From 4cfe4c0efbdcde742a47813180cc69b132d7598e Mon Sep 17 00:00:00 2001 From: Sebastian Brzezinka Date: Thu, 16 Apr 2026 13:31:18 +0200 Subject: [PATCH 1/2] drm/i915: skip __i915_request_skip() for already signaled requests After a GPU reset the HWSP is zeroed, so previously completed requests appear incomplete. If such a request is picked up during reset_rewind() and marked guilty, i915_request_set_error_once() returns early (fence already signaled), leaving fence.error without a fatal error code. The subsequent __i915_request_skip() then hits: ``` GEM_BUG_ON(!fatal_error(rq->fence.error)) ``` Fixes a kernel BUG observed on Sandy Bridge (Gen6) during heartbeat-triggered engine resets. ``` kernel BUG at drivers/gpu/drm/i915/i915_request.c:556! RIP: __i915_request_skip+0x15e/0x1d0 [i915] ... __i915_request_reset+0x212/0xa70 [i915] reset_rewind+0xe4/0x280 [i915] intel_gt_reset+0x30d/0x5b0 [i915] heartbeat+0x516/0x530 [i915] ``` Guard __i915_request_skip() with i915_request_signaled(), if the fence is already signaled, the ring content is committed and there is nothing left to skip. Fixes: 36e191f0644b ("drm/i915: Apply i915_request_skip() on submission") Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/work_items/13729 Signed-off-by: Sebastian Brzezinka Cc: stable@vger.kernel.org # v5.7+ Reviewed-by: Krzysztof Karas Reviewed-by: Andi Shyti Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/fe76921d35b6ae85aa651822726d0d9815aa5362.1776339012.git.sebastian.brzezinka@intel.com (cherry picked from commit 5ba54393dcd7adf75a9f39f5a933b1538349cad5) Signed-off-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/gt/intel_reset.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/gt/intel_reset.c b/drivers/gpu/drm/i915/gt/intel_reset.c index 984d0056c01c..adff482a6c9c 100644 --- a/drivers/gpu/drm/i915/gt/intel_reset.c +++ b/drivers/gpu/drm/i915/gt/intel_reset.c @@ -132,7 +132,8 @@ void __i915_request_reset(struct i915_request *rq, bool guilty) rcu_read_lock(); /* protect the GEM context */ if (guilty) { i915_request_set_error_once(rq, -EIO); - __i915_request_skip(rq); + if (!i915_request_signaled(rq)) + __i915_request_skip(rq); banned = mark_guilty(rq); } else { i915_request_set_error_once(rq, -EAGAIN); From 1ae15b6c7965d137eef21f2cc7d367b29cb88369 Mon Sep 17 00:00:00 2001 From: Chaitanya Kumar Borah Date: Tue, 5 May 2026 14:39:20 +0530 Subject: [PATCH 2/2] drm/i915/dp: Fix VSC dynamic range signaling for RGB formats For RGB, set dynamic_range to CTA or VESA based on crtc_state->limited_color_range so sinks apply correct quantization. YCbCr remains limited (CTA) range. (DP v1.4, Table 5-1) v2: - Added Reported-by and Tested-by tags v3: - Add back YCbCr comment(Suraj) Cc: stable@vger.kernel.org #v5.8+ Reported-by: DeepChirp Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/work_items/15874 Tested-by: DeepChirp Fixes: 9799c4c3b76e ("drm/i915/dp: Add compute routine for DP VSC SDP") Assisted-by: GitHub-Copilot:GPT-5.4 Signed-off-by: Chaitanya Kumar Borah Reviewed-by: Suraj Kandpal Signed-off-by: Suraj Kandpal Link: https://patch.msgid.link/20260505090920.2479112-1-chaitanya.kumar.borah@intel.com (cherry picked from commit 38e10ddae6f8d42a2e8437fcd25a1cac51106c64) Signed-off-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/display/intel_dp.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 4955bd8b11d7..50d34b4fdf82 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -3119,8 +3119,13 @@ static void intel_dp_compute_vsc_colorimetry(const struct intel_crtc_state *crtc drm_WARN_ON(display->drm, vsc->bpc == 6 && vsc->pixelformat != DP_PIXELFORMAT_RGB); - /* all YCbCr are always limited range */ - vsc->dynamic_range = DP_DYNAMIC_RANGE_CTA; + /* All YCbCr formats are always limited range. */ + if (vsc->pixelformat == DP_PIXELFORMAT_RGB) + vsc->dynamic_range = crtc_state->limited_color_range ? + DP_DYNAMIC_RANGE_CTA : DP_DYNAMIC_RANGE_VESA; + else + vsc->dynamic_range = DP_DYNAMIC_RANGE_CTA; + vsc->content_type = DP_CONTENT_TYPE_NOT_DEFINED; }