Nouveau - Dec 2016 - [PATCH v3 2/2] drm: Get atomic property value even if DRIVER_ATOMIC is not set

This check is useful for drivers that do not have DRIVER_ATOMIC set but
have atomic modesetting internally implemented. Wrap the check into a
function since this is used in many places and as a bonus, the function
name helps to document what the check is for.

v2:
Change return type to bool (Ville)
Move the function drm_atomic.h (Daniel)
Fixed comment marker for documentation

Suggested-by: Daniel Vetter <daniel.vetter at ffwll.ch>
Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
Cc: Ben Skeggs <bskeggs at redhat.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
---
 drivers/gpu/drm/drm_fb_helper.c             |  6 +++---
 drivers/gpu/drm/nouveau/nouveau_connector.c |  5 +++--
 drivers/gpu/drm/nouveau/nouveau_display.c   |  6 +++---
 drivers/gpu/drm/nouveau/nouveau_fbcon.c     |  3 ++-
 include/drm/drm_atomic.h                    | 12 ++++++++++++
 5 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 145d55f..730342c 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -405,7 +405,7 @@ static int restore_fbdev_mode(struct drm_fb_helper
*fb_helper)
 
 	drm_warn_on_modeset_not_all_locked(dev);
 
-	if (dev->mode_config.funcs->atomic_commit)
+	if (drm_drv_uses_atomic_modeset(dev))
 		return restore_fbdev_mode_atomic(fb_helper);
 
 	drm_for_each_plane(plane, dev) {
@@ -1444,7 +1444,7 @@ int drm_fb_helper_pan_display(struct fb_var_screeninfo
*var,
 		return -EBUSY;
 	}
 
-	if (dev->mode_config.funcs->atomic_commit) {
+	if (drm_drv_uses_atomic_modeset(dev)) {
 		ret = pan_display_atomic(var, info);
 		goto unlock;
 	}
@@ -2060,7 +2060,7 @@ static int drm_pick_crtcs(struct drm_fb_helper *fb_helper,
 	 * NULL we fallback to the default drm_atomic_helper_best_encoder()
 	 * helper.
 	 */
-	if (fb_helper->dev->mode_config.funcs->atomic_commit &&
+	if (drm_drv_uses_atomic_modeset(fb_helper->dev) &&
 	    !connector_funcs->best_encoder)
 		encoder = drm_atomic_helper_best_encoder(connector);
 	else
diff --git a/drivers/gpu/drm/nouveau/nouveau_connector.c
b/drivers/gpu/drm/nouveau/nouveau_connector.c
index 947c200..966d20a 100644
--- a/drivers/gpu/drm/nouveau/nouveau_connector.c
+++ b/drivers/gpu/drm/nouveau/nouveau_connector.c
@@ -33,6 +33,7 @@
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_crtc_helper.h>
+#include <drm/drm_atomic.h>
 
 #include "nouveau_reg.h"
 #include "nouveau_drv.h"
@@ -769,7 +770,7 @@ nouveau_connector_set_property(struct drm_connector
*connector,
 	struct drm_encoder *encoder = to_drm_encoder(nv_encoder);
 	int ret;
 
-	if (connector->dev->mode_config.funcs->atomic_commit)
+	if (drm_drv_uses_atomic_modeset(connector->dev))
 		return drm_atomic_helper_connector_set_property(connector, property, value);
 
 	ret = connector->funcs->atomic_set_property(&nv_connector->base,
@@ -1074,7 +1075,7 @@ nouveau_connector_helper_funcs = {
 static int
 nouveau_connector_dpms(struct drm_connector *connector, int mode)
 {
-	if (connector->dev->mode_config.funcs->atomic_commit)
+	if (drm_drv_uses_atomic_modeset(connector->dev))
 		return drm_atomic_helper_connector_dpms(connector, mode);
 	return drm_helper_connector_dpms(connector, mode);
 }
diff --git a/drivers/gpu/drm/nouveau/nouveau_display.c
b/drivers/gpu/drm/nouveau/nouveau_display.c
index c5cf888..add353e 100644
--- a/drivers/gpu/drm/nouveau/nouveau_display.c
+++ b/drivers/gpu/drm/nouveau/nouveau_display.c
@@ -162,7 +162,7 @@ nouveau_display_vblstamp(struct drm_device *dev, unsigned
int pipe,
 	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
 		if (nouveau_crtc(crtc)->index == pipe) {
 			struct drm_display_mode *mode;
-			if (dev->mode_config.funcs->atomic_commit)
+			if (drm_drv_uses_atomic_modeset(dev))
 				mode = &crtc->state->adjusted_mode;
 			else
 				mode = &crtc->hwmode;
@@ -738,7 +738,7 @@ nouveau_display_suspend(struct drm_device *dev, bool
runtime)
 	struct nouveau_display *disp = nouveau_display(dev);
 	struct drm_crtc *crtc;
 
