> I think it is becoming very clear that the choice of PCI burst used by the > budget driver is inappropriate for many chipsets, including common stuff > like the i845, many via boards, and also the i865 (my Asus P4P800)
Yes, I can confirm this. Maybe we should gather some recommended values and list them somewhere. > That snippet you refer to gives advised values for a series of boards. > However, in my case (asus P4P800) I had to go to zero to get any kind of > stable transfer (I didn't try 2 & 4 DWords, but 16 and 32 were still > unstable). I assume that this is equivalent to switching off PCI bursting > altogether? Without a value of in PCI_BT_V1 I was seeing very severe > corruption of the mpeg stream (mplayer typically dies within 1-2 seconds) I have used vdr the last months with this "anomaly", it didn't die, but it had a choppy live stream. Tonight I have tried various combinations of threshold and burst rates, and I get an almost perfect results with a 8 Dwords burst and a 4 Dwords threshold (i845 machine). The most sensitive parameter is the threshold value, which unfortunately can only be lowered to 4 Dwords. > I would be happy to make the value a kernel module option? Would this be > accepted as a patch? If so, would it need to be done against both the DVB > and dvb_kernel branches? Also, what would be the implications of changing > the default to 0? Is this going to be loading the PCI bus unneccessarily > for other users? I had the same idea, recompiling the kernel took too long. It is a very small patch, I have posted it to the list in a new thread. Changing the value to 0 made my situation worse. I suppose there will be no one-value-fits-all solution. > Your other question, does the budget card use only DMA channel 3? Yes I > think it does based on some other posting in that thread. Certainly in my > case it was only altering that which caused/fixed problems. I think the > full featured cards make use of the other registers, but because the > output > is buffered by the AV7110 (is that right?) the timing is far less > important I have taken a closer look into budget-core.c, it seems that only DMA 3 is used for budget cards. > > So - Should I submit a patch? What would the preferred default be? > > Ed W -- Info: To unsubscribe send a mail to [EMAIL PROTECTED] with "unsubscribe linux-dvb" as subject.
