SATA DVD issue...

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hello!
I am trying to use a SATA DVD burner on a Marvell Kirkwood based
platform, kernel is currently based on vanilla 2.6.34 with only board
specific patches.

SATA in general works just fine with harddisks.

But when I attach my DVD drive any data read or write access triggers a
BUG() in libata-sff.c:

ata_bmdma_qc_issue():
...
        /* see ata_dma_blacklisted() */
        BUG_ON((ap->flags & ATA_FLAG_PIO_POLLING) &&
               qc->tf.protocol == ATAPI_PROT_DMA);
...

Command access (e.g. to eject the media or to erase a R/W disc) do work.

My knowledge about ATA and SATA is quite limited so I cannot really
interpret this issue.

After some looking around and with the hint in the comment I tried
blacklisting my drive, so I added an entry to libata-core.c:

        { "HL-DT-ST DVDRAM GH22LS50", "TL01",           ATA_HORKAGE_NODMA },

Now the drive works but it is awefully slow - reading just a little over
1MB/s - well, without DMA mode this is quite expectable.

I suspect that the Marvell SATA host driver should be OK and is not in
fault - it is widely used in PCI setups and the SOC variant does almost
not differ. And I also suspect that the above "fix" is not the best way
to do it.
I also tried the same driver with a USB-SATA connector (I do not have a
SATA PC at hand right now) and there it behaves pretty normal with 5 to
10 times higher read rates.


I would be more than happy if someone could help me diagnosing and
especially fixing this problem. If I can give more information or try
different things on the board just let know!

Many thanks in advance!

Cheers
  nils

-- 
kernel concepts GbR      Tel: +49-271-771091-12
Sieghuetter Hauptweg 48  Fax: +49-271-771091-19
D-57072 Siegen           Mob: +49-176-21024535
http://www.kernelconcepts.de
--
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Filesystems]     [Linux SCSI]     [Linux RAID]     [Git]     [Kernel Newbies]     [Linux Newbie]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Samba]     [Device Mapper]

  Powered by Linux