Fwd: Re: Fwd: [MPlayer-users] SCSI emulation

[H}kan Hjort]

Sun Jan 05 2003, Bob Lockie wrote:
> H}kan Hjort wrote:
> >Sun Jan 05 2003, Bob Lockie wrote:
> >>H}kan Hjort wrote:
> >>>Sat Jan 04 2003, Bob Lockie wrote:
[snip]
> >>>># hdparm -d /dev/sr1
> >>>>/dev/sr1 not supported by hdparm
> >>>>How do I enable DMA for an emulated IDE DVD drive?
> >>>>
> >>>Changing the DMA status is done by reprogramming the IDE chipset/bus,
> >>>so even when it's using ide-scsi emulation you need to use the underlying
> >>>ide node to change it.  So /dev/hdc for you, and then read/test on the
> >>>/dev/sr1 node.  Your sure sr1 is the DVD?
> >>>
> >>That was my guess but /dev/hdc disappears when I use SCSI emulation.
> >># ll /dev/hdc
> >>ls: /dev/hdc: No such file or directory
> >>
> >A side effect of using devfs perhaps?  There should be some trace of
> >the ide device still, should there not?  Or there will be a general
> >problem with things like DMA!
> >
> The only thing I could find is in /proc but I can't check DMA for hdc there.
> 
> #hdparm /proc/ide/hdc
> /proc/ide/hdc not supported by hdparm
> 
> Should I look somewhere else?
> 
Yes under /dev.
 /dev/ide/host0/bus1/target0/lun0/generic
or some other thing under /dev/ide/host0/bus1/target0/lun0/

You can read the status (just read) in /proc/ide/hdc/settings

[snip]
> >>lr-xr-xr-x    1 root     root            8 Jan  4 07:00 /dev/dvd -> 
> >>/dev/sr1
> >>brw-rw----    1 root     cdrecording  11,   1 Dec 31  1969 /dev/dvd
> >>
> >>and for normal IDE
> >>lr-xr-xr-x    1 root     root           10 Jan  4 15:12 /dev/dvd -> 
> >>/dev/cdrom
> >>brw-rw-rw-    1 root     root      22,   0 Dec 31  1969 /dev/dvd
> >>
> >>So unless you are a member of the cdrecording group you don't have 
> >>'rw' permissions in the SCSI emulation case.
> >>
> No, everything is owned by root and group root:
> 
> When SCSI emulation is enabled.
> 
> # ll /dev/dvd
> lr-xr-xr-x    1 root     root            8 Jan  5 12:57 /dev/dvd -> 
> /dev/sr1
> 
> # ll /dev/cdrom
> lr-xr-xr-x    1 root     root           13 Jan  5 12:53 /dev/cdrom -> 
> cdroms/cdrom0
> 
> # ll /dev/cdroms/cdrom0
> lr-xr-xr-x    1 root     root           34 Dec 31  1969 
> /dev/cdroms/cdrom0 -> ../scsi/host0/bus0/target1/lun0/cd
> 
> 
But these are just links, it's the actuall device node that matters.
Here that would be /dev/scsi/host0/bus0/target1/lun0/cd
and for the ide case /dev/ide/host0/bus1/target0/lun0/cd.

> >Another thing is that for all the logs reading sector (lba) 512 and later
> >failed.
> >
> Did even the direct IDE show that?

Yes.

> Maybe I have a hardware problem.
> 
No that's probably just the CSS protection.  It just seemed a bit
early to me though.

So is there still some problem?  Or was this all just configure / 
setup problmes?

-- 
Håkan Hjort
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