[1/2] drm/atomic: Allow drivers to write their own plane check for async flips

Message ID 20240116045159.1015510-2-andrealmeid@igalia.com
State New
Headers
Series drm/atomic: Allow drivers to write their own plane check for async |

Commit Message

André Almeida Jan. 16, 2024, 4:51 a.m. UTC
  Some hardware are more flexible on what they can flip asynchronously, so
rework the plane check so drivers can implement their own check, lifting
up some of the restrictions.

Signed-off-by: André Almeida <andrealmeid@igalia.com>
---
 drivers/gpu/drm/drm_atomic_uapi.c | 62 ++++++++++++++++++++++---------
 include/drm/drm_atomic_uapi.h     | 12 ++++++
 include/drm/drm_plane.h           |  5 +++
 3 files changed, 62 insertions(+), 17 deletions(-)
  

Comments

kernel test robot Jan. 19, 2024, 10:12 p.m. UTC | #1
Hi André,

kernel test robot noticed the following build warnings:

[auto build test WARNING on drm-misc/drm-misc-next]
[also build test WARNING on drm/drm-next drm-exynos/exynos-drm-next drm-intel/for-linux-next drm-tip/drm-tip linus/master next-20240119]
[cannot apply to drm-intel/for-linux-next-fixes v6.7]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Andr-Almeida/drm-atomic-Allow-drivers-to-write-their-own-plane-check-for-async-flips/20240116-125406
base:   git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
patch link:    https://lore.kernel.org/r/20240116045159.1015510-2-andrealmeid%40igalia.com
patch subject: [PATCH 1/2] drm/atomic: Allow drivers to write their own plane check for async flips
config: hexagon-randconfig-002-20240119 (https://download.01.org/0day-ci/archive/20240120/202401200526.Xggix2DE-lkp@intel.com/config)
compiler: clang version 18.0.0git (https://github.com/llvm/llvm-project d92ce344bf641e6bb025b41b3f1a77dd25e2b3e9)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240120/202401200526.Xggix2DE-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202401200526.Xggix2DE-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from drivers/gpu/drm/drm_atomic_uapi.c:31:
   In file included from include/drm/drm_atomic.h:31:
   In file included from include/drm/drm_crtc.h:32:
   In file included from include/drm/drm_modes.h:33:
   In file included from include/drm/drm_connector.h:32:
   In file included from include/drm/drm_util.h:35:
   In file included from include/linux/interrupt.h:11:
   In file included from include/linux/hardirq.h:11:
   In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
   In file included from include/asm-generic/hardirq.h:17:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:13:
   In file included from arch/hexagon/include/asm/io.h:337:
   include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     547 |         val = __raw_readb(PCI_IOBASE + addr);
         |                           ~~~~~~~~~~ ^
   include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     560 |         val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
         |                                                         ~~~~~~~~~~ ^
   include/uapi/linux/byteorder/little_endian.h:37:51: note: expanded from macro '__le16_to_cpu'
      37 | #define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
         |                                                   ^
   In file included from drivers/gpu/drm/drm_atomic_uapi.c:31:
   In file included from include/drm/drm_atomic.h:31:
   In file included from include/drm/drm_crtc.h:32:
   In file included from include/drm/drm_modes.h:33:
   In file included from include/drm/drm_connector.h:32:
   In file included from include/drm/drm_util.h:35:
   In file included from include/linux/interrupt.h:11:
   In file included from include/linux/hardirq.h:11:
   In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
   In file included from include/asm-generic/hardirq.h:17:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:13:
   In file included from arch/hexagon/include/asm/io.h:337:
   include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     573 |         val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
         |                                                         ~~~~~~~~~~ ^
   include/uapi/linux/byteorder/little_endian.h:35:51: note: expanded from macro '__le32_to_cpu'
      35 | #define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
         |                                                   ^
   In file included from drivers/gpu/drm/drm_atomic_uapi.c:31:
   In file included from include/drm/drm_atomic.h:31:
   In file included from include/drm/drm_crtc.h:32:
   In file included from include/drm/drm_modes.h:33:
   In file included from include/drm/drm_connector.h:32:
   In file included from include/drm/drm_util.h:35:
   In file included from include/linux/interrupt.h:11:
   In file included from include/linux/hardirq.h:11:
   In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
   In file included from include/asm-generic/hardirq.h:17:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:13:
   In file included from arch/hexagon/include/asm/io.h:337:
   include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     584 |         __raw_writeb(value, PCI_IOBASE + addr);
         |                             ~~~~~~~~~~ ^
   include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     594 |         __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
         |                                                       ~~~~~~~~~~ ^
   include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     604 |         __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
         |                                                       ~~~~~~~~~~ ^
>> drivers/gpu/drm/drm_atomic_uapi.c:1149:30: warning: variable 'old_val' is uninitialized when used here [-Wuninitialized]
    1149 |                                                              obj, prop_value, old_val);
         |                                                                               ^~~~~~~
   drivers/gpu/drm/drm_atomic_uapi.c:1087:13: note: initialize the variable 'old_val' to silence this warning
    1087 |         u64 old_val;
         |                    ^
         |                     = 0
   7 warnings generated.


