If the Adreno device is used in a headless mode, there is no need to
build all KMS components. Build corresponding parts conditionally, only
selecting them if modeset support is actually required.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 drivers/gpu/drm/msm/Kconfig       | 14 ++++++
 drivers/gpu/drm/msm/Makefile      | 16 +++----
 drivers/gpu/drm/msm/dp/dp_debug.c |  4 ++
 drivers/gpu/drm/msm/msm_debugfs.c | 92 ++++++++++++++++++++++-----------------
 drivers/gpu/drm/msm/msm_drv.h     |  7 ++-
 drivers/gpu/drm/msm/msm_kms.h     | 23 ++++++++++
 6 files changed, 108 insertions(+), 48 deletions(-)

diff --git a/drivers/gpu/drm/msm/Kconfig b/drivers/gpu/drm/msm/Kconfig
index 974bc7c0ea761147d3326bdce9039d6f26f290d0..0be31c5acdd1b7ef80f0e820ff430692616122e0 100644
--- a/drivers/gpu/drm/msm/Kconfig
+++ b/drivers/gpu/drm/msm/Kconfig
@@ -66,6 +66,14 @@ config DRM_MSM_VALIDATE_XML
 	  Validate XML files with register definitions against rules-fd schema.
 	  This option is mostly targeting DRM MSM developers. If unsure, say N.
 
+config DRM_MSM_KMS
+	def_bool n
+	depends on DRM_MSM
+
+config DRM_MSM_KMS_FBDEV
+	def_bool DRM_FBDEV_EMULATION
+	depends on DRM_MSM_KMS
+
 config DRM_MSM_MDSS
 	bool
 	depends on DRM_MSM
@@ -74,6 +82,7 @@ config DRM_MSM_MDSS
 config DRM_MSM_MDP4
 	bool "Enable MDP4 support in MSM DRM driver"
 	depends on DRM_MSM
+	select DRM_MSM_KMS
 	default y
 	help
 	  Compile in support for the Mobile Display Processor v4 (MDP4) in
@@ -84,6 +93,7 @@ config DRM_MSM_MDP5
 	bool "Enable MDP5 support in MSM DRM driver"
 	depends on DRM_MSM
 	select DRM_MSM_MDSS
+	select DRM_MSM_KMS
 	default y
 	help
 	  Compile in support for the Mobile Display Processor v5 (MDP5) in
@@ -94,6 +104,7 @@ config DRM_MSM_DPU
 	bool "Enable DPU support in MSM DRM driver"
 	depends on DRM_MSM
 	select DRM_MSM_MDSS
+	select DRM_MSM_KMS
 	select DRM_DISPLAY_DSC_HELPER
 	default y
 	help
@@ -104,6 +115,7 @@ config DRM_MSM_DPU
 config DRM_MSM_DP
 	bool "Enable DisplayPort support in MSM DRM driver"
 	depends on DRM_MSM
+	depends on DRM_MSM_KMS
 	select RATIONAL
 	default y
 	help
@@ -114,6 +126,7 @@ config DRM_MSM_DP
 config DRM_MSM_DSI
 	bool "Enable DSI support in MSM DRM driver"
 	depends on DRM_MSM
+	depends on DRM_MSM_KMS
 	select DRM_PANEL
 	select DRM_MIPI_DSI
 	select DRM_DISPLAY_DSC_HELPER
@@ -169,6 +182,7 @@ config DRM_MSM_DSI_7NM_PHY
 config DRM_MSM_HDMI
 	bool "Enable HDMI support in MSM DRM driver"
 	depends on DRM_MSM
+	depends on DRM_MSM_KMS
 	default y
 	select DRM_DISPLAY_HDMI_HELPER
 	select DRM_DISPLAY_HDMI_STATE_HELPER
diff --git a/drivers/gpu/drm/msm/Makefile b/drivers/gpu/drm/msm/Makefile
index 5df20cbeafb8bf07c825a1fd72719d5a56c38613..3749b0af779e73a93d7c219d3fbd3865b9296b50 100644
--- a/drivers/gpu/drm/msm/Makefile
+++ b/drivers/gpu/drm/msm/Makefile
@@ -101,18 +101,15 @@ msm-display-$(CONFIG_DRM_MSM_DPU) += \
 msm-display-$(CONFIG_DRM_MSM_MDSS) += \
 	msm_mdss.o \
 