-	if (dev->mode_config.funcs->atomic_commit) {
+	if (drm_drv_uses_atomic_modeset(dev)) {
 		if (!runtime) {
 			disp->suspend = nouveau_atomic_suspend(dev);
 			if (IS_ERR(disp->suspend)) {
@@ -784,7 +784,7 @@ nouveau_display_resume(struct drm_device *dev, bool runtime)
 	struct drm_crtc *crtc;
 	int ret;
 
-	if (dev->mode_config.funcs->atomic_commit) {
+	if (drm_drv_uses_atomic_modeset(dev)) {
 		nouveau_display_init(dev);
 		if (disp->suspend) {
 			drm_atomic_helper_resume(dev, disp->suspend);
diff --git a/drivers/gpu/drm/nouveau/nouveau_fbcon.c
b/drivers/gpu/drm/nouveau/nouveau_fbcon.c
index 5600f6c..9de6abb 100644
--- a/drivers/gpu/drm/nouveau/nouveau_fbcon.c
+++ b/drivers/gpu/drm/nouveau/nouveau_fbcon.c
@@ -41,6 +41,7 @@
 #include <drm/drm_crtc.h>
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_fb_helper.h>
+#include <drm/drm_atomic.h>
 
 #include "nouveau_drv.h"
 #include "nouveau_gem.h"
@@ -524,7 +525,7 @@ nouveau_fbcon_init(struct drm_device *dev)
 		preferred_bpp = 32;
 
 	/* disable all the possible outputs/crtcs before entering KMS mode */
-	if (!dev->mode_config.funcs->atomic_commit)
+	if (!drm_drv_uses_atomic_modeset(dev))
 		drm_helper_disable_unused_functions(dev);
 
 	ret = drm_fb_helper_initial_config(&fbcon->helper, preferred_bpp);
diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
index 8cc7ca2..fb5bf07 100644
--- a/include/drm/drm_atomic.h
+++ b/include/drm/drm_atomic.h
@@ -419,5 +419,17 @@ drm_atomic_crtc_needs_modeset(const struct drm_crtc_state
*state)
 	       state->connectors_changed;
 }
 
+/**
+ * drm_drv_uses_atomic_modeset - check if the driver implements
+ * atomic_commit()
+ * @dev: DRM device
+ *
+ * This check is useful if drivers do not have DRIVER_ATOMIC set but
+ * have atomic modesetting internally implemented.
+ */
+static inline bool drm_drv_uses_atomic_modeset(struct drm_device *dev)
+{
+	return dev->mode_config.funcs->atomic_commit != NULL;
+}
 
 #endif /* DRM_ATOMIC_H_ */
-- 
2.7.4

i915 does not set DRIVER_ATOMIC by default yet but uses atomic_check and
atomic_commit. drm_object_property_get_value() does not read the correct
value of atomic properties if DRIVER_ATOMIC is not set. Checking whether
the driver uses atomic modeset is a better check instead as the property
values are tracked in the state structures.

v2: Included header

Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
---
 drivers/gpu/drm/drm_mode_object.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_mode_object.c
b/drivers/gpu/drm/drm_mode_object.c
index 9f17085..14543ff 100644
--- a/drivers/gpu/drm/drm_mode_object.c
+++ b/drivers/gpu/drm/drm_mode_object.c
@@ -23,6 +23,7 @@
 #include <linux/export.h>
 #include <drm/drmP.h>
 #include <drm/drm_mode_object.h>
+#include <drm/drm_atomic.h>
 
 #include "drm_crtc_internal.h"
 
@@ -273,7 +274,7 @@ int drm_object_property_get_value(struct drm_mode_object
*obj,
 	 * their value in obj->properties->values[].. mostly to avoid
 	 * having to deal w/ EDID and similar props in atomic paths:
 	 */
-	if (drm_core_check_feature(property->dev, DRIVER_ATOMIC) &&
+	if (drm_drv_uses_atomic_modeset(property->dev) &&
 			!(property->flags & DRM_MODE_PROP_IMMUTABLE))
 		return drm_atomic_get_property(obj, property, val);
 
-- 
2.7.4

Hi Dhinakaran,

[auto build test ERROR on drm/drm-next]
[also build test ERROR on next-20161222]
[cannot apply to v4.9]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system]

url:   
https://github.com/0day-ci/linux/commits/Dhinakaran-Pandiyan/drm-Wrap-the-check-for-atomic_commit-implementation/20161222-174536
base:   git://people.freedesktop.org/~airlied/linux.git drm-next
config: openrisc-allmodconfig (attached as .config)
compiler: or32-linux-gcc (GCC) 4.5.1-or32-1.0rc1
reproduce:
        wget
https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross
-O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=openrisc 

