diff mbox

[v4,1/1] drm/fb-helper: implement ioctl FBIO_WAITFORVSYNC

Message ID 9f67ae4055ab0bc093d7d94e503a0d6d1909d856.1488296169.git-series.maxime.ripard@free-electrons.com (mailing list archive)
State New, archived
Headers show

Commit Message

Maxime Ripard Feb. 28, 2017, 3:36 p.m. UTC
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: Maxime Ripard <maxime.ripard@free-electrons.com>
Tested-by: Neil Armstrong <narmstrong@baylibre.com>
---
 drivers/gpu/drm/drm_fb_helper.c | 68 ++++++++++++++++++++++++++++++++++-
 include/drm/drm_fb_helper.h     | 12 +++++-
 2 files changed, 79 insertions(+), 1 deletion(-)

Comments

Stefan Lengfeld March 1, 2017, 9:31 p.m. UTC | #1
Hi Maxime,

On Tue, Feb 28, 2017 at 04:36:51PM +0100, Maxime Ripard wrote:
> 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: Maxime Ripard <maxime.ripard@free-electrons.com>
> Tested-by: Neil Armstrong <narmstrong@baylibre.com>

I will test this patch and the already applied patch to drm-next on the
i.MX6 platform in the next days.

Kind regards,
    Stefan
Daniel Vetter March 2, 2017, 7:12 a.m. UTC | #2
On Tue, Feb 28, 2017 at 04:36:51PM +0100, Maxime Ripard wrote:
> 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: Maxime Ripard <maxime.ripard@free-electrons.com>
> Tested-by: Neil Armstrong <narmstrong@baylibre.com>

Pushed to drm-misc, thanks.
-Daniel

> ---
>  drivers/gpu/drm/drm_fb_helper.c | 68 ++++++++++++++++++++++++++++++++++-
>  include/drm/drm_fb_helper.h     | 12 +++++-
>  2 files changed, 79 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
> index c6de87abaca8..8ac8716c023a 100644
> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c
> @@ -1240,6 +1240,74 @@ 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_check_var
>   * @var: screeninfo to check
>   * @info: fbdev registered by the helper
> diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
> index 975deedd593e..2891888c6e41 100644
> --- a/include/drm/drm_fb_helper.h
> +++ b/include/drm/drm_fb_helper.h
> @@ -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,
> @@ -286,6 +287,9 @@ 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);
> @@ -377,6 +381,12 @@ 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)
>  {
>  }
> -- 
> git-series 0.8.11
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
Daniel Vetter March 2, 2017, 10:09 a.m. UTC | #3
On Thu, Mar 02, 2017 at 08:12:02AM +0100, Daniel Vetter wrote:
> On Tue, Feb 28, 2017 at 04:36:51PM +0100, Maxime Ripard wrote:
> > 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: Maxime Ripard <maxime.ripard@free-electrons.com>
> > Tested-by: Neil Armstrong <narmstrong@baylibre.com>
> 
> Pushed to drm-misc, thanks.

I forgot to add Dave's irc ack to the commit patch, but for the record I
discussed it with him and he's not enthuastic, but ok.
-Daniel

> -Daniel
> 
> > ---
> >  drivers/gpu/drm/drm_fb_helper.c | 68 ++++++++++++++++++++++++++++++++++-
> >  include/drm/drm_fb_helper.h     | 12 +++++-
> >  2 files changed, 79 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
> > index c6de87abaca8..8ac8716c023a 100644
> > --- a/drivers/gpu/drm/drm_fb_helper.c
> > +++ b/drivers/gpu/drm/drm_fb_helper.c
> > @@ -1240,6 +1240,74 @@ 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_check_var
> >   * @var: screeninfo to check
> >   * @info: fbdev registered by the helper
> > diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
> > index 975deedd593e..2891888c6e41 100644
> > --- a/include/drm/drm_fb_helper.h
> > +++ b/include/drm/drm_fb_helper.h
> > @@ -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,
> > @@ -286,6 +287,9 @@ 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);
> > @@ -377,6 +381,12 @@ 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)
> >  {
> >  }
> > -- 
> > git-series 0.8.11
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/dri-devel
> 
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
Stefan Lengfeld March 5, 2017, 10:23 p.m. UTC | #4
Hi Maxime,

On Tue, Feb 28, 2017 at 04:36:51PM +0100, Maxime Ripard wrote:
> 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: Maxime Ripard <maxime.ripard@free-electrons.com>
> Tested-by: Neil Armstrong <narmstrong@baylibre.com>
> ---
>  drivers/gpu/drm/drm_fb_helper.c | 68 ++++++++++++++++++++++++++++++++++-
>  include/drm/drm_fb_helper.h     | 12 +++++-
>  2 files changed, 79 insertions(+), 1 deletion(-)

I have tested the current HEAD of drm-misc-next. It includes this patch
and the patch ("drm/fb-helper: Add multi buffer support for cma fbdev").
On my i.MX6 board with HDMI output both patches work as advertised.
Multi-buffering with ioctls FBIO_WAITFORVSYNC and FBIOPAN_DISPLAY is
possible.

Kind Regards
    Stefan Lengfeld
diff mbox

Patch

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index c6de87abaca8..8ac8716c023a 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1240,6 +1240,74 @@  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_check_var
  * @var: screeninfo to check
  * @info: fbdev registered by the helper
diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
index 975deedd593e..2891888c6e41 100644
--- a/include/drm/drm_fb_helper.h
+++ b/include/drm/drm_fb_helper.h
@@ -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,
@@ -286,6 +287,9 @@  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);
@@ -377,6 +381,12 @@  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)
 {
 }