Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4A568C433F5 for ; Wed, 29 Dec 2021 23:44:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233390AbhL2Xof (ORCPT ); Wed, 29 Dec 2021 18:44:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43326 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232732AbhL2Xoe (ORCPT ); Wed, 29 Dec 2021 18:44:34 -0500 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E8836C061574 for ; Wed, 29 Dec 2021 15:44:33 -0800 (PST) Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 0D4FE2A5; Thu, 30 Dec 2021 00:44:31 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1640821472; bh=EKJWcHIEQZewdbTOk+cU/n4oiB8qgEvXbZQWRa+u7oY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=qduy1Zno1qWlzopoqpJQFfNnK1KAvx80kEjmRacHOZyI7MlAjMuNjJQoNF/7BMZAf LMrENXvs+3VF+pj3zMm0Vv27RfPPu2/xnOm4ClwnNVT/umlbrtagEEsQwRGOJPIGga 5i/LCNq6hS7pJ4UR2RCExD3PASGUUswmFpKCnlZE= Date: Thu, 30 Dec 2021 01:44:29 +0200 From: Laurent Pinchart To: Nikita Yushchenko Cc: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , Kieran Bingham , Jacopo Mondi , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] drm/bridge_connector: enable HPD by default if supported Message-ID: References: <20211225063151.2110878-1-nikita.yoush@cogentembedded.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20211225063151.2110878-1-nikita.yoush@cogentembedded.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Nikita, Thank you for the patch. On Sat, Dec 25, 2021 at 09:31:51AM +0300, Nikita Yushchenko wrote: > Hotplug events reported by bridge drivers over drm_bridge_hpd_notify() > get ignored unless somebody calls drm_bridge_hpd_enable(). When the > connector for the bridge is bridge_connector, such a call is done from > drm_bridge_connector_enable_hpd(). > > However drm_bridge_connector_enable_hpd() is never called on init paths, > documentation suggests that it is intended for suspend/resume paths. Hmmmm... I'm in two minds about this. The problem description is correct, but I wonder if HPD should be enabled unconditionally here, or if this should be left to display drivers to control. drivers/gpu/drm/imx/dcss/dcss-kms.c enables HPD manually at init time, other drivers don't. It feels like this should be under control of the display controller driver, but I can't think of a use case for not enabling HPD at init time. Any second opinion from anyone ? > In result, once encoders are switched to bridge_connector, > bridge-detected HPD stops working. > > This patch adds a call to that API on init path. > > This fixes HDMI HPD with rcar-du + adv7513 case when adv7513 reports HPD > events via interrupts. > > Fixes: c24110a8fd09 ("drm: rcar-du: Use drm_bridge_connector_init() helper") > Signed-off-by: Nikita Yushchenko > --- > drivers/gpu/drm/drm_bridge_connector.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/drm_bridge_connector.c b/drivers/gpu/drm/drm_bridge_connector.c > index 791379816837..4f20137ef21d 100644 > --- a/drivers/gpu/drm/drm_bridge_connector.c > +++ b/drivers/gpu/drm/drm_bridge_connector.c > @@ -369,8 +369,10 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm, > connector_type, ddc); > drm_connector_helper_add(connector, &drm_bridge_connector_helper_funcs); > > - if (bridge_connector->bridge_hpd) > + if (bridge_connector->bridge_hpd) { > connector->polled = DRM_CONNECTOR_POLL_HPD; > + drm_bridge_connector_enable_hpd(connector); > + } > else if (bridge_connector->bridge_detect) > connector->polled = DRM_CONNECTOR_POLL_CONNECT > | DRM_CONNECTOR_POLL_DISCONNECT; -- Regards, Laurent Pinchart