> -----Original Message-----
> From: De Marchi, Lucas <lucas.demarchi@xxxxxxxxx>
> Sent: Tuesday, July 16, 2024 9:19 PM
> To: Shankar, Uma <uma.shankar@xxxxxxxxx>
> Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx; intel-xe@xxxxxxxxxxxxxxxxxxxxx;
> ville.syrjala@xxxxxxxxxxxxxxx; Ceraolo Spurio, Daniele
> <daniele.ceraolospurio@xxxxxxxxx>; Belgaumkar, Vinay
> <vinay.belgaumkar@xxxxxxxxx>; Roper, Matthew D
> <matthew.d.roper@xxxxxxxxx>
> Subject: Re: [v3] drm/xe/fbdev: Limit the usage of stolen for LNL+
>
> On Tue, Jul 16, 2024 at 12:30:43AM GMT, Uma Shankar wrote:
> >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.
>
> it's actually the same WA, just a different part of it
>
> a few nits below, otherwise this is
> // Reviewed-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
Thanks Lucas for the review. Will address the nits and float a next version.
Regards,
Uma Shankar
> > Used xe_root_mmio_gt and avoid the for loop.
> > (Suggested by Lucas)
> >
> >Signed-off-by: Uma Shankar <uma.shankar@xxxxxxxxx>
> >---
> > 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;
>
> no need for the bool, just use XE_WA() in the one place needed.
>
> >
> > /* 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)
>
> better to put the line here as it's actually the same WA, just a different part of it.
> It's easier if we group them close together.
>
> Daniele, can you check the gsc patch now works with this addition to the WA?
>
> thanks
> Lucas De Marchi
>
> > 16023588340 GRAPHICS_VERSION(2001)
> >+22019338487_display PLATFORM(LUNARLAKE)
> >--
> >2.42.0
> >
