linux-kernel - [PATCH v7 6/8] drm/i915/display: Flush the front buffer in panic handler

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Message-ID: <20250425094949.473060-7-jfalempe@redhat.com>
Date: Fri, 25 Apr 2025 11:37:52 +0200
From: Jocelyn Falempe <jfalempe@...hat.com>
To: Jani Nikula <jani.nikula@...ux.intel.com>,
	Rodrigo Vivi <rodrigo.vivi@...el.com>,
	Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
	Tvrtko Ursulin <tursulin@...ulin.net>,
	Ville Syrjälä <ville.syrjala@...ux.intel.com>,
	David Airlie <airlied@...il.com>,
	Simona Vetter <simona@...ll.ch>,
	intel-gfx@...ts.freedesktop.org,
	intel-xe@...ts.freedesktop.org,
	dri-devel@...ts.freedesktop.org,
	linux-kernel@...r.kernel.org
Cc: Jocelyn Falempe <jfalempe@...hat.com>
Subject: [PATCH v7 6/8] drm/i915/display: Flush the front buffer in panic handler

On Lunar Lake, if the panic occurs when fbcon is active, the panic
screen is only partially visible on the screen. Adding this
intel_frontbuffer_flush() call solves the issue.
It's probably not safe to do that in the panic handler, but that's
still better than nothing.

Signed-off-by: Jocelyn Falempe <jfalempe@...hat.com>
---
 drivers/gpu/drm/i915/display/intel_atomic_plane.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_atomic_plane.c b/drivers/gpu/drm/i915/display/intel_atomic_plane.c
index c863249ab980..505719f53411 100644
--- a/drivers/gpu/drm/i915/display/intel_atomic_plane.c
+++ b/drivers/gpu/drm/i915/display/intel_atomic_plane.c
@@ -59,6 +59,7 @@
 #include "intel_fb.h"
 #include "intel_fb_pin.h"
 #include "intel_fbdev.h"
+#include "intel_frontbuffer.h"
 #include "skl_scaler.h"
 #include "skl_universal_plane.h"
 #include "skl_watermark.h"
@@ -1272,8 +1273,14 @@ static void intel_panic_flush(struct drm_plane *plane)
 	drm_clflush_virt_range(panic_map.vaddr, fb->height * fb->pitches[0]);
 
 	/* Don't disable tiling if it's the fbdev framebuffer.*/
-	if (to_intel_framebuffer(fb) == intel_fbdev_framebuffer(display->fbdev.fbdev))
+	if (to_intel_framebuffer(fb) == intel_fbdev_framebuffer(display->fbdev.fbdev)) {
+		struct intel_frontbuffer *front = to_intel_frontbuffer(fb);
+		struct drm_gem_object *obj = intel_fb_bo(fb);
+
+		intel_bo_flush_if_display(obj);
+		intel_frontbuffer_flush(front, ORIGIN_DIRTYFB);
 		return;
+	}
 
 	if (fb->modifier && iplane->disable_tiling)
 		iplane->disable_tiling(iplane);
-- 
2.49.0