We don't have to turn backlight on/off every time a blanking or unblanking event comes because the backlight status may have already been what we want. Another thought is that one backlight device may be shared by multiple framebuffers. We don't hope blanking one of the framebuffers may turn the backlight off for all the other framebuffers, since they are likely being active to display something. This patch set adds some logics to record each framebuffer's backlight usage to determine the backlight device use count and whether the backlight status should be updated or not. Liu Ying (2): backlight: update bd state & fb_blank properties when necessary backlight: update backlight status when necessary v3->v4: * Split v3 into 2 patches to separate the change for updating the backlight device properties and backlight status, according to the comments from Jani Nikula and Jingoo Han. v2->v3: * Set fb_blank(*(int *)evdata->data) to bd->props.fb_blank when we turn off a blacklight. * Correct some trivial typos in the commit message. v1->v2: * Make the commit message be more specific about the condition in which backlight device use count can be increased/decreased. * Correct the setting for bd->props.fb_blank. drivers/video/backlight/backlight.c | 28 +++++++++++++++++++++------- include/linux/backlight.h | 6 ++++++ 2 files changed, 27 insertions(+), 7 deletions(-) -- 1.7.9.5 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel