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Re: [Qemu-devel] [PATCH] ide: fix ATAPI read drive structure command
From: |
Alex Williamson |
Subject: |
Re: [Qemu-devel] [PATCH] ide: fix ATAPI read drive structure command |
Date: |
Mon, 02 Jun 2008 08:58:55 -0600 |
Hi Alex,
On Mon, 2008-06-02 at 12:33 +0200, Alexander Graf wrote:
> On May 28, 2008, at 9:48 PM, Alex Williamson wrote:
>
> See below for comments. I haven't tested the patch though, all
> comments are purely based on looking at the patch and mmc-2 spec.
FWIW, I'm working off this draft of the MMC-6 spec that google was able
to find online:
http://www.t10.org/ftp/t10/drafts/mmc6/mmc6r01.pdf
> Great job so far,
Thanks, I still need to look into sg_raw to see how the internal length
field works, but a couple comments...
> > +static void ide_dvd_read_structure(IDEState *s)
> > +{
> > + const uint8_t *packet = s->io_buffer;
> > + uint8_t *buf =s->io_buffer;
> > + int format = packet[7];
> > + int max_len = ube16_to_cpu(packet + 8);
>
>
> These look like function parameters to me.
If you don't think it's too redundant to pass IDEState and the rest,
because I'll need IDEState to call ide_atapi_cmd_*(). Perhaps the
callee could do those, but it looks like it could become ugly pretty
quick.
> > +
> > + memset(buf, 0, max_len);
> > + buf[4] = 1; // DVD-ROM, part version 1
> > + buf[5] = 0xf; // 120mm disc, maximum rate
> > unspecified
>
>
> I guess this means "minimum rate"?
I'm not sure exactly what "Not specified" means, but it's a valid option
in the table I'm looking (Table 409). I assume this has more to do with
writing than reading.
> >
> > + buf[6] = 0; // one layer, embossed data
>
>
> Layer type should be 1 (R/O Layer).
Layer type 1 is a recordable area, which implies DVD-R to me. Embossed
means that it's pre-recorded and read-only, at least as I read it.
> > +
> > + if (!MEDIA_IS_DVD(s)) {
> > + if (format < 0xc0)
> > + ide_atapi_cmd_error(s, SENSE_ILLEGAL_REQUEST,
> > + ASC_INCOMPATIBLE_FORMAT);
> > + else
> > + ide_atapi_cmd_error(s, SENSE_ILLEGAL_REQUEST,
> > +
> > ASC_INV_FIELD_IN_CMD_PACKET);
> > + break;
>
>
> I can't seem to find that in the Spec. In MMC-2 I found:
>
>
> When a READ DVD STRUCTURE Command is issued for CD media, with format
> codes 00h - FEh, the
> command shall be terminated with CHECK CONDITION status, sense key set
> to ILLEGAL REQUEST and the
> additional sense code set to CANNOT READ MEDIUM- INCOMPATIBLE FORMAT.
Here's where I got that interpretation (6.22.2.5):
When the Drive/media combination does not support the specified
Format code, the command shall be terminated with CHECK
CONDITION status and SK/ASC/ASCQ shall be set to ILLEGAL
REQUEST/INVALID FIELD IN CDB.
If a READ DISC STRUCTURE command is issued for media that is not
consistent with this command and the format code is in the range
00h – BFh, the command shall be terminated with CHECK CONDITION
status and SK/ASC/ASCQ shall be set to ILLEGAL REQUEST/CANNOT
READ MEDIUM/INCOMPATIBLE FORMAT.
If there is no medium or an incompatible medium is installed, a
request for Format FFh shall be fulfilled using a Drive specific
media type.
Maybe I shouldn't be basing this on a draft spec? I'll try to play with
sg_raw and clean up the rest. Thanks for the comments,
Alex
--
Alex Williamson HP Open Source & Linux Org.
- Re: [Qemu-devel] [PATCH] ide: fix ATAPI read drive structure command, Alexander Graf, 2008/06/02
- Re: [Qemu-devel] [PATCH] ide: fix ATAPI read drive structure command,
Alex Williamson <=
- Re: [Qemu-devel] [PATCH] ide: fix ATAPI read drive structure command, Alexander Graf, 2008/06/02
- Re: [Qemu-devel] [PATCH] ide: fix ATAPI read drive structure command (v3), Alex Williamson, 2008/06/02
- Re: [Qemu-devel] [PATCH] ide: fix ATAPI read drive structure command (v3), Alex Williamson, 2008/06/02
- Re: [Qemu-devel] [PATCH] ide: fix ATAPI read drive structure command (v3), Alexander Graf, 2008/06/03
- Re: [Qemu-devel] [PATCH] ide: fix ATAPI read drive structure command (v3), Alex Williamson, 2008/06/03
- Re: [Qemu-devel] [PATCH] ide: fix ATAPI read drive structure command (v3), Carlo Marcelo Arenas Belon, 2008/06/03
- Re: [Qemu-devel] [PATCH] ide: fix ATAPI read drive structure command (v3), Anthony Liguori, 2008/06/03
- Re: [Qemu-devel] [PATCH] ide: fix ATAPI read drive structure command (v3), Alex Williamson, 2008/06/04
- Re: [Qemu-devel] [PATCH] ide: fix ATAPI read drive structure command (v3), Anthony Liguori, 2008/06/04
- Re: [Qemu-devel] [PATCH] ide: fix ATAPI read drive structure command (v3), Alex Williamson, 2008/06/04