3e8f3d6fa6
Add support for fbdev mmap clients who don't send damage ioctls Because DisplayLink devices are out on the other end of usb, their "framebuffer" is just normal system memory. So memory mapped writes don't automatically trigger anything. So up to this point, standard fbdev clients who rely on mmap() will get an unchanging screen. This patch makes udlfb a client of Jaya Kumar's defio framework - which sets up page fault triggers, and those faults are accumulated and sent to udlfb on a defferred basis, to process as damage notifications for the framebuffer. Because this involves more overhead than a notification directly from the application (e.g. just passing on X DAMAGE extension notifications), a sysfs attribute is provided by udlfb to control defio support. /sys/class/graphics/fb*/use_defio - writing a "0" to this file before calling mmap() causes defio to not be initialized - instead udlfb will rely on getting damage notifications directly through the damage ioctl. There are unsolved rendering problems with defio (horizontal dead regions on framebuffer, that accumulate over time) which still needs a fix. Signed-off-by: Bernie Thompson <bernie@plugable.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
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| Kconfig | ||
| Makefile | ||
| udlfb.c | ||
| udlfb.h | ||