[PATCH] drm/xe/dp: Enable DP tunneling

[Lucas De Marchi]

On Mon, Jan 13, 2025 at 05:48:32PM +0200, Imre Deak wrote:
>Enable the DP tunneling functionality in the xe driver.
>
>Signed-off-by: Imre Deak <imre.deak at intel.com>
>---
> drivers/gpu/drm/i915/display/intel_dp_tunnel.h |  5 +++--
> drivers/gpu/drm/xe/Kconfig                     | 14 ++++++++++++++
> drivers/gpu/drm/xe/Makefile                    |  3 +++
> 3 files changed, 20 insertions(+), 2 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/display/intel_dp_tunnel.h b/drivers/gpu/drm/i915/display/intel_dp_tunnel.h
>index e9314cf25a193..7a91b4945eb8d 100644
>--- a/drivers/gpu/drm/i915/display/intel_dp_tunnel.h
>+++ b/drivers/gpu/drm/i915/display/intel_dp_tunnel.h
>@@ -20,7 +20,8 @@ struct intel_dp;
> struct intel_encoder;
> struct intel_link_bw_limits;
>
>-#if IS_ENABLED(CONFIG_DRM_I915_DP_TUNNEL) && defined(I915)
>+#if (defined(CONFIG_DRM_I915_DP_TUNNEL) && defined(I915)) || \
>+	(defined(CONFIG_DRM_XE_DP_TUNNEL) && !defined(I915))
>
> int intel_dp_tunnel_detect(struct intel_dp *intel_dp, struct drm_modeset_acquire_ctx *ctx);
> void intel_dp_tunnel_disconnect(struct intel_dp *intel_dp);
>@@ -127,6 +128,6 @@ intel_dp_tunnel_mgr_init(struct intel_display *display)
>
> static inline void intel_dp_tunnel_mgr_cleanup(struct intel_display *display) {}
>
>-#endif /* CONFIG_DRM_I915_DP_TUNNEL */
>+#endif /* CONFIG_DRM_I915_DP_TUNNEL || CONFIG_DRM_XE_DP_TUNNEL */
>
> #endif /* __INTEL_DP_TUNNEL_H__ */
>diff --git a/drivers/gpu/drm/xe/Kconfig b/drivers/gpu/drm/xe/Kconfig
>index b51a2bde73e29..50cf80df51900 100644
>--- a/drivers/gpu/drm/xe/Kconfig
>+++ b/drivers/gpu/drm/xe/Kconfig
>@@ -59,6 +59,20 @@ config DRM_XE_DISPLAY
> 	help
> 	  Disable this option only if you want to compile out display support.
>
>+config DRM_XE_DP_TUNNEL
>+	bool "Enable DP tunnel support"
>+	depends on DRM_XE
>+	depends on USB4
>+	select DRM_DISPLAY_DP_TUNNEL
>+	default y
>+	help
>+	  Choose this option to detect DP tunnels and enable the Bandwidth
>+	  Allocation mode for such tunnels. This allows using the maximum
>+	  resolution allowed by the link BW on all displays sharing the
>+	  link BW, for instance on a Thunderbolt link.
>+
>+	  If in doubt say "Y".
>+
> config DRM_XE_FORCE_PROBE
> 	string "Force probe xe for selected Intel hardware IDs"
> 	depends on DRM_XE
>diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
>index 5c97ad6ed7385..81f63258a7e19 100644
>--- a/drivers/gpu/drm/xe/Makefile
>+++ b/drivers/gpu/drm/xe/Makefile
>@@ -301,6 +301,9 @@ ifeq ($(CONFIG_DEBUG_FS),y)
> 		i915-display/intel_pipe_crc.o
> endif
>
>+xe-$(CONFIG_DRM_XE_DP_TUNNEL) += \
>+	i915-display/intel_dp_tunnel.o

something looks wrong here. We shouldn't build anything in i915-display/ if
we don't have DRM_XE_DISPLAY. Are you missing a

	depends on XE_DISPLAY
?

and in fact, with the .config I get:

In file included from ../drivers/gpu/drm/i915/display/intel_display_core.h:23,                                          
                  from ../drivers/gpu/drm/i915/display/intel_dp_tunnel.c:9:                                              
../drivers/gpu/drm/i915/display/intel_display_power.h:12:10: fatal error: intel_wakeref.h: No such file or directory    
    12 | #include "intel_wakeref.h"                                                                                      

because we don't setup the right include directories.
We used to test in CI a display-disabled build, not sure what happened
with that.

Lucas De Marchi

>+
> obj-$(CONFIG_DRM_XE) += xe.o
> obj-$(CONFIG_DRM_XE_KUNIT_TEST) += tests/
>
>-- 
>2.44.2
>