Re: 2.6.33 bugs (USBFS, Intel graphic)

[Greg KH]

On Sat, Feb 27, 2010 at 05:05:41AM +0100, Markus Rechberger wrote:
> On Sat, Feb 27, 2010 at 4:56 AM, Greg KH <greg@xxxxxxxxx> wrote:
> > On Sat, Feb 27, 2010 at 04:42:53AM +0100, Markus Rechberger wrote:
> >> * http://lkml.org/lkml/2010/2/19/192
> >> .6.32-stable review patch. ?If anyone has any objections, please let us know.
> >>
> >> ------------------
> >> From: Greg KH <greg@xxxxxxxxx>
> >>
> >> commit d4a4683ca054ed9917dfc9e3ff0f7ecf74ad90d6 upstream.
> >>
> >> We need to only copy the data received by the device to userspace, not
> >> the whole kernel buffer, which can contain "stale" data.
> >>
> >> Thanks to Marcus Meissner for pointing this out and testing the fix.
> >>
> >> Reported-by: Marcus Meissner <meissner@xxxxxxx>
> >> Tested-by: Marcus Meissner <meissner@xxxxxxx>
> >> Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> >> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> >> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
> >>
> >>
> >> this patch breaks isochronous USBFS support, please revert that patch!
> >>
> >> http://sundtek.de/images/tvtime-bildfehler.jpg
> >>
> >> with the patch reverted:
> >> http://sundtek.de/images/tvtime-working.png
> >>
> >> * Intel graphic flickers now
> >
> > That is very strange. ?What userspace program is using usbfs for video
> > feeds? ?And why would it be relying on the invalid data on the end of an
> > urb?
> >
> 
> there are 2 userspace videowrapper available for linux and freebsd
> which do videoprocessing in userland rather than in kernelspace.
> Well isochronous works slightly different than BULK transfer (which I
> guess was tested)
> urb->iso_frame_desc[i].actual_length
> each microframe has it's own length field for ISO.

Yes, and that patch didn't touch the iso frames.  That happens later on
in the functions that were modified.  The patch should not have had any
affect on iso transfers.  Unless I'm missing something?

confused,

greg k-h
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