Re: PATA DMA problem leading to kernel panic on reading movie DVDs

[Martin Lottermoser <Martin.Lottermoser@t-online.de>]

Hello,

On Tue, May 19, 2009 at 05:19:35PM +0200, Bartlomiej Zolnierkiewicz wrote:
> Subject: [PATCH] ide: fix 40-wire cable detection for TSST SH-S202* ATAPI devices

I'm sorry, but that also generated a panic, looking identical to the
behaviour as for the unpatched 2.6.30-rc6.

After booting the patched kernel, the syslog file showed:

  hdc: UDMA/66 mode selected

"hdparm -I" reported that the drive was set to "udma4". On accessing the DVD,
the kernel panicked. Here's the main output from netconsole:

  hdc: cdrom_decode_status: error=0x40 <3>{ LastFailedSense=0x04 }
  ide: failed opcode was: unknown
  hdc: DMA disabled
  ------------[ cut here ]------------
  kernel BUG at drivers/ide/ide-io.c:872!
  invalid opcode: 0000 [#1]
  last sysfs file: /sys/devices/pci0000:00/0000:00:1f.1/ide1/1.0/block/hdc/size

After booting the kernel and before doing the test I had checked with
"uname -a" that this really was the newly compiled kernel. After reboot I
checked that ide-iops.o existed and had a modification time later than the
moment I applied your patch. Also, the new vmlinuz is 64 bytes shorter than
the unpatched one. Therefore I don't think I made some silly mistake which
led to the patch being ignored.

The offer for testing patches remains open :-).

Regards,
Martin Lottermoser
--
Martin Lottermoser             Martin.Lottermoser at _REMOVE_t-online.de
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