From b6aa0873614dff74b01e18095fd335fbb1fb777c Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Wed, 2 Dec 2015 09:13:46 +0000 Subject: [PATCH] drm/i915: Fix RPS pointer passed from wait_ioctl to i915_wait_request In commit 2e1b873072dfe3bbcc158a9c21acde1ab0d36c55 [v4.2] Author: Chris Wilson 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 Cc: Daniel Vetter [danvet: Add Chris' explanation for why the impact of this is pretty close to 0.] Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_gem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 6356c347ede0..ef4dbe3d442d 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -3064,7 +3064,7 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file) 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; -- 2.11.0