Reference in a new issue

Blame

Copy permalink

Reference in a new issue

Copy permalink

Chris Wilson f22f4cf524 drm/i915: Limit the number of loops for reading a split 64bit register ... commit acd29f7b22 upstream. In I915_READ64_2x32 we attempt to read a 64bit register using 2 32bit reads. Due to the nature of the registers we try to read in this manner, they may increment between the two instruction (e.g. a timestamp counter). To keep the result accurate, we repeat the read if we detect an overflow (i.e. the upper value varies). However, some hardware is just plain flaky and may endless loop as the the upper 32bits are not stable. Just give up after a couple of tries and report whatever we read last. v2: Use the most recent values when erring out on an unstable register. Reported-by: russianneuromancer@ya.ru Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91906 Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Michał Winiarski <michal.winiarski@intel.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Jani Nikula <jani.nikula@linux.intel.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		History 2015-09-21 10:05:27 -07:00
..
drm	drm/i915: Limit the number of loops for reading a split 64bit register	2015-09-21 10:05:27 -07:00
host1x	gpu: host1x: Export host1x_syncpt_read()	2015-04-02 18:46:20 +02:00
ipu-v3	imx-drm changes to use media bus formats and LDB drm_panel support	2015-04-13 17:28:57 +10:00
vga	Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-10-13 16:23:15 +02:00
Makefile	gpu: host1x: Provide a proper struct bus_type	2015-01-27 10:09:14 +01:00