Commit b55f3bba authored by Thomas Zimmermann's avatar Thomas Zimmermann Committed by Jani Nikula
Browse files

drm/{i915, xe}: Implement fbdev emulation as in-kernel client 



Replace all code that initializes or releases fbdev emulation
throughout the driver. Instead initialize the fbdev client by a
single call to intel_fbdev_setup() after i915 has registered its
DRM device. Just like similar code in other drivers, i915 fbdev
emulation now acts like a regular DRM client. Do the same for xe.

The fbdev client setup consists of the initial preparation and the
hot-plugging of the display. The latter creates the fbdev device
and sets up the fbdev framebuffer. The setup performs display
hot-plugging once. If no display can be detected, DRM probe helpers
re-run the detection on each hotplug event.

A call to drm_client_dev_unregister() releases all in-kernel clients
automatically. No further action is required within i915. If the fbdev
framebuffer has been fully set up, struct fb_ops.fb_destroy implements
the release. For partially initialized emulation, the fbdev client
reverts the initial setup. Do the same for xe and remove its call to
intel_fbdev_fini().

v8:
- setup client in intel_display_driver_register (Jouni)
- mention xe in commit message

v7:
- update xe driver
- reword commit message

v6:
- use 'i915' for i915 device (Jouni)
- remove unnecessary code for non-atomic mode setting (Jouni, Ville)
- fix function name in commit message (Jouni)

v3:
-  as before, silently ignore devices without displays

v2:
-  let drm_client_register() handle initial hotplug
-  fix driver name in error message (Jani)
-  fix non-fbdev build (kernel test robot)

Signed-off-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: default avatarJouni Högander <jouni.hogander@intel.com>
Acked-by: default avatarLucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240409081029.17843-7-tzimmermann@suse.de


Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
parent 762f8c13

drivers/gpu/drm/i915/display/intel_display.c

+0 −1
Original line number Diff line number Diff line
@@ -85,7 +85,6 @@ 
#include "intel_dvo.h"

#include "intel_fb.h"

#include "intel_fbc.h"

#include "intel_fbdev.h"

#include "intel_fdi.h"

#include "intel_fifo_underrun.h"

#include "intel_frontbuffer.h"

drivers/gpu/drm/i915/display/intel_display_driver.c

+2 −18
Original line number Diff line number Diff line
@@ -516,10 +516,6 @@ int intel_display_driver_probe(struct drm_i915_private *i915) 


	intel_overlay_setup(i915);



	ret = intel_fbdev_init(&i915->drm);

	if (ret)

		return ret;



	/* Only enable hotplug handling once the fbdev is fully set up. */

	intel_hpd_init(i915);
@@ -546,16 +542,6 @@ void intel_display_driver_register(struct drm_i915_private *i915) 


	intel_display_debugfs_register(i915);



	/*

	 * Some ports require correctly set-up hpd registers for

	 * detection to work properly (leading to ghost connected

	 * connector status), e.g. VGA on gm45.  Hence we can only set

	 * up the initial fbdev config after hpd irqs are fully

	 * enabled. We do it last so that the async config cannot run

	 * before the connectors are registered.

	 */

	intel_fbdev_initial_config_async(i915);



	/*

	 * We need to coordinate the hotplugs with the asynchronous

	 * fbdev configuration, for which we use the
@@ -564,6 +550,8 @@ void intel_display_driver_register(struct drm_i915_private *i915) 
	drm_kms_helper_poll_init(&i915->drm);

	intel_hpd_poll_disable(i915);



	intel_fbdev_setup(i915);



	intel_display_device_info_print(DISPLAY_INFO(i915),

					DISPLAY_RUNTIME_INFO(i915), &p);

}
@@ -599,9 +587,6 @@ void intel_display_driver_remove_noirq(struct drm_i915_private *i915) 
	 */

	intel_hpd_poll_fini(i915);



	/* poll work can call into fbdev, hence clean that up afterwards */

	intel_fbdev_fini(i915);



	intel_unregister_dsm_handler();



	/* flush any delayed tasks or pending work */
@@ -642,7 +627,6 @@ void intel_display_driver_unregister(struct drm_i915_private *i915) 


	drm_client_dev_unregister(&i915->drm);



	intel_fbdev_unregister(i915);

	/*

	 * After flushing the fbdev (incl. a late async config which

	 * will have delayed queuing of a hotplug event), then flush

drivers/gpu/drm/i915/display/intel_fbdev.c

+76 −101
Original line number Diff line number Diff line
@@ -24,7 +24,6 @@ 
 *     David Airlie

 */



#include <linux/async.h>

#include <linux/console.h>

#include <linux/delay.h>

#include <linux/errno.h>
@@ -39,6 +38,7 @@ 
#include <linux/vga_switcheroo.h>



#include <drm/drm_crtc.h>

#include <drm/drm_crtc_helper.h>

#include <drm/drm_fb_helper.h>

#include <drm/drm_fourcc.h>

#include <drm/drm_gem_framebuffer_helper.h>
@@ -58,7 +58,6 @@ struct intel_fbdev { 
	struct intel_framebuffer *fb;

	struct i915_vma *vma;

	unsigned long vma_flags;

	async_cookie_t cookie;

	int preferred_bpp;



	/* Whether or not fbdev hpd processing is temporarily suspended */
@@ -135,6 +134,26 @@ static int intel_fbdev_mmap(struct fb_info *info, struct vm_area_struct *vma) 
	return i915_gem_fb_mmap(obj, vma);

}



static void intel_fbdev_fb_destroy(struct fb_info *info)

{

	struct drm_fb_helper *fb_helper = info->par;

	struct intel_fbdev *ifbdev = container_of(fb_helper, struct intel_fbdev, helper);



	drm_fb_helper_fini(&ifbdev->helper);



	/*

	 * We rely on the object-free to release the VMA pinning for

	 * the info->screen_base mmaping. Leaking the VMA is simpler than

	 * trying to rectify all the possible error paths leading here.

	 */

	intel_unpin_fb_vma(ifbdev->vma, ifbdev->vma_flags);

	drm_framebuffer_remove(&ifbdev->fb->base);



	drm_client_release(&fb_helper->client);

	drm_fb_helper_unprepare(&ifbdev->helper);

	kfree(ifbdev);

}



__diag_push();

__diag_ignore_all("-Woverride-init", "Allow field initialization overrides for fb ops");
@@ -147,6 +166,7 @@ static const struct fb_ops intelfb_ops = { 
	.fb_pan_display = intel_fbdev_pan_display,

	__FB_DEFAULT_DEFERRED_OPS_DRAW(intel_fbdev),

	.fb_mmap = intel_fbdev_mmap,

	.fb_destroy = intel_fbdev_fb_destroy,

};



__diag_pop();
@@ -158,7 +178,6 @@ static int intelfb_create(struct drm_fb_helper *helper, 
	struct intel_framebuffer *intel_fb = ifbdev->fb;

	struct drm_device *dev = helper->dev;

	struct drm_i915_private *dev_priv = to_i915(dev);

	struct pci_dev *pdev = to_pci_dev(dev_priv->drm.dev);

	const struct i915_gtt_view view = {

		.type = I915_GTT_VIEW_NORMAL,

	};
@@ -250,7 +269,7 @@ static int intelfb_create(struct drm_fb_helper *helper, 
	ifbdev->vma_flags = flags;



	intel_runtime_pm_put(&dev_priv->runtime_pm, wakeref);

	vga_switcheroo_client_fb_set(pdev, info);



	return 0;



out_unpin:
@@ -276,26 +295,6 @@ static const struct drm_fb_helper_funcs intel_fb_helper_funcs = { 
	.fb_dirty = intelfb_dirty,

};



static void intel_fbdev_destroy(struct intel_fbdev *ifbdev)

{

	/* We rely on the object-free to release the VMA pinning for

	 * the info->screen_base mmaping. Leaking the VMA is simpler than

	 * trying to rectify all the possible error paths leading here.

	 */



	drm_fb_helper_fini(&ifbdev->helper);



	if (ifbdev->vma)

		intel_unpin_fb_vma(ifbdev->vma, ifbdev->vma_flags);



	if (ifbdev->fb)

		drm_framebuffer_remove(&ifbdev->fb->base);



	drm_client_release(&ifbdev->helper.client);

	drm_fb_helper_unprepare(&ifbdev->helper);

	kfree(ifbdev);

}



/*

 * Build an intel_fbdev struct using a BIOS allocated framebuffer, if possible.

 * The core display code will have read out the current plane configuration,
@@ -459,16 +458,6 @@ static void intel_fbdev_suspend_worker(struct work_struct *work) 
				true);

}



static void intel_fbdev_sync(struct intel_fbdev *ifbdev)

{

	if (!ifbdev->cookie)

		return;



	/* Only serialises with all preceding async calls, hence +1 */

	async_synchronize_cookie(ifbdev->cookie + 1);

	ifbdev->cookie = 0;

}



/* Suspends/resumes fbdev processing of incoming HPD events. When resuming HPD

 * processing, fbdev will perform a full connector reprobe if a hotplug event

 * was received while HPD was suspended.
@@ -559,8 +548,6 @@ static int intel_fbdev_output_poll_changed(struct drm_device *dev) 
	if (!ifbdev)

		return -EINVAL;



	intel_fbdev_sync(ifbdev);



	mutex_lock(&ifbdev->hpd_lock);

	send_hpd = !ifbdev->hpd_suspended;

	ifbdev->hpd_waiting = true;
@@ -580,7 +567,6 @@ static int intel_fbdev_restore_mode(struct drm_i915_private *dev_priv) 
	if (!ifbdev)

		return -EINVAL;



	intel_fbdev_sync(ifbdev);

	if (!ifbdev->vma)

		return -ENOMEM;
@@ -598,7 +584,20 @@ static int intel_fbdev_restore_mode(struct drm_i915_private *dev_priv) 
 */



static void intel_fbdev_client_unregister(struct drm_client_dev *client)

{ }

{

	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);

	struct drm_device *dev = fb_helper->dev;

	struct pci_dev *pdev = to_pci_dev(dev->dev);



	if (fb_helper->info) {

		vga_switcheroo_client_fb_set(pdev, NULL);

		drm_fb_helper_unregister_info(fb_helper);

	} else {

		drm_fb_helper_unprepare(fb_helper);

		drm_client_release(&fb_helper->client);

		kfree(fb_helper);

	}

}



static int intel_fbdev_client_restore(struct drm_client_dev *client)

{
@@ -616,7 +615,31 @@ static int intel_fbdev_client_restore(struct drm_client_dev *client) 


static int intel_fbdev_client_hotplug(struct drm_client_dev *client)

{

	return intel_fbdev_output_poll_changed(client->dev);

	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);

	struct drm_device *dev = client->dev;

	struct pci_dev *pdev = to_pci_dev(dev->dev);

	int ret;



	if (dev->fb_helper)

		return intel_fbdev_output_poll_changed(dev);



	ret = drm_fb_helper_init(dev, fb_helper);

	if (ret)

		goto err_drm_err;



	ret = drm_fb_helper_initial_config(fb_helper);

	if (ret)

		goto err_drm_fb_helper_fini;



	vga_switcheroo_client_fb_set(pdev, fb_helper->info);



	return 0;



err_drm_fb_helper_fini:

	drm_fb_helper_fini(fb_helper);

err_drm_err:

	drm_err(dev, "Failed to setup i915 fbdev emulation (ret=%d)\n", ret);

	return ret;

}



static const struct drm_client_funcs intel_fbdev_client_funcs = {
@@ -626,22 +649,23 @@ static const struct drm_client_funcs intel_fbdev_client_funcs = { 
	.hotplug	= intel_fbdev_client_hotplug,

};



int intel_fbdev_init(struct drm_device *dev)

void intel_fbdev_setup(struct drm_i915_private *i915)

{

	struct drm_i915_private *dev_priv = to_i915(dev);

	struct drm_device *dev = &i915->drm;

	struct intel_fbdev *ifbdev;

	int ret;



	if (drm_WARN_ON(dev, !HAS_DISPLAY(dev_priv)))

		return -ENODEV;

	if (!HAS_DISPLAY(i915))

		return;



	ifbdev = kzalloc(sizeof(*ifbdev), GFP_KERNEL);

	if (!ifbdev)

		return -ENOMEM;



	mutex_init(&ifbdev->hpd_lock);

		return;

	drm_fb_helper_prepare(dev, &ifbdev->helper, 32, &intel_fb_helper_funcs);



	i915->display.fbdev.fbdev = ifbdev;