-msm-display-y += \
+msm-display-$(CONFIG_DRM_MSM_KMS) += \
 	disp/mdp_format.o \
 	disp/mdp_kms.o \
 	disp/msm_disp_snapshot.o \
 	disp/msm_disp_snapshot_util.o \
 
 msm-y += \
-	msm_atomic.o \
-	msm_atomic_tracepoints.o \
 	msm_debugfs.o \
 	msm_drv.o \
-	msm_fb.o \
 	msm_fence.o \
 	msm_gem.o \
 	msm_gem_prime.o \
@@ -123,21 +120,24 @@ msm-y += \
 	msm_gpu_devfreq.o \
 	msm_io_utils.o \
 	msm_iommu.o \
-	msm_kms.o \
 	msm_perf.o \
 	msm_rd.o \
 	msm_ringbuffer.o \
 	msm_submitqueue.o \
 	msm_gpu_tracepoints.o \
 
-msm-$(CONFIG_DRM_FBDEV_EMULATION) += msm_fbdev.o
+msm-$(CONFIG_DRM_MSM_KMS) += \
+	msm_atomic.o \
+	msm_atomic_tracepoints.o \
+	msm_fb.o \
+	msm_kms.o \
 
-msm-display-$(CONFIG_DEBUG_FS) += \
-	dp/dp_debug.o
+msm-$(CONFIG_DRM_MSM_KMS_FBDEV) += msm_fbdev.o
 
 msm-display-$(CONFIG_DRM_MSM_DP)+= dp/dp_aux.o \
 	dp/dp_catalog.o \
 	dp/dp_ctrl.o \
+	dp/dp_debug.o \
 	dp/dp_display.o \
 	dp/dp_drm.o \
 	dp/dp_link.o \
diff --git a/drivers/gpu/drm/msm/dp/dp_debug.c b/drivers/gpu/drm/msm/dp/dp_debug.c
index 22fd946ee201397b72b43c8499714139deb7ba82..7835d93015b31a69aac824ca04dc65b374546e5c 100644
--- a/drivers/gpu/drm/msm/dp/dp_debug.c
+++ b/drivers/gpu/drm/msm/dp/dp_debug.c
@@ -5,6 +5,8 @@
 
 #define pr_fmt(fmt)"[drm-dp] %s: " fmt, __func__
 
+#ifdef CONFIG_DEBUG_FS
+
 #include <linux/debugfs.h>
 #include <drm/drm_connector.h>
 #include <drm/drm_file.h>
@@ -235,3 +237,5 @@ int msm_dp_debug_init(struct device *dev, struct msm_dp_panel *panel,
 
 	return 0;
 }
+
+#endif
diff --git a/drivers/gpu/drm/msm/msm_debugfs.c b/drivers/gpu/drm/msm/msm_debugfs.c
index 7ab607252d183f78b99c3a8b878c949ed5f99fec..2b12f2851fadbc3c924827e11570352736869614 100644
--- a/drivers/gpu/drm/msm/msm_debugfs.c
+++ b/drivers/gpu/drm/msm/msm_debugfs.c
@@ -117,6 +117,36 @@ static const struct file_operations msm_gpu_fops = {
 	.release = msm_gpu_release,
 };
 
+#ifdef CONFIG_DRM_MSM_KMS
+static int msm_fb_show(struct seq_file *m, void *arg)
+{
+	struct drm_info_node *node = m->private;
+	struct drm_device *dev = node->minor->dev;
+	struct drm_framebuffer *fb, *fbdev_fb = NULL;
+
+	if (dev->fb_helper && dev->fb_helper->fb) {
+		seq_puts(m, "fbcon ");
+		fbdev_fb = dev->fb_helper->fb;
+		msm_framebuffer_describe(fbdev_fb, m);
+	}
+
+	mutex_lock(&dev->mode_config.fb_lock);
+	list_for_each_entry(fb, &dev->mode_config.fb_list, head) {
+		if (fb == fbdev_fb)
+			continue;
+
+		seq_puts(m, "user ");
+		msm_framebuffer_describe(fb, m);
+	}
+	mutex_unlock(&dev->mode_config.fb_lock);
+
+	return 0;
+}
+
+static struct drm_info_list msm_kms_debugfs_list[] = {
+		{ "fb", msm_fb_show },
+};
+
 /*
  * Display Snapshot:
  */
@@ -180,6 +210,27 @@ static const struct file_operations msm_kms_fops = {
 	.release = msm_kms_release,
 };
 
