drm/i915: Fix RPS pointer passed from wait_ioctl to i915_wait_request
In commit 2e1b873072dfe3bbcc158a9c21acde1ab0d36c55 [v4.2]
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date: Mon Apr 27 13:41:22 2015 +0100
drm/i915: Convert RPS tracking to a intel_rps_client struct
we converted the __i915_wait_request() to take a new intel_rps_client
struct (rather than having to pass fake drm_i915_file_private structs).
However, due to use of passing a void pointer, I didn't spot one
callsite in wait-ioctl was passing the wrong pointer.
Fwiw, the impact of this bug is zero. Along the rps path, we always
first call list_empty(rps) which when we pass in the wrong pointer
always evaluates to false and we return early and never chase the
invalid pointers.
The user visible impact is then wait-ioctl doesn't get the same
waitboosting as the other interfaces (set-domain, throttle), which is a
performance concern for the *very* few users of the wait interface.
There is also a libdrm_intel patch to use the wait-ioctl for
drm_intel_bo_wait_rendering() if anyone feels inclined to review
libdrm_intel patches.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
[danvet: Add Chris' explanation for why the impact of this is pretty
close to 0.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 6356c34..ef4dbe3 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3064,7 +3064,7 @@
if (ret == 0)
ret = __i915_wait_request(req[i], reset_counter, true,
args->timeout_ns > 0 ? &args->timeout_ns : NULL,
- file->driver_priv);
+ to_rps_client(file));
i915_gem_request_unreference__unlocked(req[i]);
}
return ret;