Em Tue, 14 Feb 2017 11:41:46 -0800 Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> escreveu: > On Tue, Feb 14, 2017 at 05:32:11PM -0200, Mauro Carvalho Chehab wrote: > > Reported as a Kaffeine bug: > > https://bugs.kde.org/show_bug.cgi?id=375811 > > > > The USB control messages require DMA to work. We cannot pass > > a stack-allocated buffer, as it is not warranted that the > > stack would be into a DMA enabled area. > > > > On Kernel 4.9, the default is to not accept DMA on stack anymore. > > > > Tested with USB ID 2040:5510: Hauppauge Windham > > > > Cc: stable@xxxxxxxxxxxxxxx # For 4.9+ > > Unless there is some major reason, this should go into _all_ stable > releases, as the driver would be broken on them all for platforms that > can't handle USB data that is not DMA-able. This has been a requirement > for USB drivers since the 2.2 days. Good point! No, there's no particular reason why not backporting it to older Kernel releases. I suspect that this particular part of the driver hasn't changed for a while. So, it can very likely be backported to all stable releases. I'll fix the C/C message when submitting it upstream. Thanks, Mauro