+static void msm_debugfs_kms_init(struct drm_minor *minor)
+{
+	struct drm_device *dev = minor->dev;
+	struct msm_drm_private *priv = dev->dev_private;
+
+	drm_debugfs_create_files(msm_kms_debugfs_list,
+				 ARRAY_SIZE(msm_kms_debugfs_list),
+				 minor->debugfs_root, minor);
+	debugfs_create_file("kms", 0400, minor->debugfs_root,
+			    dev, &msm_kms_fops);
+
+	if (priv->kms->funcs->debugfs_init)
+		priv->kms->funcs->debugfs_init(priv->kms, minor);
+
+}
+#else /* ! CONFIG_DRM_MSM_KMS */
+static void msm_debugfs_kms_init(struct drm_minor *minor)
+{
+}
+#endif
+
 /*
  * Other debugfs:
  */
@@ -238,40 +289,11 @@ static int msm_mm_show(struct seq_file *m, void *arg)
 	return 0;
 }
 
-static int msm_fb_show(struct seq_file *m, void *arg)
-{
-	struct drm_info_node *node = m->private;
-	struct drm_device *dev = node->minor->dev;
-	struct drm_framebuffer *fb, *fbdev_fb = NULL;
-
-	if (dev->fb_helper && dev->fb_helper->fb) {
-		seq_printf(m, "fbcon ");
-		fbdev_fb = dev->fb_helper->fb;
-		msm_framebuffer_describe(fbdev_fb, m);
-	}
-
-	mutex_lock(&dev->mode_config.fb_lock);
-	list_for_each_entry(fb, &dev->mode_config.fb_list, head) {
-		if (fb == fbdev_fb)
-			continue;
-
-		seq_printf(m, "user ");
-		msm_framebuffer_describe(fb, m);
-	}
-	mutex_unlock(&dev->mode_config.fb_lock);
-
-	return 0;
-}
-
 static struct drm_info_list msm_debugfs_list[] = {
 		{"gem", msm_gem_show},
 		{ "mm", msm_mm_show },
 };
 
-static struct drm_info_list msm_kms_debugfs_list[] = {
-		{ "fb", msm_fb_show },
-};
-
 static int late_init_minor(struct drm_minor *minor)
 {
 	int ret;
@@ -343,20 +365,12 @@ void msm_debugfs_init(struct drm_minor *minor)
 	if (priv->gpu_pdev)
 		msm_debugfs_gpu_init(minor);
 
-	if (priv->kms) {
-		drm_debugfs_create_files(msm_kms_debugfs_list,
-					 ARRAY_SIZE(msm_kms_debugfs_list),
-					 minor->debugfs_root, minor);
-		debugfs_create_file("kms", S_IRUSR, minor->debugfs_root,
-				    dev, &msm_kms_fops);
-	}
+	if (priv->kms)
+		msm_debugfs_kms_init(minor);
 
 	debugfs_create_file("shrink", S_IRWXU, minor->debugfs_root,
 		dev, &shrink_fops);
 
-	if (priv->kms && priv->kms->funcs->debugfs_init)
-		priv->kms->funcs->debugfs_init(priv->kms, minor);
-
 	fault_create_debugfs_attr("fail_gem_alloc", minor->debugfs_root,
 				  &fail_gem_alloc);
 	fault_create_debugfs_attr("fail_gem_iova", minor->debugfs_root,
diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
index a65077855201746c37ee742364b61116565f3794..5f4d3f050c1fde71c405a1ebf516f4f5a396cfc4 100644
--- a/drivers/gpu/drm/msm/msm_drv.h
+++ b/drivers/gpu/drm/msm/msm_drv.h
@@ -88,6 +88,7 @@ struct msm_drm_private {
 	/* subordinate devices, if present: */
 	struct platform_device *gpu_pdev;
 
+#ifdef CONFIG_DRM_MSM_KMS
 	/* possibly this should be in the kms component, but it is
 	 * shared by both mdp4 and mdp5..
 	 */
@@ -97,6 +98,7 @@ struct msm_drm_private {
 	struct msm_dsi *dsi[MSM_DSI_CONTROLLER_COUNT];
 
 	struct msm_dp *dp[MSM_DP_CONTROLLER_COUNT];
+#endif
 
 	/* when we have more than one 'msm_gpu' these need to be an array: */
 	struct msm_gpu *gpu;
@@ -177,11 +179,13 @@ struct msm_drm_private {
 		struct mutex lock;
 	} lru;
 
