On Sun, Nov 1, 2009 at 6:15 PM, Andy Walls <awalls@xxxxxxxxx> wrote: > On Sun, 2009-11-01 at 17:59 -0500, Andy Walls wrote: >> On Sun, 2009-11-01 at 13:10 -0500, Brandon Jenkins wrote: >> > Hi Andy, >> > >> > The panic happens upon reboot and it is only 1 line of text oddly shifted. >> > >> > Kernel panic - not syncing: DMA: Memory would be corrupted >> > >> > If I switch back to the current v4l-dvb drivers no issue. To switch >> > back I have to boot from a USB drive. >> >> Brandon, >> >> Eww. OK. Nevermind performing any more data collection. I'm going to >> use a new strategy (when I find the time). > > I forgot to mention that the panic you are running into is in the > Software IO Memory Managment Unit Translate Look-aside Buffer (SW IOMMU > TLB) in > > linux/lib/swiotlb.c > > Your machine must not have a hardware IO MMU (and mine must). > > The software IOMMU is trying to allocate a bounce buffer for DMA and it > can't get one of the needed size (i.e. 607.5 kB) and the fallback static > buffer isn't big enough either (it is only 32 kB). That's why the panic > happens. > > This certainly means that, in the general linux user case, very large > DMA buffers are bad. > > So now I know.... > > > Regards, > Andy > > Hi Andy, How would I know if I have/don't have a HW IO MMU and maybe isn't enabled correctly? Separately, I also have three cards running too. Brandon -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
