Bug 9720

Summary:	DVB-USB UMT-010 driver has certain oops when installed
Product:	v4l-dvb	Reporter:	Austin Lund (austin.lund)
Component:	dvb-usb	Assignee:	dvb-usb (v4l-dvb_dvb-usb)
Status:	CLOSED PATCH_ALREADY_AVAILABLE
Severity:	normal	CC:	mchehab, protasnb
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	2.6.22	Subsystem:
Regression:	---	Bisected commit-id:

Description Austin Lund 2008-01-09 12:54:39 UTC

(Bug was first reported here: https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.22/+bug/115284)

In the umt-010 driver the struct umt_properties sets the number of URBs for transfer to 20.  But in dvb-usb.h MAX_NO_URBS_FOR_DATA_STREAM is set to 10.

Not surprisingly this causes an oops for all devices which use the umt-010 chipset when they are inserted.  

Either the .count variable must be decreased or the MAX_NO_URBS_FOR_DATA_STREAM must be increased.  When either is done the oops disappears. 

I don't have a functioning pll_desc for the tuner of my device, so I cannot test the actual results of this change.  But it does avoid a certain kernel oops.

Comment 1 Natalie Protasevich 2008-06-04 23:20:29 UTC

There is a fix by Tim Gardner in the launchpad entry:
http://kernel.ubuntu.com/git?p=ubuntu/ubuntu-hardy.git;a=blobdiff;f=drivers/media/dvb/dvb-usb/umt-010.c;h=4100d3319849c4297ad5288f2b5336ff0eb324a0;hp=0dcab3d4e2362bcfd5f1862a236aa56f4b94b920;hb=15826b4c16e487cedf83482aa46867d1ffb4d799;hpb=850c3d6fed840a941727645767e5cf0e70ef59c4

cc'ing to Mauro...

Comment 2 Austin Lund 2008-08-04 17:24:12 UTC

This fix seems to be in 2.6.26.  There have been many reports that it is fixed.