vim +/old_val +1149 drivers/gpu/drm/drm_atomic_uapi.c

  1078	
  1079	int drm_atomic_set_property(struct drm_atomic_state *state,
  1080				    struct drm_file *file_priv,
  1081				    struct drm_mode_object *obj,
  1082				    struct drm_property *prop,
  1083				    u64 prop_value,
  1084				    bool async_flip)
  1085	{
  1086		struct drm_mode_object *ref;
  1087		u64 old_val;
  1088		int ret;
  1089	
  1090		if (!drm_property_change_valid_get(prop, prop_value, &ref))
  1091			return -EINVAL;
  1092	
  1093		switch (obj->type) {
  1094		case DRM_MODE_OBJECT_CONNECTOR: {
  1095			struct drm_connector *connector = obj_to_connector(obj);
  1096			struct drm_connector_state *connector_state;
  1097	
  1098			connector_state = drm_atomic_get_connector_state(state, connector);
  1099			if (IS_ERR(connector_state)) {
  1100				ret = PTR_ERR(connector_state);
  1101				break;
  1102			}
  1103	
  1104			if (async_flip) {
  1105				ret = drm_atomic_connector_get_property(connector, connector_state,
  1106									prop, &old_val);
  1107				ret = drm_atomic_check_prop_changes(ret, old_val, prop_value, prop);
  1108				break;
  1109			}
  1110	
  1111			ret = drm_atomic_connector_set_property(connector,
  1112					connector_state, file_priv,
  1113					prop, prop_value);
  1114			break;
  1115		}
  1116		case DRM_MODE_OBJECT_CRTC: {
  1117			struct drm_crtc *crtc = obj_to_crtc(obj);
  1118			struct drm_crtc_state *crtc_state;
  1119	
  1120			crtc_state = drm_atomic_get_crtc_state(state, crtc);
  1121			if (IS_ERR(crtc_state)) {
  1122				ret = PTR_ERR(crtc_state);
  1123				break;
  1124			}
  1125	
  1126			if (async_flip) {
  1127				ret = drm_atomic_crtc_get_property(crtc, crtc_state,
  1128								   prop, &old_val);
  1129				ret = drm_atomic_check_prop_changes(ret, old_val, prop_value, prop);
  1130				break;
  1131			}
  1132	
  1133			ret = drm_atomic_crtc_set_property(crtc,
  1134					crtc_state, prop, prop_value);
  1135			break;
  1136		}
  1137		case DRM_MODE_OBJECT_PLANE: {
  1138			struct drm_plane *plane = obj_to_plane(obj);
  1139			struct drm_plane_state *plane_state;
  1140	
  1141			plane_state = drm_atomic_get_plane_state(state, plane);
  1142			if (IS_ERR(plane_state)) {
  1143				ret = PTR_ERR(plane_state);
  1144				break;
  1145			}
  1146	
  1147			if (async_flip) {
  1148				ret = drm_atomic_check_plane_changes(prop, plane, plane_state,
> 1149								     obj, prop_value, old_val);
  1150				if (ret)
  1151					break;
  1152			}
  1153	
  1154			ret = drm_atomic_plane_set_property(plane,
  1155					plane_state, file_priv,
  1156					prop, prop_value);
  1157			break;
  1158		}
  1159		default:
  1160			drm_dbg_atomic(prop->dev, "[OBJECT:%d] has no properties\n", obj->id);
  1161			ret = -EINVAL;
  1162			break;
  1163		}
  1164	
  1165		drm_property_change_valid_put(prop, ref);
  1166		return ret;
  1167	}
  1168
  

Patch

diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
index aee4a65d4959..6d5b9fec90c7 100644
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -620,7 +620,7 @@  static int drm_atomic_plane_set_property(struct drm_plane *plane,
 	return 0;
 }
 
-static int
+int
 drm_atomic_plane_get_property(struct drm_plane *plane,
 		const struct drm_plane_state *state,
 		struct drm_property *property, uint64_t *val)
@@ -683,6 +683,7 @@  drm_atomic_plane_get_property(struct drm_plane *plane,
 
 	return 0;
 }
+EXPORT_SYMBOL(drm_atomic_plane_get_property);
 
 static int drm_atomic_set_writeback_fb_for_connector(
 		struct drm_connector_state *conn_state,
@@ -1026,18 +1027,54 @@  int drm_atomic_connector_commit_dpms(struct drm_atomic_state *state,
 	return ret;
 }
 
