Bug 194941

Summary:	dvb_usb_mxl111sf: transfer buffer not dma capable
Product:	Drivers	Reporter:	Dan Ziemba (zman0900)
Component:	Video(Other)	Assignee:	drivers_video-other
Status:	RESOLVED PATCH_ALREADY_AVAILABLE
Severity:	normal	CC:	barry
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	4.10.4	Subsystem:
Regression:	No	Bisected commit-id:
Attachments:	stack trace with 4.10.4

Description Dan Ziemba 2017-03-19 22:34:24 UTC

Created attachment 255353 [details]
stack trace with 4.10.4

After upgrading to kernel 4.9+, "Hauppauge WinTV-Aero-M" usb ATSC tuner card using the mxl111sf driver is no longer usable.  Dmesg shows error "transfer buffer not dma capable".  4.8.12 was the last kernel where this worked properly (I have not tried any later 4.8.x versions).  All versions of 4.9 and 4.10 that I have tested fail with the same error, including current 4.9.16 and 4.10.4. Stack trace from dmesg is attached.

This seems similar to the Fedora bug here, although this bug is about a dvb v1 driver and mxl111sf is dvb v2:
https://bugzilla.redhat.com/show_bug.cgi?id=1417829

Which seems to have been fixed by this change:
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=43fab9793c1f44e665b4f98035a14942edf03ddc

Comment 1 Dan Ziemba 2017-08-06 04:04:18 UTC

Driver is now working correctly with kernel 4.12.6 since this was added:
https://patchwork.kernel.org/patch/9693445/