[v3] drm/xe/fbdev: Limit the usage of stolen for LNL+

Uma Shankar uma.shankar at intel.com
Mon Jul 15 19:00:43 UTC 2024


As per recommendation in the workarounds:
WA_22019338487

There is an issue with accessing Stolen memory pages due a
hardware limitation. Limit the usage of stolen memory for
fbdev for LNL+. Don't use BIOS FB from stolen on LNL+ and
assign the same from system memory.

v2: Corrected the WA Number, limited WA to LNL and
    Adopted XE_WA framework as suggested by Lucas and Matt.

v3: Introduced the waxxx_display to avoid tipping on other WA.
    Used xe_root_mmio_gt and avoid the for loop.
    (Suggested by Lucas)

Signed-off-by: Uma Shankar <uma.shankar at intel.com>
---
 drivers/gpu/drm/xe/display/intel_fbdev_fb.c   | 10 +++++++++-
 drivers/gpu/drm/xe/display/xe_plane_initial.c |  6 ++++++
 drivers/gpu/drm/xe/xe_wa_oob.rules            |  1 +
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/xe/display/intel_fbdev_fb.c b/drivers/gpu/drm/xe/display/intel_fbdev_fb.c
index 816ad13821a8..0f02e6222ada 100644
--- a/drivers/gpu/drm/xe/display/intel_fbdev_fb.c
+++ b/drivers/gpu/drm/xe/display/intel_fbdev_fb.c
@@ -10,6 +10,9 @@
 #include "xe_bo.h"
 #include "xe_gt.h"
 #include "xe_ttm_stolen_mgr.h"
+#include "xe_wa.h"
+
+#include <generated/xe_wa_oob.h>
 
 struct intel_framebuffer *intel_fbdev_fb_alloc(struct drm_fb_helper *helper,
 					       struct drm_fb_helper_surface_size *sizes)
@@ -20,6 +23,7 @@ struct intel_framebuffer *intel_fbdev_fb_alloc(struct drm_fb_helper *helper,
 	struct drm_mode_fb_cmd2 mode_cmd = {};
 	struct drm_i915_gem_object *obj;
 	int size;
+	bool wa_22019338487 = false;
 
 	/* we don't do packed 24bpp */
 	if (sizes->surface_bpp == 24)
@@ -37,7 +41,10 @@ struct intel_framebuffer *intel_fbdev_fb_alloc(struct drm_fb_helper *helper,
 	size = PAGE_ALIGN(size);
 	obj = ERR_PTR(-ENODEV);
 
-	if (!IS_DGFX(xe)) {
+	if (XE_WA(xe_root_mmio_gt(xe), 22019338487_display))
+		wa_22019338487 = true;
+
+	if (!IS_DGFX(xe) && !wa_22019338487) {
 		obj = xe_bo_create_pin_map(xe, xe_device_get_root_tile(xe),
 					   NULL, size,
 					   ttm_bo_type_kernel, XE_BO_FLAG_SCANOUT |
@@ -48,6 +55,7 @@ struct intel_framebuffer *intel_fbdev_fb_alloc(struct drm_fb_helper *helper,
 		else
 			drm_info(&xe->drm, "Allocated fbdev into stolen failed: %li\n", PTR_ERR(obj));
 	}
+
 	if (IS_ERR(obj)) {
 		obj = xe_bo_create_pin_map(xe, xe_device_get_root_tile(xe), NULL, size,
 					   ttm_bo_type_kernel, XE_BO_FLAG_SCANOUT |
diff --git a/drivers/gpu/drm/xe/display/xe_plane_initial.c b/drivers/gpu/drm/xe/display/xe_plane_initial.c
index 5eccd6abb3ef..a50ab9eae40a 100644
--- a/drivers/gpu/drm/xe/display/xe_plane_initial.c
+++ b/drivers/gpu/drm/xe/display/xe_plane_initial.c
@@ -18,6 +18,9 @@
 #include "intel_frontbuffer.h"
 #include "intel_plane_initial.h"
 #include "xe_bo.h"
+#include "xe_wa.h"
+
+#include <generated/xe_wa_oob.h>
 
 static bool
 intel_reuse_initial_plane_obj(struct intel_crtc *this,
@@ -104,6 +107,9 @@ initial_plane_bo(struct xe_device *xe,
 		phys_base = base;
 		flags |= XE_BO_FLAG_STOLEN;
 
+		if (XE_WA(xe_root_mmio_gt(xe), 22019338487_display))
+			return NULL;
+
 		/*
 		 * If the FB is too big, just don't use it since fbdev is not very
 		 * important and we should probably use that space with FBC or other
diff --git a/drivers/gpu/drm/xe/xe_wa_oob.rules b/drivers/gpu/drm/xe/xe_wa_oob.rules
index 08f7336881e3..6ec23c4b972e 100644
--- a/drivers/gpu/drm/xe/xe_wa_oob.rules
+++ b/drivers/gpu/drm/xe/xe_wa_oob.rules
@@ -30,3 +30,4 @@
 22019338487	MEDIA_VERSION(2000)
 		GRAPHICS_VERSION(2001)
 16023588340	GRAPHICS_VERSION(2001)
+22019338487_display	PLATFORM(LUNARLAKE)
-- 
2.42.0



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