Bug 7492 - parport doesn't work if DMA is used
Summary: parport doesn't work if DMA is used
Status: RESOLVED OBSOLETE
Alias: None
Product: Drivers
Classification: Unclassified
Component: Parallel (show other bugs)
Hardware: i386 Linux
: P2 normal
Assignee: drivers_parallel
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2006-11-11 00:45 UTC by Stas Sergeev
Modified: 2015-02-19 15:07 UTC (History)
7 users (show)

See Also:
Kernel Version: 2.6.27
Subsystem:
Regression: No
Bisected commit-id:


Attachments
dmesg (38.32 KB, text/plain)
2008-12-10 01:48 UTC, Stas Sergeev
Details

Description Stas Sergeev 2006-11-11 00:45:47 UTC
Most recent kernel where this bug did not occur:
no idea

Distribution:
FC6

Hardware Environment:
Gigabyte GA-K8N-SLI mobo with nForce4 chipset.

Software Environment:
Problem Description:
The parport_pc module uses the DMA on my chipset, disregarding
its module params. And when it does so, the parport doesn't
seem to work right. If I try to print something, the printer
only prints a garbage and spoils the paper. While it is a bug
that I can't disable the DMA with the modparams, the DMA itself
should work too.
Let me know if any additional info is needed.

Steps to reproduce:
Get the mobo mentioned above and try to print something
on a parallel printer. You'll have the bad results.
Comment 1 mjacek 2007-01-09 09:35:22 UTC
Is this on 64-bit kernel? If yes, read
http://bugzilla.kernel.org/show_bug.cgi?id=5832
Maybe it's close....
Comment 2 Natalie Protasevich 2007-07-05 01:35:42 UTC
Anything new with this problem? still exists with new kernels?
Thanks.
Comment 3 Stas Sergeev 2007-07-20 12:16:08 UTC
Sorry if I forget to answer this.
Its still the same with 2.6.22.
Comment 4 Andrew Morton 2007-08-02 13:15:02 UTC
Please provide the exact module args whcih you are using.
Comment 5 Stas Sergeev 2007-08-02 13:28:07 UTC
> Please provide the exact module args whcih you are using.
None.
They do not work anyway.
The details about why they do not
work and what have been done in an
attempt to get them to work, see Bug #7491.
Comment 6 Stas Sergeev 2007-08-02 13:29:56 UTC
And if someone is wondering, here is the dmesg:
http://bugzilla.kernel.org/attachment.cgi?id=12156&action=view
Comment 7 Andrew Morton 2007-08-02 13:38:32 UTC
*what* "do not work anyway"?

You've obviously attempted to use some module parameter to disable DMA
and found that it failed to do so.  OK, what was that module parameter?

And sure, fixing the module-parameter handling won't fix the DMA problem, 
but one thing at a time..
Comment 8 Stas Sergeev 2007-08-02 13:49:10 UTC
> *what* "do not work anyway"?
The modparams of parport_pc.
irq= dma= whatever.

> You've obviously attempted to use some module parameter to disable DMA
> and found that it failed to do so.
And so I created the Bug #7491.

> OK, what was that module parameter?
"dma=none" mainly, but please visit the appropriate
report itself for more info.

> And sure, fixing the module-parameter handling won't fix the DMA problem, 
> but one thing at a time..
Yes, so that's why I have two separate reports
opened for that and trying to prevent people
from mixing these problems together. :)
Comment 9 Stas Sergeev 2007-08-02 13:56:17 UTC
OK, as you are probably only reading the
email notifications, it does not provide
you with the direct link to "Bug #7491"
(whereas the web interface does) so here it is:
http://bugzilla.kernel.org/show_bug.cgi?id=7491
Comment 10 Anonymous Emailer 2007-08-02 13:57:00 UTC
Reply-To: akpm@linux-foundation.org

On Thu,  2 Aug 2007 13:42:59 -0700 (PDT)
bugme-daemon@bugzilla.kernel.org wrote:

> > And sure, fixing the module-parameter handling won't fix the DMA problem, 
> > but one thing at a time..
> Yes, so that's why I have two separate reports
> opened for that and trying to prevent people
> from mixing these problems together. :)

doh.  OK, thanks, that was the right thing to do ;)

Now we just need to find someone to fix the dang bugs.  We're
working on it.
Comment 11 Natalie Protasevich 2008-04-04 09:40:47 UTC
Stas, any luck with recent kernel? There were updates in this area since, can you re-test please.
Comment 12 Stas Sergeev 2008-04-04 10:56:41 UTC
Maybe there were some updates - last time
I tried, the printer used to jam all the
paper. Now it simply doesn't print at all,
which is better from some point of view.
pnpacpi=off still fixes it, so apparently
the problem is still there.
Could you please point to me to these updates
and maybe it will give me some clue about
the problem?
Comment 13 Natalie Protasevich 2008-04-04 12:07:23 UTC
It was massive update from Bjorn on PNPACPI a couple days ago. You should probably try the latest git. Copying to Bjorn...
Comment 14 Stas Sergeev 2008-04-04 12:36:51 UTC
Ah, it will unlikely to help then.
The pnpacpi is guilty here only by
enabling the DMA for parport_pc.
I suppose the DMA handling in parport_pc
is broken. Just disabling DMA by _some_
means (very difficult with the nonfunctional
module params) gets the printer back to work.
Comment 15 Stas Sergeev 2008-12-07 06:30:35 UTC
As per Bjorn's request.
I tested this on 2.6.27.
I also looked into Windows driver
resource usage, and it claims to
use DMA 3 and works fine in ECP mode.
I think Bug #5832 should be reopened
or marked as a duplicate of this one.
Comment 16 Bjorn Helgaas 2008-12-08 15:55:24 UTC
Thanks, Stas.  Did you happen to collect the pnp.debug log?

I doubt that you're seeing the same issue as Bug #5832, but it's certainly possible that another defect causes the same symptom.
Comment 17 Stas Sergeev 2008-12-10 01:48:28 UTC
Created attachment 19238 [details]
dmesg

Here's the dmesg with CONFIG_PNP_DEBUG.
pnp.debug option seem to be ignored though.
Comment 18 xerofoify 2014-06-24 16:54:49 UTC
This bug is against a obsolete kernel ,can you test with a stable kernel newer then 3.10. If it's fixed please close this bug , otherwise change to the kernel
version tested.
 Thanks Nick
Comment 19 Stas Sergeev 2014-06-25 06:43:49 UTC
Of course I can't do that 6 years later.
No such printer, no such motherboard.
Bug #5832 (which is a duplicate of this one)
have died for the same reason: nothing was fixed,
but the reporter no longer have the needed hardware.
Comment 20 Alan 2015-02-19 15:07:42 UTC
I think the reality is that par ports are now dying and this will never get fixed. So lets admit reality and close the bug

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