Re: 2.4.21-rc: lost interrupt wgen usinf atapi cdrom-drive

[Michael Reincke]

On Tue, 2003-05-13 at 09:37, Michael Reincke wrote:
> On Tue, 2003-05-13 at 09:29, Michael Reincke wrote:
> > On Tue, 2003-05-13 at 08:21, Andrey Borzenkov wrote:
> > > > i upgraded the linux kernel of my computer from 2.4.21-pre4 to
> > > > 2.4.21-rc2 and got the following messages in syslog when using my
> > > > atapi-cdrom drive:
> > > > May 12 09:42:52 pcew80 kernel: hdc: DMA interrupt recovery
> > > > May 12 09:42:52 pcew80 kernel: hdc: lost interrupt
> > > > May 12 09:42:52 pcew80 kernel: hdc: status timeout: status=0xd0 { Busy }
> > > > May 12 09:42:52 pcew80 kernel: hdc: status timeout: error=0x00
> > > > May 12 09:42:52 pcew80 kernel: hdc: DMA disabled
> > > > May 12 09:42:52 pcew80 kernel: hdc: drive not ready for command
> > > > May 12 09:42:52 pcew80 kernel: hdc: ATAPI reset complete
> > > 
> > > 
> > > It smells like ide_do_request forgets to enable interrupts when
> > > request queue is empty.
> > > 
> > > drivers/ide/ide-io.c:
> > > 
> > > void ide_do_request (ide_hwgroup_t *hwgroup, int masked_irq)
> > >                         hwgroup->busy = 0;
> > > 
> > > Ironically it does not release ide_intr_lock in this case but we
> > > are not on m68k so we do not care :)
> > > 
> > > Could you please try to add local_irq_enable() before ide_release_lock() above and see if it helps?
> > > It has been reported to have fixed fix problems for other people. OTOH
> > > I did have sevral hard lockups with this so there may be more subtle
> > > problems issues.
> > The hangs and timeouts and total blocking of the cdrom drive seems to be
> > away, but the lost interrupt messages are still there.
> > But have in mind I've only a quick test so far.
> 
> Bad news the hangs and timeout are still there!

The problem is vanishing when disabling
IO-APIC support on uniprocessors             
-- 
Michael Reincke, NUT Team 2 (Software Build Management)

STN ATLAS Elektronik GmbH, Bremen (Germany)
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