[PATCH] v4l: oopsfix for BTTV on badly behaved PCI chipsets

no_overlay bttv parameter implemented to fix OOPS on some PCI chipsets
(like some VIA) with these behaviors:

1) If pci_quicks does identify the chip as having troubles to
   handle PCI2PCI transfers, no_overlay defaults to 1. The user may force
   it to 0, to reenable (not recommended).

2) For newer chipsets not blacklisted, no_overlay=1 is provided as a
   workaround until PCI chipset included on /drivers/pci/quirks.c

Thanks to Bodo Eggert <7eggert@gmx.de>

Signed-off-by: Michael Krufky <mkrufky@m1k.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@brturbo.com.br>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/Documentation/video4linux/bttv/Insmod-options b/Documentation/video4linux/bttv/Insmod-options
index 7bb5a50b077..fc94ff235ff 100644
--- a/Documentation/video4linux/bttv/Insmod-options
+++ b/Documentation/video4linux/bttv/Insmod-options
@@ -44,6 +44,9 @@ bttv.o
                                 push used by bttv.  bttv will disable overlay
                                 by default on this hardware to avoid crashes.
                                 With this insmod option you can override this.
+                no_overlay=1    Disable overlay. It should be used by broken
+                                hardware that doesn't support PCI2PCI direct
+                                transfers.
                 automute=0/1    Automatically mutes the sound if there is
                                 no TV signal, on by default.  You might try
                                 to disable this if you have bad input signal