On 29-10-2025 13:45, Kandpal, Suraj wrote:
Subject: [PATCH v6 4/5] drm/atomic: Return user readable error in atomic_ioctlAdd user readable error codes for failure cases in drm_atomic_ioctl() so that user can decode the error code and take corrective measurements. Signed-off-by: Arun R Murthy <[email protected]> --- drivers/gpu/drm/drm_atomic_uapi.c | 71 ++++++++++++++++++++++++++++----------- 1 file changed, 52 insertions(+), 19 deletions(-) diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c index 3ef478e717bec917d1b8803c72bbcc8d6409d745..3d4e9709e8e289cf302413 e171b1336812d65c1c 100644 --- a/drivers/gpu/drm/drm_atomic_uapi.c +++ b/drivers/gpu/drm/drm_atomic_uapi.c @@ -1036,6 +1036,11 @@ int drm_atomic_set_property(struct drm_atomic_state *state, ret = drm_atomic_connector_get_property(connector, connector_state, prop, &old_val); ret = drm_atomic_check_prop_changes(ret, old_val, prop_value, prop); + if (ret) { + drm_mode_atomic_add_error_msg(&state-error_code,+ DRM_MODE_ATOMIC_ASYNC_PROP_CHANGED, + "property change not allowed in async flip"); + } break; } @@ -1058,6 +1063,11 @@ int drm_atomic_set_property(struct drm_atomic_state *state, ret = drm_atomic_crtc_get_property(crtc, crtc_state, prop, &old_val); ret = drm_atomic_check_prop_changes(ret, old_val, prop_value, prop); + if (ret) { + drm_mode_atomic_add_error_msg(&state-error_code,+ DRM_MODE_ATOMIC_ASYNC_PROP_CHANGED, + "property change not allowed in async flip"); + } break; } @@ -1096,9 +1106,10 @@ int drm_atomic_set_property(struct drm_atomic_state *state, ret = plane_funcs-atomic_async_check(plane, state, true);if (ret) { - drm_dbg_atomic(prop->dev, - "[PLANE:%d:%s] does not support async flips\n", - obj->id, plane->name); + drm_mode_atomic_add_error_msg(&state->error_code, + DRM_MODE_ATOMIC_ASYNC_NOT_SUPP_PLANE, + "[PLANE:%d:%s] does not support async flip", + obj->id, plane->name); break; } } @@ -1393,6 +1404,7 @@ int drm_mode_atomic_ioctl(struct drm_device *dev, struct drm_atomic_state *state; struct drm_modeset_acquire_ctx ctx; struct drm_out_fence_state *fence_state; + struct drm_mode_atomic_err_code __user *error_code_ptr; int ret = 0; unsigned int i, j, num_fences = 0; bool async_flip = false; @@ -1401,6 +1413,14 @@ int drm_mode_atomic_ioctl(struct drm_device *dev, if (!drm_core_check_feature(dev, DRIVER_ATOMIC)) return -EOPNOTSUPP; + if (!arg->reserved) + drm_dbg_atomic(dev, + "memory not allocated for drm_atomic error reporting\n"); + else + /* update the error code if any error to allow user handling it */First letter in uppercase.
Done!
+ error_code_ptr = (struct drm_mode_atomic_err_code __user *) + (unsigned long)arg->reserved; + state = drm_atomic_state_alloc(dev); if (!state) return -ENOMEM; @@ -1409,31 +1429,35 @@ int drm_mode_atomic_ioctl(struct drm_device *dev, state->acquire_ctx = &ctx; state->allow_modeset = !!(arg->flags & DRM_MODE_ATOMIC_ALLOW_MODESET); + memset(&state->error_code, 0, sizeof(struct +drm_mode_atomic_err_code));Isn't is better to have it as sizeof(*error_code_ptr)
Done!
+ /* disallow for userspace that has not enabled atomic cap (even * though this may be a bit overkill, since legacy userspace * wouldn't know how to call this ioctl) */ if (!file_priv->atomic) { - drm_dbg_atomic(dev, - "commit failed: atomic cap not enabled\n"); - return -EINVAL; + drm_mode_atomic_add_error_msg(&state->error_code, + DRM_MODE_ATOMIC_INVALID_API_USAGE, + "DRM_ATOMIC capability not enabled");I'd rather have it say drm atomic capability not enabled
Done!
+ ret = -EINVAL; + goto out; } if (arg->flags & ~DRM_MODE_ATOMIC_FLAGS) { - drm_dbg_atomic(dev, "commit failed: invalid flag\n"); - return -EINVAL; - } - - if (arg->reserved) { - drm_dbg_atomic(dev, "commit failed: reserved field set\n"); - return -EINVAL; + drm_mode_atomic_add_error_msg(&state->error_code, + DRM_MODE_ATOMIC_INVALID_API_USAGE, + "invalid flag"); + ret = -EINVAL; + goto out; } if (arg->flags & DRM_MODE_PAGE_FLIP_ASYNC) { if (!dev->mode_config.async_page_flip) { - drm_dbg_atomic(dev, - "commit failed: DRM_MODE_PAGE_FLIP_ASYNC not supported\n"); - return -EINVAL; + drm_mode_atomic_add_error_msg(&state-error_code,+ DRM_MODE_ATOMIC_INVALID_API_USAGE, + "DRM_MODE_PAGE_FLIP_ASYNC not supported with ATOMIC ioctl"); + ret = -EINVAL; + goto out; } async_flip = true; @@ -1442,9 +1466,11 @@ int drm_mode_atomic_ioctl(struct drm_device *dev, /* can't test and expect an event at the same time. */ if ((arg->flags & DRM_MODE_ATOMIC_TEST_ONLY) && (arg->flags & DRM_MODE_PAGE_FLIP_EVENT)) { - drm_dbg_atomic(dev, - "commit failed: page-flip event requested with test-only commit\n"); - return -EINVAL; + drm_mode_atomic_add_error_msg(&state->error_code, + DRM_MODE_ATOMIC_INVALID_API_USAGE, + "page-flip event requested with test-only commit"); + ret = -EINVAL; + goto out; } retry: @@ -1543,6 +1569,13 @@ int drm_mode_atomic_ioctl(struct drm_device *dev, } out: + /* update the error code if any error to allow user handling it */First letter in uppercase here
Done! Thanks and Regards, Arun R Murthy -------------------
Regards, Suraj Kandpal+ if (ret < 0 && arg->reserved) { + if (copy_to_user(error_code_ptr, &state->error_code, + sizeof(state->error_code))) + return -EFAULT; + } + if (num_fences) complete_signaling(dev, state, fence_state, num_fences, !ret); -- 2.25.1
