[linux-dvb] Nova-T USB (908) ttusb_process_muxpack problems with 2.6.12.5 kernel...

Laz laz at club-burniston.co.uk
Wed Nov 16 19:57:32 CET 2005


I've just acquired a Nova-T USB model 908. I built the additional modules for 
it for my current kernel (2.6.12.5) on my vdr box, and the usb device is 
detected and hotplug loads the correct modules.

All looks great until I try to stream data from the card and watch it from 
vdr: it seems to be dropping almost alternate frames! dmesg gives me a 
continual stream of:

ttusb_process_muxpack: cc discontinuity (1 frames missing)
ttusb_process_muxpack: muxpack with incorrect checksum, ignoring
ttusb_process_muxpack: cc discontinuity (1 frames missing)
ttusb_process_muxpack: muxpack with incorrect checksum, ignoring
ttusb_process_muxpack: cc discontinuity (1 frames missing)
ttusb_process_muxpack: muxpack with incorrect checksum, ignoring
ttusb_process_frame: lost sync.
ttusb_process_muxpack: cc discontinuity (2 frames missing)
ttusb_process_muxpack: muxpack with incorrect checksum, ignoring
ttusb_process_muxpack: cc discontinuity (1 frames missing)
ttusb_process_muxpack: muxpack with incorrect checksum, ignoring
ttusb_process_frame: lost sync.

Which doesn't look particularly healthy!

This is on a Via Epia board with a PCI Nova-T as well, and using softdevice 
output with DirectFB.

In its wisdom, it has assigned the USB device, the framebuffer, and the 
on-board sound to the same IRQ:

           CPU0
  0:    1918588          XT-PIC  timer
  1:        553          XT-PIC  i8042
  2:          0          XT-PIC  cascade
  5:     936280          XT-PIC  viafb, uhci_hcd:usb2, uhci_hcd:usb4, VIA8233, 
eth0
  8:          4          XT-PIC  rtc
  9:     406150          XT-PIC  ehci_hcd:usb1, cx88[0], uhci_hcd:usb3, cx88
[0]
 12:        113          XT-PIC  i8042
 14:      38380          XT-PIC  ide0
NMI:          0
LOC:          0
ERR:          0
MIS:          0

Is this likely to be a problem down to not enough interrupts, or is this a 
driver problem? I do have a 2.6.14 kernel to test but I never managed to get 
the /dev/input/eventx to appear for the remote on the other DVB card with 
that kernel!

I did originally try two PCI DVB cards with an active riser (only one PCI 
slot) but that just couldn't cope!

Cheers,

Laz



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