Disable acceleration if we detect a hardware error.

This is wildly optimistic, but it should work in a surprising number of
error situations and some output in those cases will be hopefully be
better than none...

If we submit a batchbuffer and the kernel reports the GPU is hung (which
will be caused by an earlier execbuffer, and so the kernel should have
had enough time to determine whether or not it could reset the GPU) then
disable any further attempt to accelerate gfx and force fallbacks to map
the buffers and use the CPU. We cannot normally map any more buffers if
the GPU is hung, so only those already mapped prior to the hang can be
written to, or those allocated in system memory. However, we can expect
that the framebuffer is already mapped, and so have a reasonable
expectation to continue to see the display update.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 9 insertions, 0 deletions

diff --git a/uxa/uxa.c b/uxa/uxa.c
index 330b3893..a9a705c2 100644
--- a/uxa/uxa.c
+++ b/uxa/uxa.c
@@ -350,6 +350,13 @@ void uxa_set_fallback_debug(ScreenPtr screen, Bool enable)
 	uxa_screen->fallback_debug = enable;
 }
 
+void uxa_set_force_fallback(ScreenPtr screen, Bool value)
+{
+	uxa_screen_t *uxa_screen = uxa_get_screen(screen);
+
+	uxa_screen->force_fallback = value;
+}
+
 /**
  * uxa_close_screen() unwraps its wrapped screen functions and tears down UXA's
  * screen private, before calling down to the next CloseSccreen.
@@ -473,6 +480,8 @@ Bool uxa_driver_init(ScreenPtr screen, uxa_driver_t * uxa_driver)
 
 	dixSetPrivate(&screen->devPrivates, &uxa_screen_index, uxa_screen);
 
+	uxa_screen->force_fallback = FALSE;
+
 	uxa_screen->solid_cache_size = 0;
 	uxa_screen->solid_clear = 0;
 	uxa_screen->solid_black = 0;