All errors (new ones prefixed by >>):

   In file included from drivers/gpu/drm/vc4/vc4_crtc.c:34:0:
   include/drm/drm_atomic.h: In function
'drm_drv_uses_atomic_modeset':
>> include/drm/drm_atomic.h:437:12: error: dereferencing pointer to
incomplete type
vim +437 include/drm/drm_atomic.h

   431	 *
   432	 * This check is useful if drivers do not have DRIVER_ATOMIC set but
   433	 * have atomic modesetting internally implemented.
   434	 */
   435	static inline bool drm_drv_uses_atomic_modeset(struct drm_device *dev)
   436	{
 > 437		return dev->mode_config.funcs->atomic_commit != NULL;
   438	}
   439	
   440	#endif /* DRM_ATOMIC_H_ */

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
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On Fri, Dec 23, 2016 at 12:29:11AM +0800, kbuild test robot
wrote:
> Hi Dhinakaran,
> 
> [auto build test ERROR on drm/drm-next]
> [also build test ERROR on next-20161222]
> [cannot apply to v4.9]
> [if your patch is applied to the wrong git tree, please drop us a note to
help improve the system]
> 
> url:   
https://github.com/0day-ci/linux/commits/Dhinakaran-Pandiyan/drm-Wrap-the-check-for-atomic_commit-implementation/20161222-174536
> base:   git://people.freedesktop.org/~airlied/linux.git drm-next
> config: openrisc-allmodconfig (attached as .config)
> compiler: or32-linux-gcc (GCC) 4.5.1-or32-1.0rc1
> reproduce:
>         wget
https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross
-O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # save the attached .config to linux build tree
>         make.cross ARCH=openrisc 
> 
> All errors (new ones prefixed by >>):
> 
>    In file included from drivers/gpu/drm/vc4/vc4_crtc.c:34:0:
>    include/drm/drm_atomic.h: In function
'drm_drv_uses_atomic_modeset':
> >> include/drm/drm_atomic.h:437:12: error: dereferencing pointer to
incomplete type
Sorry for the silliness, but sounds like we need to move this little
helper back to drmP.h unfortunately. I'll do that while applying.
-Daniel
> 
> vim +437 include/drm/drm_atomic.h
> 
>    431	 *
>    432	 * This check is useful if drivers do not have DRIVER_ATOMIC set but
>    433	 * have atomic modesetting internally implemented.
>    434	 */
>    435	static inline bool drm_drv_uses_atomic_modeset(struct drm_device
*dev)
>    436	{
>  > 437		return dev->mode_config.funcs->atomic_commit != NULL;
>    438	}
>    439	
>    440	#endif /* DRM_ATOMIC_H_ */
> 
> ---
> 0-DAY kernel test infrastructure                Open Source Technology
Center
> https://lists.01.org/pipermail/kbuild-all                   Intel
Corporation


-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

On Thu, Dec 22, 2016 at 12:50:43AM -0800, Dhinakaran Pandiyan
wrote:
> i915 does not set DRIVER_ATOMIC by default yet but uses atomic_check and
> atomic_commit. drm_object_property_get_value() does not read the correct
> value of atomic properties if DRIVER_ATOMIC is not set. Checking whether
> the driver uses atomic modeset is a better check instead as the property
> values are tracked in the state structures.
> 
> v2: Included header
> 
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
Both applied to drm-misc, thanks.
-Daniel
> ---
>  drivers/gpu/drm/drm_mode_object.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/drm_mode_object.c
b/drivers/gpu/drm/drm_mode_object.c
> index 9f17085..14543ff 100644
> --- a/drivers/gpu/drm/drm_mode_object.c
> +++ b/drivers/gpu/drm/drm_mode_object.c
> @@ -23,6 +23,7 @@
>  #include <linux/export.h>
>  #include <drm/drmP.h>
>  #include <drm/drm_mode_object.h>
> +#include <drm/drm_atomic.h>
>  
>  #include "drm_crtc_internal.h"
>  
> @@ -273,7 +274,7 @@ int drm_object_property_get_value(struct
drm_mode_object *obj,
>  	 * their value in obj->properties->values[].. mostly to avoid
>  	 * having to deal w/ EDID and similar props in atomic paths:
>  	 */
> -	if (drm_core_check_feature(property->dev, DRIVER_ATOMIC) &&
> +	if (drm_drv_uses_atomic_modeset(property->dev) &&
>  			!(property->flags & DRM_MODE_PROP_IMMUTABLE))
>  		return drm_atomic_get_property(obj, property, val);
>  
> -- 
> 2.7.4
> 
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch