On 2020-01-18 23:14, Ming Lei wrote: > diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c > index 5afb0046b12a..f401ba96dcfd 100644 > --- a/drivers/scsi/sd.c > +++ b/drivers/scsi/sd.c > @@ -3380,11 +3380,12 @@ static int sd_probe(struct device *dev) > pm_runtime_set_autosuspend_delay(dev, > sdp->host->hostt->rpm_autosuspend_delay); > } > - device_add_disk(dev, gd, NULL); > + device_add_disk_no_queue_reg(dev, gd); > if (sdkp->capacity) > sd_dif_config_host(sdkp); > > sd_revalidate_disk(gd); > + blk_register_queue(gd); > > if (sdkp->security) { > sdkp->opal_dev = init_opal_dev(sdp, &sd_sec_submit); The effect of changing device_add_disk() into device_add_disk_no_queue_reg() is as follows: - __device_add_disk() skips the elevator_init_mq() call. - __device_add_disk() skips the blk_register_queue() call. The above patch introduces a blk_register_queue() call but no elevator_init_mq() call. Is that perhaps an oversight? Thanks, Bart.