drm/fb: fix FBIOGET/PUT_VSCREENINFO pixel clock handling
authorClemens Ladisch <clemens@ladisch.de>
Wed, 4 Nov 2009 08:42:52 +0000 (09:42 +0100)
committerDave Airlie <airlied@redhat.com>
Tue, 24 Nov 2009 03:04:49 +0000 (13:04 +1000)
commit5349ef3127c77075ff70b2014f17ae0fbcaaf199
tree98d5c2234304833ba716c791aa7d5732a8d827cc
parent79cc304f3e2fda202242036326afb2aeca486156
drm/fb: fix FBIOGET/PUT_VSCREENINFO pixel clock handling

When the framebuffer driver does not publish detailed timing information
for the current video mode, the correct value for the pixclock field is
zero, not -1.

Since pixclock is actually unsigned, the value -1 would be interpreted
as 4294967295 picoseconds (i.e., about 4 milliseconds) by
register_framebuffer() and userspace programs.

This patch allows X.org's fbdev driver to work.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Tested-by: Paulius Zaleckas <paulius.zaleckas@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
drivers/gpu/drm/drm_fb_helper.c