From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH] cdrom: support devices that have check_events but not media_changed Date: Mon, 31 Jan 2011 11:12:44 +0100 Message-ID: <20110131101244.GA7459@htj.dyndns.org> References: <1291838262-21274-1-git-send-email-tj@kernel.org> <1291838262-21274-8-git-send-email-tj@kernel.org> <4D44BE3E.5080107@simon.arlott.org.uk> <4D44BF64.4060205@simon.arlott.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <4D44BF64.4060205@simon.arlott.org.uk> Sender: linux-kernel-owner@vger.kernel.org To: Simon Arlott Cc: axboe@kernel.dk, jeff@garzik.org, linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, kay.sievers@vrfy.org, jack@suse.cz, James.Bottomley@HansenPartnership.com List-Id: linux-ide@vger.kernel.org Hello, On Sun, Jan 30, 2011 at 01:31:16AM +0000, Simon Arlott wrote: > 93aae17af1172c40c6f74b7294e93a90c3cfaa5d replaced the media_changed op > with the check_events op in drivers/scsi/sr.c > > All users that check for the CDC_MEDIA_CHANGED capability try both > the check_events op and the media_changed op, but register_cdrom() > was requiring media_changed. > > This patch fixes the capability checking and removes a redundant > check that media_changed != NULL. > > The cdrom_select_disc ioctl is also using the two operations, so > they should be required for CDC_SELECT_DISC too. First of all, thanks a lot for fixing this. Just minor nits below. > diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c > index 14033a3..4716d76 100644 > --- a/drivers/cdrom/cdrom.c > +++ b/drivers/cdrom/cdrom.c > @@ -409,7 +409,9 @@ int register_cdrom(struct cdrom_device_info *cdi) > } > > ENSURE(drive_status, CDC_DRIVE_STATUS ); > - ENSURE(media_changed, CDC_MEDIA_CHANGED); > + if (cdo->check_events == NULL && cdo->media_changed == NULL) { > + *change_capability = ~(CDC_MEDIA_CHANGED | CDC_SELECT_DISC); > + } Can we lose the unnecessary {}? > ENSURE(tray_move, CDC_CLOSE_TRAY | CDC_OPEN_TRAY); > ENSURE(lock_door, CDC_LOCK); > ENSURE(select_speed, CDC_SELECT_SPEED); > @@ -1471,7 +1473,7 @@ int cdrom_media_changed(struct cdrom_device_info *cdi) > /* This talks to the VFS, which doesn't like errors - just 1 or 0. > * Returning "0" is always safe (media hasn't been changed). Do that > * if the low-level cdrom driver dosn't support media changed. */ > - if (cdi == NULL || cdi->ops->media_changed == NULL) > + if (cdi == NULL) This change is probably not necessary as cdrom_media_changed() is only called from drivers which implement media_changed. I don't think it's gonna break anything but the whole media_changed stuff is scheduled for removal anyway, so I think it would be better to keep the changes minimal. Thank you. -- tejun