cd(4) vs bluray and cdda (dae) on ahci(4) and siis(4)

[Ulrich Spörlein]

On Thu, 06.08.2009 at 20:45:10 +0200, Juergen Lock wrote:
> Hi!
> 
>  So I put the problematic optical drive on a siis pcie card now because
> I wanted to play with esata too which seems to be kinda broken on the
> jmicron that I used before at least with _this_ esata drive (hw issue
> most likely, has been reported by users of other OSes too) - and I
> noticed two things:
> 
> 1. cd(4) (which the new ahci and siis drivers now also use) fails to do
> any reads when a drive fails the read toc command as seems to happen
> with bluray (data) discs at least; I was able to work around this
> by moving the bailout: label up a few lines in scsi_cd.c:cdcheckmedia():
> 
> Index: sys/cam/scsi/scsi_cd.c
> @@ -2868,12 +2868,18 @@
>  	}
>  
>  	softc->flags |= CD_FLAG_VALID_TOC;
> +
> +bailout:
>  	softc->disk->d_maxsize = DFLTPHYS;
>  	softc->disk->d_sectorsize = softc->params.blksize;
>  	softc->disk->d_mediasize =
>  	    (off_t)softc->params.blksize * softc->params.disksize;
>  
> +/* if
>  bailout:
> + * is here read requests will fail when the toc cant be read although
> + * CD_FLAG_VALID_MEDIA is set.
> + */
>  
>  	/*
>  	 * We unconditionally (re)set the blocksize each time the
> 
>  (I say work around because I don't know if there might be stuff
> somewhere that depends on the old behaviour, although thats probably
> unlikely; also acd(4) seems to behave similarly.)

T H A N K   Y O U !

Hi Juergen, this nice little patch lets my USB/Firewire attached Plextor
drive read "pressed" DVD media, where it failed before. I have mentioned
this in the past, but due to the esoteric nature of this problem failed
to attract enough attention.

http://lists.freebsd.org/pipermail/freebsd-usb/2007-July/003730.html
http://docs.freebsd.org/cgi/getmsg.cgi?fetch=644449+0+archive/2007/freebsd-current/20070812.freebsd-current

So this is not only related to Bluray, but plain DVD media is affected
too (at least for some drives ...)

Hopefully this can get committed some time soon...

Regards,
Uli