> pm_runtime_get_sync(hba->dev);
> - scsi_block_requests(hba->host);
> + ufshcd_scsi_block_requests(hba);
> err = ufshcd_get_ee_status(hba, &status);
> if (err) {
> dev_err(hba->dev, "%s: failed to get exception status %d\n",
> @@ -5191,7 +5191,7 @@ static void ufshcd_exception_event_handler(struct work_struct *work)
> ufshcd_bkops_exception_event_handler(hba);
>
> out:
> - scsi_unblock_requests(hba->host);
> + ufshcd_scsi_unblock_requests(hba);
> pm_runtime_put_sync(hba->dev);
> return;
> }
Hi Stanley,
>From the SCSI core:
void scsi_block_requests(struct Scsi_Host *shost)
{
shost->host_self_blocked = 1;
}
In other words, neither scsi_block_requests() nor
ufshcd_scsi_block_requests() wait for ongoing ufshcd_queuecommand()
calls to finish. Is it required to wait for these calls to finish before
exceptions are handled? If not, can the scsi_block_requests() and
scsi_unblock_requests() calls be left out? If it is required to wait for
ongoing ufshcd_queuecommand() calls to finish then I think the
scsi_block_requests() and scsi_unblock_requests() will have to be
changed into something else.
Thanks,
Bart.
