Details
-
Bug
-
Resolution: Invalid
-
Not Evaluated
-
None
-
4.8.7
-
None
-
X.Org X Server 1.18.0
Release Date: 2015-11-09
X Protocol Version 11, Revision 0
Build Operating System: Linux 4.2.3-1-ARCH x86_64
Kernel command line: \vmlinuz-linux ro root=UUID=1b512de4-696f-42b1-924e-55f1aadfa049 quiet nmi_watchdog=0 i915.enable_fbc=1 i915.enable_rc6=1 i915.lvds_downclock=1 i915.semaphores=1 initrd=intel-ucode.img initrd=initramfs-linux.img
X.Org X Server 1.18.0 Release Date: 2015-11-09 X Protocol Version 11, Revision 0 Build Operating System: Linux 4.2.3-1-ARCH x86_64 Kernel command line: \vmlinuz-linux ro root=UUID=1b512de4-696f-42b1-924e-55f1aadfa049 quiet nmi_watchdog=0 i915.enable_fbc=1 i915.enable_rc6=1 i915.lvds_downclock=1 i915.semaphores=1 initrd=intel-ucode.img initrd=initramfs-linux.img
Description
I turned on the fbc (framebuffer compression) flag for i915, and qt stopped responding to keyboard events.
E.G typing in lyx [a qt front-ended LaTeX editor] would not update the application, so the words you were typing would be unchanged until 5-10 seconds passed, or you moved the mouse. I have no idea why this behavior happened, but it doesn't seem to occur in applications based in other frameworks [gtk based, for example]
I tested this in several qt4 applications, and it seemed to be a problem in all of them.
It would be nice if you could find the problem, as FBC adds quite a bit of battery life to laptops running intel integrated graphics, but I understand if this is an upstream or compatibility bug somewhere.