Re: readcd hangs in blk_execute_rq

[Jens Axboe <axboe@suse.de>]

On Mon, Oct 25 2004, Meelis Roos wrote:
> > > Turned DMA off with hdparm -d 0 /dev/hdc, still the same.
> > > Turned ATAPI DMA support off completely (activated "Use DMA only for
> > > disks" compile option), still the same half-hang.
> >
> > Can I talk you into trying to find out when this broke? You mention
> > 2.4.18 as working, did 2.4.19 break? Narrowing this down as much as
> > possible would be very helpful.
> 
> OK, did some testing.
> 
> 2.4.18, 2.4.19 and 2.4.20 are the same - mostly working. This means that
> it reads non-broken data CD-s with DMA with no problems, but it loses an
> interrupt and disables DMA with a faulty data CD (dmesg below).
> 
> The IDE changes in 2.4.21-pre1 cause DMA to fail at first read attempt
> and all later kernels behave the same.
> 
> The dmesg from 2.4.18 in case of CD read error (with a known faulty cd):
> 
> hdc: command error: status=0x51 { DriveReady SeekComplete Error }
> hdc: command error: error=0x54
> end_request: I/O error, dev 16:00 (hdc), sector 1274020
> ide_dmaproc: chipset supported ide_dma_lostirq func only: 13
> hdc: lost interrupt
> hdc: status timeout: status=0xd0 { Busy }
> hdc: DMA disabled
> hdc: drive not ready for command
> hdc: ATAPI reset complete

Alan, any ideas? IIRC, the 2.4.21-pre1 huge ide update is all your
doing.

-- 
Jens Axboe