+#ifdef CONFIG_DRM_MSM_KMS
 	struct workqueue_struct *wq;
 
 	unsigned int num_crtcs;
 
 	struct msm_drm_thread event_thread[MAX_CRTCS];
+#endif
 
 	/* VRAM carveout, used when no IOMMU: */
 	struct {
@@ -275,7 +279,7 @@ struct drm_framebuffer *msm_framebuffer_create(struct drm_device *dev,
 struct drm_framebuffer * msm_alloc_stolen_fb(struct drm_device *dev,
 		int w, int h, int p, uint32_t format);
 
-#ifdef CONFIG_DRM_FBDEV_EMULATION
+#ifdef CONFIG_DRM_MSM_KMS_FBDEV
 int msm_fbdev_driver_fbdev_probe(struct drm_fb_helper *helper,
 				 struct drm_fb_helper_surface_size *sizes);
 #define MSM_FBDEV_DRIVER_OPS \
@@ -360,6 +364,7 @@ static inline const char *msm_dsi_get_te_source(struct msm_dsi *msm_dsi)
 }
 #endif
 
+struct msm_dp;
 #ifdef CONFIG_DRM_MSM_DP
 int __init msm_dp_register(void);
 void __exit msm_dp_unregister(void);
diff --git a/drivers/gpu/drm/msm/msm_kms.h b/drivers/gpu/drm/msm/msm_kms.h
index 057b20367724a4ca60f2d60c038077dbcc1c7abc..aabbe851f0d533cca4a2ca00b79fbf8603870be3 100644
--- a/drivers/gpu/drm/msm/msm_kms.h
+++ b/drivers/gpu/drm/msm/msm_kms.h
@@ -13,6 +13,8 @@
 
 #include "msm_drv.h"
 
+#ifdef CONFIG_DRM_MSM_KMS
+
 #define MAX_PLANE	4
 
 /* As there are different display controller blocks depending on the
@@ -196,4 +198,25 @@ void msm_drm_kms_post_init(struct device *dev);
 void msm_drm_kms_unregister(struct device *dev);
 void msm_drm_kms_uninit(struct device *dev);
 
+#else /* ! CONFIG_DRM_MSM_KMS */
+
+static inline int msm_drm_kms_init(struct device *dev, const struct drm_driver *drv)
+{
+	return -ENODEV;
+}
+
+static inline void msm_drm_kms_post_init(struct device *dev)
+{
+}
+
+static inline void msm_drm_kms_unregister(struct device *dev)
+{
+}
+
+static inline void msm_drm_kms_uninit(struct device *dev)
+{
+}
+
+#endif
+
 #endif /* __MSM_KMS_H__ */

