From 1c26b8e09004477c070f0dccb2369438ef9e1fc9 Mon Sep 17 00:00:00 2001 From: Lyude Paul Date: Mon, 13 Jul 2020 13:07:45 -0400 Subject: drm/probe_helper: Add drm_connector_helper_funcs.mode_valid_ctx This is just an atomic version of mode_valid, which is intended to be used for situations where a driver might need to check the atomic state of objects other than the connector itself. One such example is with MST, where the maximum possible bandwidth on a connector can change dynamically irregardless of the display configuration. Changes since v1: * Use new drm logging functions * Make some corrections in the mode_valid_ctx kdoc * Return error codes or 0 from ->mode_valid_ctx() on fail, and store the drm_mode_status in an additional function parameter Changes since v2: * Don't accidentally assign ret to mode->status on success, or we'll squash legitimate mode validation results * Don't forget to assign MODE_OK to status in drm_connector_mode_valid() if we have no callbacks * Drop leftover hunk in drm_modes.h around enum drm_mode_status Changes since v3: * s/return ret/return 0/ in drm_mode_validate_pipeline() * Minor cleanup in drm_connector_mode_valid() Tested-by: Imre Deak Reviewed-by: Imre Deak Cc: Lee Shawn C Signed-off-by: Lyude Paul Link: https://patchwork.freedesktop.org/patch/msgid/20200713170746.254388-2-lyude@redhat.com --- drivers/gpu/drm/drm_crtc_helper_internal.h | 7 ++- drivers/gpu/drm/drm_probe_helper.c | 97 ++++++++++++++++++++---------- include/drm/drm_modeset_helper_vtables.h | 42 +++++++++++++ 3 files changed, 111 insertions(+), 35 deletions(-) diff --git a/drivers/gpu/drm/drm_crtc_helper_internal.h b/drivers/gpu/drm/drm_crtc_helper_internal.h index f0a66ef47e5a..25ce42e79995 100644 --- a/drivers/gpu/drm/drm_crtc_helper_internal.h +++ b/drivers/gpu/drm/drm_crtc_helper_internal.h @@ -73,8 +73,11 @@ enum drm_mode_status drm_crtc_mode_valid(struct drm_crtc *crtc, const struct drm_display_mode *mode); enum drm_mode_status drm_encoder_mode_valid(struct drm_encoder *encoder, const struct drm_display_mode *mode); -enum drm_mode_status drm_connector_mode_valid(struct drm_connector *connector, - struct drm_display_mode *mode); +int +drm_connector_mode_valid(struct drm_connector *connector, + struct drm_display_mode *mode, + struct drm_modeset_acquire_ctx *ctx, + enum drm_mode_status *status); struct drm_encoder * drm_connector_get_single_encoder(struct drm_connector *connector); diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c index 26e997f1524f..601a4f25bb47 100644 --- a/drivers/gpu/drm/drm_probe_helper.c +++ b/drivers/gpu/drm/drm_probe_helper.c @@ -86,17 +86,19 @@ drm_mode_validate_flag(const struct drm_display_mode *mode, return MODE_OK; } -static enum drm_mode_status +static int drm_mode_validate_pipeline(struct drm_display_mode *mode, - struct drm_connector *connector) + struct drm_connector *connector, + struct drm_modeset_acquire_ctx *ctx, + enum drm_mode_status *status) { struct drm_device *dev = connector->dev; - enum drm_mode_status ret = MODE_OK; struct drm_encoder *encoder; + int ret; /* Step 1: Validate against connector */ - ret = drm_connector_mode_valid(connector, mode); - if (ret != MODE_OK) + ret = drm_connector_mode_valid(connector, mode, ctx, status); + if (ret || *status != MODE_OK) return ret; /* Step 2: Validate against encoders and crtcs */ @@ -104,8 +106,8 @@ drm_mode_validate_pipeline(struct drm_display_mode *mode, struct drm_bridge *bridge; struct drm_crtc *crtc; - ret = drm_encoder_mode_valid(encoder, mode); - if (ret != MODE_OK) { + *status = drm_encoder_mode_valid(encoder, mode); + if (*status != MODE_OK) { /* No point in continuing for crtc check as this encoder * will not accept the mode anyway. If all encoders * reject the mode then, at exit, ret will not be @@ -114,8 +116,8 @@ drm_mode_validate_pipeline(struct drm_display_mode *mode, } bridge = drm_bridge_chain_get_first_bridge(encoder); - ret = drm_bridge_chain_mode_valid(bridge, mode); - if (ret != MODE_OK) { + *status = drm_bridge_chain_mode_valid(bridge, mode); + if (*status != MODE_OK) { /* There is also no point in continuing for crtc check * here. */ continue; @@ -125,17 +127,17 @@ drm_mode_validate_pipeline(struct drm_display_mode *mode, if (!drm_encoder_crtc_ok(encoder, crtc)) continue; - ret = drm_crtc_mode_valid(crtc, mode); - if (ret == MODE_OK) { + *status = drm_crtc_mode_valid(crtc, mode); + if (*status == MODE_OK) { /* If we get to this point there is at least * one combination of encoder+crtc that works * for this mode. Lets return now. */ - return ret; + return 0; } } } - return ret; + return 0; } static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector) @@ -196,16 +198,27 @@ enum drm_mode_status drm_encoder_mode_valid(struct drm_encoder *encoder, return encoder_funcs->mode_valid(encoder, mode); } -enum drm_mode_status drm_connector_mode_valid(struct drm_connector *connector, - struct drm_display_mode *mode) +int +drm_connector_mode_valid(struct drm_connector *connector, + struct drm_display_mode *mode, + struct drm_modeset_acquire_ctx *ctx, + enum drm_mode_status *status) { const struct drm_connector_helper_funcs *connector_funcs = connector->helper_private; + int ret = 0; + + if (!connector_funcs) + *status = MODE_OK; + else if (connector_funcs->mode_valid_ctx) + ret = connector_funcs->mode_valid_ctx(connector, mode, ctx, + status); + else if (connector_funcs->mode_valid) + *status = connector_funcs->mode_valid(connector, mode); + else + *status = MODE_OK; - if (!connector_funcs || !connector_funcs->mode_valid) - return MODE_OK; - - return connector_funcs->mode_valid(connector, mode); + return ret; } #define DRM_OUTPUT_POLL_PERIOD (10*HZ) @@ -375,8 +388,9 @@ EXPORT_SYMBOL(drm_helper_probe_detect); * (if specified) * - drm_mode_validate_flag() checks the modes against basic connector * capabilities (interlace_allowed,doublescan_allowed,stereo_allowed) - * - the optional &drm_connector_helper_funcs.mode_valid helper can perform - * driver and/or sink specific checks + * - the optional &drm_connector_helper_funcs.mode_valid or + * &drm_connector_helper_funcs.mode_valid_ctx helpers can perform driver + * and/or sink specific checks * - the optional &drm_crtc_helper_funcs.mode_valid, * &drm_bridge_funcs.mode_valid and &drm_encoder_helper_funcs.mode_valid * helpers can perform driver and/or source specific checks which are also @@ -507,22 +521,39 @@ retry: mode_flags |= DRM_MODE_FLAG_3D_MASK; list_for_each_entry(mode, &connector->modes, head) { - if (mode->status == MODE_OK) - mode->status = drm_mode_validate_driver(dev, mode); + if (mode->status != MODE_OK) + continue; + + mode->status = drm_mode_validate_driver(dev, mode); + if (mode->status != MODE_OK) + continue; - if (mode->status == MODE_OK) - mode->status = drm_mode_validate_size(mode, maxX, maxY); + mode->status = drm_mode_validate_size(mode, maxX, maxY); + if (mode->status != MODE_OK) + continue; - if (mode->status == MODE_OK) - mode->status = drm_mode_validate_flag(mode, mode_flags); + mode->status = drm_mode_validate_flag(mode, mode_flags); + if (mode->status != MODE_OK) + continue; - if (mode->status == MODE_OK) - mode->status = drm_mode_validate_pipeline(mode, - connector); + ret = drm_mode_validate_pipeline(mode, connector, &ctx, + &mode->status); + if (ret) { + drm_dbg_kms(dev, + "drm_mode_validate_pipeline failed: %d\n", + ret); + + if (drm_WARN_ON_ONCE(dev, ret != -EDEADLK)) { + mode->status = MODE_ERROR; + } else { + drm_modeset_backoff(&ctx); + goto retry; + } + } - if (mode->status == MODE_OK) - mode->status = drm_mode_validate_ycbcr420(mode, - connector); + if (mode->status != MODE_OK) + continue; + mode->status = drm_mode_validate_ycbcr420(mode, connector); } prune: diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h index 421a30f08463..4efec30f8bad 100644 --- a/include/drm/drm_modeset_helper_vtables.h +++ b/include/drm/drm_modeset_helper_vtables.h @@ -968,6 +968,48 @@ struct drm_connector_helper_funcs { */ enum drm_mode_status (*mode_valid)(struct drm_connector *connector, struct drm_display_mode *mode); + + /** + * @mode_valid_ctx: + * + * Callback to validate a mode for a connector, irrespective of the + * specific display configuration. + * + * This callback is used by the probe helpers to filter the mode list + * (which is usually derived from the EDID data block from the sink). + * See e.g. drm_helper_probe_single_connector_modes(). + * + * This function is optional, and is the atomic version of + * &drm_connector_helper_funcs.mode_valid. + * + * To allow for accessing the atomic state of modesetting objects, the + * helper libraries always call this with ctx set to a valid context, + * and &drm_mode_config.connection_mutex will always be locked with + * the ctx parameter set to @ctx. This allows for taking additional + * locks as required. + * + * Even though additional locks may be acquired, this callback is + * still expected not to take any constraints into account which would + * be influenced by the currently set display state - such constraints + * should be handled in the driver's atomic check. For example, if a + * connector shares display bandwidth with other connectors then it + * would be ok to validate the minimum bandwidth requirement of a mode + * against the maximum possible bandwidth of the connector. But it + * wouldn't be ok to take the current bandwidth usage of other + * connectors into account, as this would change depending on the + * display state. + * + * Returns: + * 0 if &drm_connector_helper_funcs.mode_valid_ctx succeeded and wrote + * the &enum drm_mode_status value to @status, or a negative error + * code otherwise. + * + */ + int (*mode_valid_ctx)(struct drm_connector *connector, + struct drm_display_mode *mode, + struct drm_modeset_acquire_ctx *ctx, + enum drm_mode_status *status); + /** * @best_encoder: * -- cgit v1.2.3