drm/i915/ttm: Abort suspend on i915_ttm_backup failure

On system suspend when system memory is low then i915_gem_obj_copy_ttm()
could fail trying to backup a lmem obj. GEM_WARN_ON() is not enough,
suspend shouldn't continue if i915_ttm_backup() throws an error.

v2: Keep the fdo issue till we have a igt test(Matt).
v3: Use %pe(Andrzej)

References: https://gitlab.freedesktop.org/drm/intel/-/issues/6529
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Suggested-by: Chris P Wilson <chris.p.wilson@intel.com>
Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220901172217.18392-1-nirmoy.das@intel.com

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm_pm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm_pm.c
index 9aad840..07e49f2 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm_pm.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm_pm.c
@@ -79,7 +79,12 @@ static int i915_ttm_backup(struct i915_gem_apply_to_region *apply,
                goto out_no_populate;
 
        err = i915_gem_obj_copy_ttm(backup, obj, pm_apply->allow_gpu, false);
-       GEM_WARN_ON(err);
+       if (err) {
+               drm_err(&i915->drm,
+                       "Unable to copy from device to system memory, err:%pe\n",
+                       ERR_PTR(err));
+               goto out_no_populate;
+       }
        ttm_bo_wait_ctx(backup_bo, &ctx);
 
        obj->ttm.backup = backup;