-- 
2.39.5

On 4/13/2025 9:32 AM, Dmitry Baryshkov wrote:
> If the Adreno device is used in a headless mode, there is no need to
> build all KMS components. Build corresponding parts conditionally, only
> selecting them if modeset support is actually required.
> 
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
> ---
>   drivers/gpu/drm/msm/Kconfig       | 14 ++++++
>   drivers/gpu/drm/msm/Makefile      | 16 +++----
>   drivers/gpu/drm/msm/dp/dp_debug.c |  4 ++
>   drivers/gpu/drm/msm/msm_debugfs.c | 92 ++++++++++++++++++++++-----------------
>   drivers/gpu/drm/msm/msm_drv.h     |  7 ++-
>   drivers/gpu/drm/msm/msm_kms.h     | 23 ++++++++++
>   6 files changed, 108 insertions(+), 48 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/Kconfig b/drivers/gpu/drm/msm/Kconfig
> index 974bc7c0ea761147d3326bdce9039d6f26f290d0..0be31c5acdd1b7ef80f0e820ff430692616122e0 100644
> --- a/drivers/gpu/drm/msm/Kconfig
> +++ b/drivers/gpu/drm/msm/Kconfig
> @@ -66,6 +66,14 @@ config DRM_MSM_VALIDATE_XML
>   	  Validate XML files with register definitions against rules-fd schema.
>   	  This option is mostly targeting DRM MSM developers. If unsure, say N.
>   
> +config DRM_MSM_KMS
> +	def_bool n
> +	depends on DRM_MSM
> +
> +config DRM_MSM_KMS_FBDEV
> +	def_bool DRM_FBDEV_EMULATION
> +	depends on DRM_MSM_KMS
> +
>   config DRM_MSM_MDSS
>   	bool
>   	depends on DRM_MSM
> @@ -74,6 +82,7 @@ config DRM_MSM_MDSS
>   config DRM_MSM_MDP4
>   	bool "Enable MDP4 support in MSM DRM driver"
>   	depends on DRM_MSM
> +	select DRM_MSM_KMS
>   	default y
>   	help
>   	  Compile in support for the Mobile Display Processor v4 (MDP4) in
> @@ -84,6 +93,7 @@ config DRM_MSM_MDP5
>   	bool "Enable MDP5 support in MSM DRM driver"
>   	depends on DRM_MSM
>   	select DRM_MSM_MDSS
> +	select DRM_MSM_KMS
>   	default y
>   	help
>   	  Compile in support for the Mobile Display Processor v5 (MDP5) in
> @@ -94,6 +104,7 @@ config DRM_MSM_DPU
>   	bool "Enable DPU support in MSM DRM driver"
>   	depends on DRM_MSM
>   	select DRM_MSM_MDSS
> +	select DRM_MSM_KMS
>   	select DRM_DISPLAY_DSC_HELPER
>   	default y
>   	help
> @@ -104,6 +115,7 @@ config DRM_MSM_DPU
>   config DRM_MSM_DP
>   	bool "Enable DisplayPort support in MSM DRM driver"
>   	depends on DRM_MSM
> +	depends on DRM_MSM_KMS
>   	select RATIONAL
>   	default y
>   	help
> @@ -114,6 +126,7 @@ config DRM_MSM_DP
>   config DRM_MSM_DSI
>   	bool "Enable DSI support in MSM DRM driver"
>   	depends on DRM_MSM
> +	depends on DRM_MSM_KMS
>   	select DRM_PANEL
>   	select DRM_MIPI_DSI
>   	select DRM_DISPLAY_DSC_HELPER
> @@ -169,6 +182,7 @@ config DRM_MSM_DSI_7NM_PHY
>   config DRM_MSM_HDMI
>   	bool "Enable HDMI support in MSM DRM driver"
>   	depends on DRM_MSM
> +	depends on DRM_MSM_KMS
>   	default y
>   	select DRM_DISPLAY_HDMI_HELPER
>   	select DRM_DISPLAY_HDMI_STATE_HELPER
> diff --git a/drivers/gpu/drm/msm/Makefile b/drivers/gpu/drm/msm/Makefile
> index 5df20cbeafb8bf07c825a1fd72719d5a56c38613..3749b0af779e73a93d7c219d3fbd3865b9296b50 100644
> --- a/drivers/gpu/drm/msm/Makefile
> +++ b/drivers/gpu/drm/msm/Makefile