	INIT_WORK(&i915->display.fbdev.suspend_work, intel_fbdev_suspend_worker);

	mutex_init(&ifbdev->hpd_lock);

	if (intel_fbdev_init_bios(dev, ifbdev))

		ifbdev->helper.preferred_bpp = ifbdev->preferred_bpp;

	else
@@ -649,68 +673,19 @@ int intel_fbdev_init(struct drm_device *dev) 


	ret = drm_client_init(dev, &ifbdev->helper.client, "intel-fbdev",

			      &intel_fbdev_client_funcs);

	if (ret)

	if (ret) {

		drm_err(dev, "Failed to register client: %d\n", ret);

		goto err_drm_fb_helper_unprepare;

	}



	ret = drm_fb_helper_init(dev, &ifbdev->helper);

	if (ret)

		goto err_drm_client_release;



	dev_priv->display.fbdev.fbdev = ifbdev;

	INIT_WORK(&dev_priv->display.fbdev.suspend_work, intel_fbdev_suspend_worker);

	drm_client_register(&ifbdev->helper.client);



	return 0;

	return;



err_drm_client_release:

	drm_client_release(&ifbdev->helper.client);

err_drm_fb_helper_unprepare:

	drm_fb_helper_unprepare(&ifbdev->helper);

	mutex_destroy(&ifbdev->hpd_lock);

	kfree(ifbdev);

	return ret;

}



static void intel_fbdev_initial_config(void *data, async_cookie_t cookie)

{

	struct intel_fbdev *ifbdev = data;



	/* Due to peculiar init order wrt to hpd handling this is separate. */

	if (drm_fb_helper_initial_config(&ifbdev->helper))

		intel_fbdev_unregister(to_i915(ifbdev->helper.dev));

}



void intel_fbdev_initial_config_async(struct drm_i915_private *dev_priv)

{

	struct intel_fbdev *ifbdev = dev_priv->display.fbdev.fbdev;



	if (!ifbdev)

		return;



	ifbdev->cookie = async_schedule(intel_fbdev_initial_config, ifbdev);

}



void intel_fbdev_unregister(struct drm_i915_private *dev_priv)

{

	struct intel_fbdev *ifbdev = dev_priv->display.fbdev.fbdev;



	if (!ifbdev)

		return;



	intel_fbdev_set_suspend(&dev_priv->drm, FBINFO_STATE_SUSPENDED, true);



	if (!current_is_async())

		intel_fbdev_sync(ifbdev);



	drm_fb_helper_unregister_info(&ifbdev->helper);

}



void intel_fbdev_fini(struct drm_i915_private *dev_priv)

{

	struct intel_fbdev *ifbdev = fetch_and_zero(&dev_priv->display.fbdev.fbdev);



	if (!ifbdev)

		return;



	intel_fbdev_destroy(ifbdev);

}



struct intel_framebuffer *intel_fbdev_framebuffer(struct intel_fbdev *fbdev)

drivers/gpu/drm/i915/display/intel_fbdev.h

+2 −18
Original line number Diff line number Diff line
@@ -14,27 +14,11 @@ struct intel_fbdev; 
struct intel_framebuffer;



#ifdef CONFIG_DRM_FBDEV_EMULATION

int intel_fbdev_init(struct drm_device *dev);

void intel_fbdev_initial_config_async(struct drm_i915_private *dev_priv);

void intel_fbdev_unregister(struct drm_i915_private *dev_priv);

void intel_fbdev_fini(struct drm_i915_private *dev_priv);

void intel_fbdev_setup(struct drm_i915_private *dev_priv);

void intel_fbdev_set_suspend(struct drm_device *dev, int state, bool synchronous);

struct intel_framebuffer *intel_fbdev_framebuffer(struct intel_fbdev *fbdev);

#else

static inline int intel_fbdev_init(struct drm_device *dev)

{

	return 0;

}



static inline void intel_fbdev_initial_config_async(struct drm_i915_private *dev_priv)

{

}



static inline void intel_fbdev_unregister(struct drm_i915_private *dev_priv)

{

}



static inline void intel_fbdev_fini(struct drm_i915_private *dev_priv)

static inline void intel_fbdev_setup(struct drm_i915_private *dev_priv)

{

}

drivers/gpu/drm/xe/display/xe_display.c

+0 −2
Original line number Diff line number Diff line
@@ -214,9 +214,7 @@ void xe_display_fini(struct xe_device *xe) 
	if (!xe->info.enable_display)

		return;



	/* poll work can call into fbdev, hence clean that up afterwards */

	intel_hpd_poll_fini(xe);

	intel_fbdev_fini(xe);



	intel_hdcp_component_fini(xe);

	intel_audio_deinit(xe);