Testers wanted (was: Re: [linux-dvb] PATCH for SAA7146 DMA buffer overflow in budget cards (updated))

Oliver Endriss o.endriss at gmx.de
Sat Mar 18 20:39:25 CET 2006

Oliver Endriss wrote:
> Ingo Schneider wrote:
> > Hello again !
> > 
> > Here comes a Patch which does the following changes for all ttpci budget 
> > cards:
> > - Issue a warning when more than 80% of the DMA buffer is being used 
> > (probably due to bad IRQ latency)
> >  Warnings are limited to the first 100 warnings and after that one 
> > warning for every 100 buffer overruns.
> > - Introduce a new parameter "bufsize" (in k) which increases the default 
> > DMA buffer of 188k up to 4 MB
> >  A buffer size of 470k does it for me even at high I/O load conditions.
> > - Now the patch doesn't break budget-patch anymore
> > 
> > Signed-off-by: Ingo Schneider <mail at ingo-schneider.de>
> > 
> > Oliver, can you please integrate this patch ?
> Sorry for the delay.
> This weekend I will do some tests with different buffer settings.
> Unfortunately, I can only test Activy GR and old-style Nova hardware
> (budget driver).
> I'd appreciate if more people would test the patch with different
> hardware (budget-ci, budget-av, budget-patch driver).
> Please report _any_ problems. Thanks.
> Anyway, I still don't like the way buffer warnings are logged.
> syslog might be flooded with 100 buffer warnings in worst case.
> I will make error logging rate-limited, i.e. no more than one message
> every 30 seconds will be logged. The error counter will be cleared after
> logging the message. That should be sufficient to detect any problems.

Ok, my proposal based on Ingo's patch:
- simplified calculation of dma buffer size:
  never change buffer_width, buffer size limited to 1410K (Activy 564K)
- not more than one buffer warning every 30 seconds
- removed unused struct member 'tsf'
- whitespace clean-up

All buffer sizes have been tested with Nova-S and Activy GR.

If this patch is ok for you I will commit it.


Could someone please test the budget-patch driver with this patch?

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