[Intel-gfx] [PATCH] drm/i915: Report to userspace if we have a (presumed) working GPU reset

[Chris Wilson]

On Mon, Jun 15, 2015 at 03:45:38PM +0200, Daniel Vetter wrote:
> On Mon, Jun 15, 2015 at 12:23:48PM +0100, Chris Wilson wrote:
> > In igt, we want to test handling of GPU hangs, both for recovery
> > purposes and for reporting. However, we don't want to inject a genuine
> > GPU hang onto a machine that cannot recover and so be permenantly
> > wedged. Rather than embed heuristics into igt, have the kernel report
> > exactly when it expects the GPU reset to work.
> > 
> > This can also be usefully extended in future to indicate different
> > levels of fine-grained resets.
> > 
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> > Cc: Tim Gore <tim.gore at intel.com>
> > Cc: Tomas Elf <tomas.elf at intel.com>
> 
> Yeah makes sense. Will merge as soon as someone smashes a t-b with a few
> igt patches using this on top.

diff --git a/lib/igt_gt.c b/lib/igt_gt.c
index deb5560..8a1ffb2 100644
--- a/lib/igt_gt.c
+++ b/lib/igt_gt.c
@@ -26,6 +26,7 @@
 #include <errno.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/ioctl.h>
 #include <fcntl.h>
 
 #include "drmtest.h"
@@ -47,6 +48,21 @@
  * engines.
  */
 
+static bool has_gpu_reset(int fd)
+{
+       struct drm_i915_getparam gp;
+       int val = 0;
+
+       memset(&gp, 0, sizeof(gp));
+       gp.param = 35; /* HAS_GPU_RESET */
+       gp.value = &val;
+
+       if (ioctl(fd, DRM_IOCTL_I915_GETPARAM, &gp, sizeof(gp)))
+               return intel_gen(intel_get_drm_devid(fd)) >= 5;
+
+       return val > 0;
+}
 
 /**
  * igt_require_hang_ring:
@@ -60,7 +76,7 @@
 void igt_require_hang_ring(int fd, int ring)
 {
        gem_context_require_ban_period(fd);
-       igt_require(intel_gen(intel_get_drm_devid(fd)) >= 5);
+       igt_require(has_gpu_reset(fd));
 }
 
 /**


-- 
Chris Wilson, Intel Open Source Technology Centre