[linux-dvb] Re: FIX: av7110 driver unusable after 'dvb-ttpci: warning: timeout waiting in BlitBitmap()'

[Johannes Stezenbach <js@linuxtv.org>]

Oliver Endriss wrote:
> Johannes Stezenbach wrote:
> > Oliver Endriss wrote:
> > > FYI, another bug has been fixed:
> > > Under heavy load the bitmap transfer could be aborted by the driver due
> > > to a timeout. In this case the ARM would not process OSD commands
> > > anymore, and the driver must be reloaded.
> > 
> > Nice, but it is more a workaround than a bugfix.
> > And a ten second timeout is a bit longish, don't you think?
> > Anyway, the question is why the timeout happens. I'm still
> > trying to figure that out.
> 
> Well, the problem is that the bandwidth for DPRAM data transfers is
> limited. If you start enough simultaneous recordings with vdr, OSD
> requests cannot be serviced anymore.
> 
> On the other hand, if you increase the priority of the bitmap transfers,
> you would probably damage your recordings. :-(
> 
> Previously, the driver aborted the transfer after 1 second.
> In this state the firmware waited for the next buffer. Forever.
> (The old drivers would block forever. This is bad, since the transfer
> might never complete due to heavy load.)
> 
> Now there is a timeout in the 261d firmware and a longer timeout in the
> driver. Under heavy load, the request will time-out on both sides, but
> the system will never run into a deadlock.
> 
> Now I can do up to 4 recordings on a FF card and still use the OSD.
> It's somewhat slow but it works.

Ah, OK, I thought you are seeing spurious OSD timeouts. which
is what I get when I playback one recording in fast-forward
with the OSD progress bar open after about one minute.
But my problem could be due to the changes I made to add SMP
support (for the benifit of hype-threading ;-) to the av7110 driver.

Johannes