Commit 52e6b198 authored by Thomas Zimmermann's avatar Thomas Zimmermann
Browse files

drm/hypervdrm: Use vblank timer 



HyperV's virtual hardware does not provide vblank interrupts. Use a
vblank timer to simulate the interrupt. Rate-limits the display's
update frequency to the display-mode settings. Avoids excessive CPU
overhead with compositors that do not rate-limit their output.

Signed-off-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: default avatarJavier Martinez Canillas <javierm@redhat.com>
Tested-by: default avatarMichael Kelley <mhklinux@outlook.com>
Tested-by: default avatarPrasanna Kumar T S M <ptsm@linux.microsoft.com>
Link: https://lore.kernel.org/r/20250916083816.30275-5-tzimmermann@suse.de
parent 02e2681f

drivers/gpu/drm/hyperv/hyperv_drm_modeset.c

+11 −0
Original line number Diff line number Diff line
@@ -19,6 +19,8 @@ 
#include <drm/drm_probe_helper.h>

#include <drm/drm_panic.h>

#include <drm/drm_plane.h>

#include <drm/drm_vblank.h>

#include <drm/drm_vblank_helper.h>



#include "hyperv_drm.h"
@@ -111,11 +113,15 @@ static void hyperv_crtc_helper_atomic_enable(struct drm_crtc *crtc, 
				crtc_state->mode.hdisplay,

				crtc_state->mode.vdisplay,

				plane_state->fb->pitches[0]);



	drm_crtc_vblank_on(crtc);

}



static const struct drm_crtc_helper_funcs hyperv_crtc_helper_funcs = {

	.atomic_check = drm_crtc_helper_atomic_check,

	.atomic_flush = drm_crtc_vblank_atomic_flush,

	.atomic_enable = hyperv_crtc_helper_atomic_enable,

	.atomic_disable = drm_crtc_vblank_atomic_disable,

};



static const struct drm_crtc_funcs hyperv_crtc_funcs = {
@@ -125,6 +131,7 @@ static const struct drm_crtc_funcs hyperv_crtc_funcs = { 
	.page_flip = drm_atomic_helper_page_flip,

	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,

	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,

	DRM_CRTC_VBLANK_TIMER_FUNCS,

};



static int hyperv_plane_atomic_check(struct drm_plane *plane,
@@ -321,6 +328,10 @@ int hyperv_mode_config_init(struct hyperv_drm_device *hv) 
		return ret;

	}



	ret = drm_vblank_init(dev, 1);

	if (ret)

		return ret;



	drm_mode_config_reset(dev);



	return 0;