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Commit 0f3bbe07 authored by Maxime Ripard's avatar Maxime Ripard Committed by Daniel Vetter
Browse files

drm/fb-helper: implement ioctl FBIO_WAITFORVSYNC 



Implement legacy framebuffer ioctl FBIO_WAITFORVSYNC in the generic
framebuffer emulation driver. Legacy framebuffer users like non kms/drm
based OpenGL(ES)/EGL implementations may require the ioctl to
synchronize drawing or buffer flip for double buffering. It is tested on
the i.MX6.

Signed-off-by: default avatarMaxime Ripard <maxime.ripard@free-electrons.com>
Tested-by: default avatarNeil Armstrong <narmstrong@baylibre.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent 35f5022f

drivers/gpu/drm/drm_fb_helper.c

+68 −0
Original line number Diff line number Diff line
@@ -1244,6 +1244,74 @@ int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info) 
}

EXPORT_SYMBOL(drm_fb_helper_setcmap);



/**

 * drm_fb_helper_ioctl - legacy ioctl implementation

 * @info: fbdev registered by the helper

 * @cmd: ioctl command

 * @arg: ioctl argument

 *

 * A helper to implement the standard fbdev ioctl. Only

 * FBIO_WAITFORVSYNC is implemented for now.

 */

int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,

			unsigned long arg)

{

	struct drm_fb_helper *fb_helper = info->par;

	struct drm_device *dev = fb_helper->dev;

	struct drm_mode_set *mode_set;

	struct drm_crtc *crtc;

	int ret = 0;



	mutex_lock(&dev->mode_config.mutex);

	if (!drm_fb_helper_is_bound(fb_helper)) {

		ret = -EBUSY;

		goto unlock;

	}



	switch (cmd) {

	case FBIO_WAITFORVSYNC:

		/*

		 * Only consider the first CRTC.

		 *

		 * This ioctl is supposed to take the CRTC number as

		 * an argument, but in fbdev times, what that number

		 * was supposed to be was quite unclear, different

		 * drivers were passing that argument differently

		 * (some by reference, some by value), and most of the

		 * userspace applications were just hardcoding 0 as an

		 * argument.

		 *

		 * The first CRTC should be the integrated panel on

		 * most drivers, so this is the best choice we can

		 * make. If we're not smart enough here, one should

		 * just consider switch the userspace to KMS.

		 */

		mode_set = &fb_helper->crtc_info[0].mode_set;

		crtc = mode_set->crtc;



		/*

		 * Only wait for a vblank event if the CRTC is

		 * enabled, otherwise just don't do anythintg,

		 * not even report an error.

		 */

		ret = drm_crtc_vblank_get(crtc);

		if (!ret) {

			drm_crtc_wait_one_vblank(crtc);

			drm_crtc_vblank_put(crtc);

		}



		ret = 0;

		goto unlock;

	default:

		ret = -ENOTTY;

	}



unlock:

	mutex_unlock(&dev->mode_config.mutex);

	return ret;

}

EXPORT_SYMBOL(drm_fb_helper_ioctl);



/**

 * drm_fb_helper_check_var - implementation for &fb_ops.fb_check_var

 * @var: screeninfo to check

include/drm/drm_fb_helper.h

+11 −1
Original line number Diff line number Diff line
@@ -230,7 +230,8 @@ struct drm_fb_helper { 
	.fb_blank	= drm_fb_helper_blank, \

	.fb_pan_display	= drm_fb_helper_pan_display, \

	.fb_debug_enter = drm_fb_helper_debug_enter, \

	.fb_debug_leave = drm_fb_helper_debug_leave

	.fb_debug_leave = drm_fb_helper_debug_leave, \

	.fb_ioctl	= drm_fb_helper_ioctl



#ifdef CONFIG_DRM_FBDEV_EMULATION

void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
@@ -284,6 +285,9 @@ void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper, 


int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info);



int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,

			unsigned long arg);



int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper);

int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel);

int drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper);
@@ -371,6 +375,12 @@ static inline int drm_fb_helper_setcmap(struct fb_cmap *cmap, 
	return 0;

}



static inline int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,

				      unsigned long arg)

{

	return 0;

}



static inline void drm_fb_helper_unlink_fbi(struct drm_fb_helper *fb_helper)

{

}