-static int drm_atomic_check_prop_changes(int ret, uint64_t old_val, uint64_t prop_value,
+int drm_atomic_check_prop_changes(int ret, uint64_t old_val, uint64_t prop_value,
 					 struct drm_property *prop)
 {
 	if (ret != 0 || old_val != prop_value) {
 		drm_dbg_atomic(prop->dev,
-			       "[PROP:%d:%s] No prop can be changed during async flip\n",
+			       "[PROP:%d:%s] This prop cannot be changed during async flip\n",
 			       prop->base.id, prop->name);
 		return -EINVAL;
 	}
 
 	return 0;
 }
+EXPORT_SYMBOL(drm_atomic_check_prop_changes);
+
+/* plane changes may have exceptions, so we have a special function for them */
+static int drm_atomic_check_plane_changes(struct drm_property *prop,
+					  struct drm_plane *plane,
+					  struct drm_plane_state *plane_state,
+					  struct drm_mode_object *obj,
+					  u64 prop_value, u64 old_val)
+{
+	struct drm_mode_config *config = &plane->dev->mode_config;
+	int ret;
+
+	if (plane->funcs->check_async_props)
+		return plane->funcs->check_async_props(prop, plane, plane_state,
+							     obj, prop_value, old_val);
+
+	/*
+	 * if you are trying to change something other than the FB ID, your
+	 * change will be either rejected or ignored, so we can stop the check
+	 * here
+	 */
+	if (prop != config->prop_fb_id) {
+		ret = drm_atomic_plane_get_property(plane, plane_state,
+						    prop, &old_val);
+		return drm_atomic_check_prop_changes(ret, old_val, prop_value, prop);
+	}
+
+	if (plane_state->plane->type != DRM_PLANE_TYPE_PRIMARY) {
+		drm_dbg_atomic(prop->dev,
+			       "[OBJECT:%d] Only primary planes can be changed during async flip\n",
+			       obj->id);
+		return -EINVAL;
+	}
+
+	return 0;
+}
 
 int drm_atomic_set_property(struct drm_atomic_state *state,
 			    struct drm_file *file_priv,
@@ -1100,7 +1137,6 @@  int drm_atomic_set_property(struct drm_atomic_state *state,
 	case DRM_MODE_OBJECT_PLANE: {
 		struct drm_plane *plane = obj_to_plane(obj);
 		struct drm_plane_state *plane_state;
-		struct drm_mode_config *config = &plane->dev->mode_config;
 
 		plane_state = drm_atomic_get_plane_state(state, plane);
 		if (IS_ERR(plane_state)) {
@@ -1108,19 +1144,11 @@  int drm_atomic_set_property(struct drm_atomic_state *state,
 			break;
 		}
 
-		if (async_flip && prop != config->prop_fb_id) {
-			ret = drm_atomic_plane_get_property(plane, plane_state,
-							    prop, &old_val);
-			ret = drm_atomic_check_prop_changes(ret, old_val, prop_value, prop);
-			break;
-		}
-
-		if (async_flip && plane_state->plane->type != DRM_PLANE_TYPE_PRIMARY) {
-			drm_dbg_atomic(prop->dev,
-				       "[OBJECT:%d] Only primary planes can be changed during async flip\n",
-				       obj->id);
-			ret = -EINVAL;
-			break;
+		if (async_flip) {
+			ret = drm_atomic_check_plane_changes(prop, plane, plane_state,
+							     obj, prop_value, old_val);
+			if (ret)
+				break;
 		}
 
 		ret = drm_atomic_plane_set_property(plane,
diff --git a/include/drm/drm_atomic_uapi.h b/include/drm/drm_atomic_uapi.h
index 4c6d39d7bdb2..d65fa8fbbca0 100644
--- a/include/drm/drm_atomic_uapi.h
+++ b/include/drm/drm_atomic_uapi.h
@@ -29,6 +29,8 @@ 
 #ifndef DRM_ATOMIC_UAPI_H_
 #define DRM_ATOMIC_UAPI_H_
 
+#include <linux/types.h>
+
 struct drm_crtc_state;
 struct drm_display_mode;
 struct drm_property_blob;
@@ -37,6 +39,9 @@  struct drm_crtc;
 struct drm_connector_state;
 struct dma_fence;
 struct drm_framebuffer;
+struct drm_mode_object;
+struct drm_property;
+struct drm_plane;
 
 int __must_check
 drm_atomic_set_mode_for_crtc(struct drm_crtc_state *state,
@@ -53,4 +58,11 @@  int __must_check
 drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
 				  struct drm_crtc *crtc);
 
+int drm_atomic_plane_get_property(struct drm_plane *plane,
+				  const struct drm_plane_state *state,
+				  struct drm_property *property, uint64_t *val);
+
+int drm_atomic_check_prop_changes(int ret, uint64_t old_val, uint64_t prop_value,
+				  struct drm_property *prop);
+
 #endif
diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h
index c6565a6f9324..73dac8d76831 100644
--- a/include/drm/drm_plane.h
+++ b/include/drm/drm_plane.h
@@ -540,6 +540,11 @@  struct drm_plane_funcs {
 	 */
 	bool (*format_mod_supported)(struct drm_plane *plane, uint32_t format,
 				     uint64_t modifier);
+
+	int (*check_async_props)(struct drm_property *prop, struct drm_plane *plane,
+				 struct drm_plane_state *plane_state,
+				 struct drm_mode_object *obj,
+				 u64 prop_value, u64 old_val);
 };
 
 /**