> @@ -101,18 +101,15 @@ msm-display-$(CONFIG_DRM_MSM_DPU) += \
>   msm-display-$(CONFIG_DRM_MSM_MDSS) += \
>   	msm_mdss.o \
>   
> -msm-display-y += \
> +msm-display-$(CONFIG_DRM_MSM_KMS) += \
>   	disp/mdp_format.o \
>   	disp/mdp_kms.o \
>   	disp/msm_disp_snapshot.o \
>   	disp/msm_disp_snapshot_util.o \
>   
>   msm-y += \
> -	msm_atomic.o \
> -	msm_atomic_tracepoints.o \
>   	msm_debugfs.o \
>   	msm_drv.o \
> -	msm_fb.o \
>   	msm_fence.o \
>   	msm_gem.o \
>   	msm_gem_prime.o \
> @@ -123,21 +120,24 @@ msm-y += \
>   	msm_gpu_devfreq.o \
>   	msm_io_utils.o \
>   	msm_iommu.o \
> -	msm_kms.o \
>   	msm_perf.o \
>   	msm_rd.o \
>   	msm_ringbuffer.o \
>   	msm_submitqueue.o \
>   	msm_gpu_tracepoints.o \
>   
> -msm-$(CONFIG_DRM_FBDEV_EMULATION) += msm_fbdev.o
> +msm-$(CONFIG_DRM_MSM_KMS) += \
> +	msm_atomic.o \
> +	msm_atomic_tracepoints.o \
> +	msm_fb.o \
> +	msm_kms.o \
>   
> -msm-display-$(CONFIG_DEBUG_FS) += \
> -	dp/dp_debug.o
> +msm-$(CONFIG_DRM_MSM_KMS_FBDEV) += msm_fbdev.o
>   
>   msm-display-$(CONFIG_DRM_MSM_DP)+= dp/dp_aux.o \
>   	dp/dp_catalog.o \
>   	dp/dp_ctrl.o \
> +	dp/dp_debug.o \
>   	dp/dp_display.o \
>   	dp/dp_drm.o \
>   	dp/dp_link.o \
> diff --git a/drivers/gpu/drm/msm/dp/dp_debug.c b/drivers/gpu/drm/msm/dp/dp_debug.c
> index 22fd946ee201397b72b43c8499714139deb7ba82..7835d93015b31a69aac824ca04dc65b374546e5c 100644
> --- a/drivers/gpu/drm/msm/dp/dp_debug.c
> +++ b/drivers/gpu/drm/msm/dp/dp_debug.c
> @@ -5,6 +5,8 @@
>   
>   #define pr_fmt(fmt)"[drm-dp] %s: " fmt, __func__
>   
> +#ifdef CONFIG_DEBUG_FS
> +
>   #include <linux/debugfs.h>
>   #include <drm/drm_connector.h>
>   #include <drm/drm_file.h>
> @@ -235,3 +237,5 @@ int msm_dp_debug_init(struct device *dev, struct msm_dp_panel *panel,
>   
>   	return 0;
>   }
> +
> +#endif
> diff --git a/drivers/gpu/drm/msm/msm_debugfs.c b/drivers/gpu/drm/msm/msm_debugfs.c
> index 7ab607252d183f78b99c3a8b878c949ed5f99fec..2b12f2851fadbc3c924827e11570352736869614 100644
> --- a/drivers/gpu/drm/msm/msm_debugfs.c
> +++ b/drivers/gpu/drm/msm/msm_debugfs.c
> @@ -117,6 +117,36 @@ static const struct file_operations msm_gpu_fops = {
>   	.release = msm_gpu_release,
>   };
>   
> +#ifdef CONFIG_DRM_MSM_KMS
> +static int msm_fb_show(struct seq_file *m, void *arg)
> +{
> +	struct drm_info_node *node = m->private;
> +	struct drm_device *dev = node->minor->dev;
> +	struct drm_framebuffer *fb, *fbdev_fb = NULL;
> +
> +	if (dev->fb_helper && dev->fb_helper->fb) {
> +		seq_puts(m, "fbcon ");
> +		fbdev_fb = dev->fb_helper->fb;
> +		msm_framebuffer_describe(fbdev_fb, m);
> +	}
> +
> +	mutex_lock(&dev->mode_config.fb_lock);
> +	list_for_each_entry(fb, &dev->mode_config.fb_list, head) {
> +		if (fb == fbdev_fb)
> +			continue;
> +
> +		seq_puts(m, "user ");
> +		msm_framebuffer_describe(fb, m);
> +	}
> +	mutex_unlock(&dev->mode_config.fb_lock);
> +
> +	return 0;
> +}
> +
> +static struct drm_info_list msm_kms_debugfs_list[] = {
> +		{ "fb", msm_fb_show },
> +};
> +
>   /*
>    * Display Snapshot:
>    */
> @@ -180,6 +210,27 @@ static const struct file_operations msm_kms_fops = {
