On Thu, 2018-01-18 at 17:22 +0100, Jack Wang wrote:
> From: Jack Wang <jinpu.wang@xxxxxxxxxxxxxxxx>
>
> The check_events interface was added for check if device changes,
> mainly for device is removable eg. CDROM
>
> In sd_open, it checks if device is removable then check_disk_change.
>
> when the device is not removable, we can simple succeeds the call
> without send TUR.
>
> Signed-off-by: Jack Wang <jinpu.wang@xxxxxxxxxxxxxxxx>
> ---
> drivers/scsi/sd.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
> index ab75ebd..773ce81 100644
> --- a/drivers/scsi/sd.c
> +++ b/drivers/scsi/sd.c
> @@ -1576,6 +1576,10 @@ static unsigned int sd_check_events(struct
> gendisk *disk, unsigned int clearing)
> sdp = sdkp->device;
> SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp,
> "sd_check_events\n"));
>
> + if (!sdp->removable) {
> + retval = 0;
> + goto out;
> + }
This looks like very much the wrong place to fix whatever problem
you're seeing is. We could simply avoid setting up the events work
function in genhd.c:device_add_disk(), which would be way more
efficient. However, I think some devices do require being probed
occasionally with a TUR because its the only way SCSI gets AENs (not
that we make much use of them).
So first of all, what's the actual problem?
James
