mirror of https://gitee.com/openkylin/linux.git
a55944ca82
We don't have to update the state and fb_blank properties of a backlight device every time a blanking or unblanking event comes because they may have already been what we want. Another thought is that one backlight device may be shared by multiple framebuffers. The backlight driver should take the backlight device as a resource shared by all the associated framebuffers. This patch adds some logic to record each framebuffer's backlight usage to determine the backlight device use count and whether the two properties should be updated or not. To be more specific, only one unblank operation on a certain blanked framebuffer may increase the backlight device's use count by one, while one blank operation on a certain unblanked framebuffer may decrease the use count by one, because the userspace is likely to unblank an unblanked framebuffer or blank a blanked framebuffer. Signed-off-by: Liu Ying <Ying.Liu@freescale.com> Cc: Jingoo Han <jg1.han@samsung.com> Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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| linux | ||
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