linux-kernel - [PATCH v4 6/8] drm/i915/display: Flush the front buffer in panic handler

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Message-ID: <20250213112620.1923927-7-jfalempe@redhat.com>
Date: Thu, 13 Feb 2025 12:19:30 +0100
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>,
	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 v4 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 96697ac0ef69a..ee8cc82af3a8b 100644
--- a/drivers/gpu/drm/i915/display/intel_atomic_plane.c
+++ b/drivers/gpu/drm/i915/display/intel_atomic_plane.c
@@ -56,6 +56,7 @@
 #include "intel_fb.h"
 #include "intel_fb_pin.h"
 #include "intel_fbdev.h"
+#include "intel_frontbuffer.h"
 #include "skl_scaler.h"
 #include "skl_watermark.h"
 
@@ -1211,8 +1212,14 @@ 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(dev_priv->display.fbdev.fbdev))
+	if (to_intel_framebuffer(fb) == intel_fbdev_framebuffer(dev_priv->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);
-- 
2.47.1