[PATCH v8 8/8] drm/ast: Add drm_panic support

[Jocelyn Falempe]

Add support for the drm_panic module, which displays a message to
the screen when a kernel panic occurs.

v7
 * Use drm_for_each_primary_visible_plane()

v8:
 * Replace get_scanout_buffer() logic with drm_panic_set_buffer()
   (Thomas Zimmermann)

Signed-off-by: Jocelyn Falempe <jfale...@redhat.com>
---
 drivers/gpu/drm/ast/ast_mode.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c
index a718646a66b8..3d6d4c71bc34 100644
--- a/drivers/gpu/drm/ast/ast_mode.c
+++ b/drivers/gpu/drm/ast/ast_mode.c
@@ -43,6 +43,7 @@
 #include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/drm_gem_shmem_helper.h>
 #include <drm/drm_managed.h>
+#include <drm/drm_panic.h>
 #include <drm/drm_probe_helper.h>
 #include <drm/drm_simple_kms_helper.h>
 
@@ -656,9 +657,13 @@ static void ast_primary_plane_helper_atomic_update(struct 
drm_plane *plane,
                struct drm_crtc_state *crtc_state = 
drm_atomic_get_new_crtc_state(state, crtc);
                struct ast_crtc_state *ast_crtc_state = 
to_ast_crtc_state(crtc_state);
                struct ast_vbios_mode_info *vbios_mode_info = 
&ast_crtc_state->vbios_mode_info;
+               struct iosys_map map;
 
                ast_set_color_reg(ast, fb->format);
                ast_set_vbios_color_reg(ast, fb->format, vbios_mode_info);
+
+               iosys_map_set_vaddr_iomem(&map, ast_plane->vaddr);
+               drm_panic_set_buffer(plane->panic_scanout, fb, &map);
        }
 
        drm_atomic_helper_damage_iter_init(&iter, old_plane_state, plane_state);
@@ -736,6 +741,7 @@ static int ast_primary_plane_init(struct ast_device *ast)
        }
        drm_plane_helper_add(primary_plane, &ast_primary_plane_helper_funcs);
        drm_plane_enable_fb_damage_clips(primary_plane);
+       drm_panic_register(primary_plane);
 
        return 0;
 }
-- 
2.43.0