>   	.release = msm_kms_release,
>   };
>   
> +static void msm_debugfs_kms_init(struct drm_minor *minor)
> +{
> +	struct drm_device *dev = minor->dev;
> +	struct msm_drm_private *priv = dev->dev_private;
> +
> +	drm_debugfs_create_files(msm_kms_debugfs_list,
> +				 ARRAY_SIZE(msm_kms_debugfs_list),
> +				 minor->debugfs_root, minor);
> +	debugfs_create_file("kms", 0400, minor->debugfs_root,
> +			    dev, &msm_kms_fops);
> +
> +	if (priv->kms->funcs->debugfs_init)
> +		priv->kms->funcs->debugfs_init(priv->kms, minor);
> +
> +}
> +#else /* ! CONFIG_DRM_MSM_KMS */
> +static void msm_debugfs_kms_init(struct drm_minor *minor)
> +{
> +}
> +#endif
> +
>   /*
>    * Other debugfs:
>    */
> @@ -238,40 +289,11 @@ static int msm_mm_show(struct seq_file *m, void *arg)
>   	return 0;
>   }
>   
> -static int msm_fb_show(struct seq_file *m, void *arg)
> -{
> -	struct drm_info_node *node = m->private;
> -	struct drm_device *dev = node->minor->dev;
> -	struct drm_framebuffer *fb, *fbdev_fb = NULL;
> -
> -	if (dev->fb_helper && dev->fb_helper->fb) {
> -		seq_printf(m, "fbcon ");
> -		fbdev_fb = dev->fb_helper->fb;
> -		msm_framebuffer_describe(fbdev_fb, m);
> -	}
> -
> -	mutex_lock(&dev->mode_config.fb_lock);
> -	list_for_each_entry(fb, &dev->mode_config.fb_list, head) {
> -		if (fb == fbdev_fb)
> -			continue;
> -
> -		seq_printf(m, "user ");
> -		msm_framebuffer_describe(fb, m);
> -	}
> -	mutex_unlock(&dev->mode_config.fb_lock);
> -
> -	return 0;
> -}
> -
>   static struct drm_info_list msm_debugfs_list[] = {
>   		{"gem", msm_gem_show},
>   		{ "mm", msm_mm_show },
>   };
>   
> -static struct drm_info_list msm_kms_debugfs_list[] = {
> -		{ "fb", msm_fb_show },
> -};
> -
>   static int late_init_minor(struct drm_minor *minor)
>   {
>   	int ret;
> @@ -343,20 +365,12 @@ void msm_debugfs_init(struct drm_minor *minor)
>   	if (priv->gpu_pdev)
>   		msm_debugfs_gpu_init(minor);
>   
> -	if (priv->kms) {
> -		drm_debugfs_create_files(msm_kms_debugfs_list,
> -					 ARRAY_SIZE(msm_kms_debugfs_list),
> -					 minor->debugfs_root, minor);
> -		debugfs_create_file("kms", S_IRUSR, minor->debugfs_root,
> -				    dev, &msm_kms_fops);
> -	}
> +	if (priv->kms)
> +		msm_debugfs_kms_init(minor);
>   
>   	debugfs_create_file("shrink", S_IRWXU, minor->debugfs_root,
>   		dev, &shrink_fops);
>   
> -	if (priv->kms && priv->kms->funcs->debugfs_init)
> -		priv->kms->funcs->debugfs_init(priv->kms, minor);
> -
>   	fault_create_debugfs_attr("fail_gem_alloc", minor->debugfs_root,
>   				  &fail_gem_alloc);
>   	fault_create_debugfs_attr("fail_gem_iova", minor->debugfs_root,
> diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
> index a65077855201746c37ee742364b61116565f3794..5f4d3f050c1fde71c405a1ebf516f4f5a396cfc4 100644
> --- a/drivers/gpu/drm/msm/msm_drv.h
> +++ b/drivers/gpu/drm/msm/msm_drv.h
> @@ -88,6 +88,7 @@ struct msm_drm_private {
>   	/* subordinate devices, if present: */
>   	struct platform_device *gpu_pdev;
>   
> +#ifdef CONFIG_DRM_MSM_KMS
>   	/* possibly this should be in the kms component, but it is
>   	 * shared by both mdp4 and mdp5..
>   	 */

As the comment says, I am also thinking that this should be part of 
msm_kms struct, to avoid ifdefs. I didnt follow the second half of the 
comment that this is shared by both mdp4/mdp5. Why does that prevent it 
from being in the kms component?


> @@ -97,6 +98,7 @@ struct msm_drm_private {
>   	struct msm_dsi *dsi[MSM_DSI_CONTROLLER_COUNT];
>   
>   	struct msm_dp *dp[MSM_DP_CONTROLLER_COUNT];
> +#endif
>   
>   	/* when we have more than one 'msm_gpu' these need to be an array: */
>   	struct msm_gpu *gpu;
> @@ -177,11 +179,13 @@ struct msm_drm_private {
>   		struct mutex lock;
>   	} lru;
>   
> +#ifdef CONFIG_DRM_MSM_KMS
>   	struct workqueue_struct *wq;
>   
>   	unsigned int num_crtcs;
>   
>   	struct msm_drm_thread event_thread[MAX_CRTCS];
> +#endif
>   
>   	/* VRAM carveout, used when no IOMMU: */
>   	struct {
> @@ -275,7 +279,7 @@ struct drm_framebuffer *msm_framebuffer_create(struct drm_device *dev,
>   struct drm_framebuffer * msm_alloc_stolen_fb(struct drm_device *dev,
>   		int w, int h, int p, uint32_t format);
>   
> -#ifdef CONFIG_DRM_FBDEV_EMULATION
> +#ifdef CONFIG_DRM_MSM_KMS_FBDEV
>   int msm_fbdev_driver_fbdev_probe(struct drm_fb_helper *helper,
>   				 struct drm_fb_helper_surface_size *sizes);
>   #define MSM_FBDEV_DRIVER_OPS \
> @@ -360,6 +364,7 @@ static inline const char *msm_dsi_get_te_source(struct msm_dsi *msm_dsi)
>   }
>   #endif
>   
> +struct msm_dp;
>   #ifdef CONFIG_DRM_MSM_DP
>   int __init msm_dp_register(void);
>   void __exit msm_dp_unregister(void);
> diff --git a/drivers/gpu/drm/msm/msm_kms.h b/drivers/gpu/drm/msm/msm_kms.h
> index 057b20367724a4ca60f2d60c038077dbcc1c7abc..aabbe851f0d533cca4a2ca00b79fbf8603870be3 100644
> --- a/drivers/gpu/drm/msm/msm_kms.h
> +++ b/drivers/gpu/drm/msm/msm_kms.h
> @@ -13,6 +13,8 @@
>   
>   #include "msm_drv.h"
>   
> +#ifdef CONFIG_DRM_MSM_KMS
> +
>   #define MAX_PLANE	4
>   
>   /* As there are different display controller blocks depending on the
> @@ -196,4 +198,25 @@ void msm_drm_kms_post_init(struct device *dev);
>   void msm_drm_kms_unregister(struct device *dev);
>   void msm_drm_kms_uninit(struct device *dev);
>   
> +#else /* ! CONFIG_DRM_MSM_KMS */
> +
> +static inline int msm_drm_kms_init(struct device *dev, const struct drm_driver *drv)
> +{
> +	return -ENODEV;
> +}
> +
> +static inline void msm_drm_kms_post_init(struct device *dev)
> +{
> +}
> +
> +static inline void msm_drm_kms_unregister(struct device *dev)
> +{
> +}
> +
> +static inline void msm_drm_kms_uninit(struct device *dev)
> +{
> +}
> +
> +#endif
> +
>   #endif /* __MSM_KMS_H__ */
>

On Wed, Apr 30, 2025 at 01:09:31PM -0700, Abhinav Kumar wrote:
> 
> 
> On 4/13/2025 9:32 AM, Dmitry Baryshkov wrote:
> > If the Adreno device is used in a headless mode, there is no need to
> > build all KMS components. Build corresponding parts conditionally, only
> > selecting them if modeset support is actually required.
> > 
> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
> > ---
> >   drivers/gpu/drm/msm/Kconfig       | 14 ++++++
> >   drivers/gpu/drm/msm/Makefile      | 16 +++----
> >   drivers/gpu/drm/msm/dp/dp_debug.c |  4 ++
> >   drivers/gpu/drm/msm/msm_debugfs.c | 92 ++++++++++++++++++++++-----------------
> >   drivers/gpu/drm/msm/msm_drv.h     |  7 ++-
> >   drivers/gpu/drm/msm/msm_kms.h     | 23 ++++++++++
> >   6 files changed, 108 insertions(+), 48 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
> > index a65077855201746c37ee742364b61116565f3794..5f4d3f050c1fde71c405a1ebf516f4f5a396cfc4 100644
> > --- a/drivers/gpu/drm/msm/msm_drv.h
> > +++ b/drivers/gpu/drm/msm/msm_drv.h
> > @@ -88,6 +88,7 @@ struct msm_drm_private {
> >   	/* subordinate devices, if present: */
> >   	struct platform_device *gpu_pdev;
> > +#ifdef CONFIG_DRM_MSM_KMS
> >   	/* possibly this should be in the kms component, but it is
> >   	 * shared by both mdp4 and mdp5..
> >   	 */
> 
> As the comment says, I am also thinking that this should be part of msm_kms
> struct, to avoid ifdefs. I didnt follow the second half of the comment that
> this is shared by both mdp4/mdp5. Why does that prevent it from being in the
> kms component?

Indeed, there are no such limitations nowadays.


-- 
With best wishes
Dmitry