From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 216B0C4338F for ; Thu, 19 Aug 2021 17:15:35 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9911D60200 for ; Thu, 19 Aug 2021 17:15:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 9911D60200 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ravnborg.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id EEB376E8F8; Thu, 19 Aug 2021 17:15:33 +0000 (UTC) Received: from mx1.smtp.larsendata.com (mx1.smtp.larsendata.com [91.221.196.215]) by gabe.freedesktop.org (Postfix) with ESMTPS id E554B6E8F8 for ; Thu, 19 Aug 2021 17:15:31 +0000 (UTC) Received: from mail01.mxhotel.dk (mail01.mxhotel.dk [91.221.196.236]) by mx1.smtp.larsendata.com (Halon) with ESMTPS id 074459fe-0111-11ec-b37b-0050568c148b; Thu, 19 Aug 2021 17:15:18 +0000 (UTC) Received: from ravnborg.org (80-162-45-141-cable.dk.customer.tdc.net [80.162.45.141]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: sam@ravnborg.org) by mail01.mxhotel.dk (Postfix) with ESMTPSA id 64A04194B17; Thu, 19 Aug 2021 19:15:38 +0200 (CEST) Date: Thu, 19 Aug 2021 19:15:25 +0200 X-Report-Abuse-To: abuse@mxhotel.dk From: Sam Ravnborg To: Maxime Ripard Cc: dri-devel@lists.freedesktop.org, Daniel Vetter , David Airlie , Maarten Lankhorst , Thomas Zimmermann , linux-rpi-kernel@lists.infradead.org, Emma Anholt , bcm-kernel-feedback-list@broadcom.com, Nicolas Saenz Julienne , Dave Stevenson , Phil Elwell , Tim Gover , Dom Cobley , linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] drm/probe-helper: Create a HPD IRQ event helper for a single connector Message-ID: References: <20210819134454.850031-1-maxime@cerno.tech> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210819134454.850031-1-maxime@cerno.tech> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi Maxime, a few comments in the following that I hope you will find useful. Sam On Thu, Aug 19, 2021 at 03:44:53PM +0200, Maxime Ripard wrote: > The drm_helper_hpd_irq_event() function is iterating over all the > connectors when an hotplug event is detected. > > During that iteration, it will call each connector detect function and > figure out if its status changed. > > Finally, if any connector changed, it will notify the user-space and the > clients that something changed on the DRM device. > > This is supposed to be used for drivers that don't have a hotplug > interrupt for individual connectors. However, drivers that can use an > interrupt for a single connector are left in the dust and can either > reimplement the logic used during the iteration for each connector or > use that helper and iterate over all connectors all the time. > > Since both are suboptimal, let's create a helper that will only perform > the status detection on a single connector. > > Signed-off-by: Maxime Ripard > --- > drivers/gpu/drm/drm_probe_helper.c | 105 ++++++++++++++++++++--------- > include/drm/drm_probe_helper.h | 1 + > 2 files changed, 74 insertions(+), 32 deletions(-) > > diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c > index 5606bca3caa8..7e3cbb4333ce 100644 > --- a/drivers/gpu/drm/drm_probe_helper.c > +++ b/drivers/gpu/drm/drm_probe_helper.c > @@ -795,6 +795,77 @@ void drm_kms_helper_poll_fini(struct drm_device *dev) > } > EXPORT_SYMBOL(drm_kms_helper_poll_fini); > > +static bool > +_drm_connector_helper_hpd_irq_event(struct drm_connector *connector, > + bool notify) I hate _names _starting _with '_'. In this case check_connector_changed() would be better IMO. Also the notify bool could be dropped, just move the notify code to the drm_connector_helper_hpd_irq_event(). > +{ > + struct drm_device *dev = connector->dev; > + enum drm_connector_status old_status; > + u64 old_epoch_counter; > + bool changed = false; > + > + /* Only handle HPD capable connectors. */ > + drm_WARN_ON(dev, !(connector->polled & DRM_CONNECTOR_POLL_HPD)); > + > + drm_WARN_ON(dev, !mutex_is_locked(&dev->mode_config.mutex)); > + > + old_status = connector->status; > + old_epoch_counter = connector->epoch_counter; > + > + DRM_DEBUG_KMS("[CONNECTOR:%d:%s] Old epoch counter %llu\n", > + connector->base.id, > + connector->name, > + old_epoch_counter); As you touch this code please use the new drm_dbg_kms() macro for logging. > + > + connector->status = drm_helper_probe_detect(connector, NULL, > + false); > + DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n", > + connector->base.id, > + connector->name, > + drm_get_connector_status_name(old_status), > + drm_get_connector_status_name(connector->status)); > + > + DRM_DEBUG_KMS("[CONNECTOR:%d:%s] New epoch counter %llu\n", > + connector->base.id, > + connector->name, > + connector->epoch_counter); > + > + /* > + * Check if epoch counter had changed, meaning that we need > + * to send a uevent. > + */ > + if (old_epoch_counter != connector->epoch_counter) > + changed = true; > + > + if (changed && notify) { > + drm_kms_helper_hotplug_event(dev); > + DRM_DEBUG_KMS("Sent hotplug event\n"); > + } > + > + return changed; > +} > + > +/** > + * drm_connector_helper_hpd_irq_event - hotplug processing > + * @connector: drm_connector > + * > + * Drivers can use this helper function to run a detect cycle on a connector > + * which has the DRM_CONNECTOR_POLL_HPD flag set in its &polled member. > + * > + * This helper function is useful for drivers which can track hotplug > + * interrupts for a single connector. > + * > + * This function must be called with the mode setting locks held. > + * > + * Note that a connector can be both polled and probed from the hotplug > + * handler, in case the hotplug interrupt is known to be unreliable. > + */ > +bool drm_connector_helper_hpd_irq_event(struct drm_connector *connector) > +{ > + return _drm_connector_helper_hpd_irq_event(connector, true); > +} > +EXPORT_SYMBOL(drm_connector_helper_hpd_irq_event); > + > /** > * drm_helper_hpd_irq_event - hotplug processing > * @dev: drm_device > @@ -822,9 +893,7 @@ bool drm_helper_hpd_irq_event(struct drm_device *dev) > { > struct drm_connector *connector; > struct drm_connector_list_iter conn_iter; > - enum drm_connector_status old_status; > bool changed = false; > - u64 old_epoch_counter; > > if (!dev->mode_config.poll_enabled) > return false; > @@ -832,37 +901,9 @@ bool drm_helper_hpd_irq_event(struct drm_device *dev) > mutex_lock(&dev->mode_config.mutex); > drm_connector_list_iter_begin(dev, &conn_iter); > drm_for_each_connector_iter(connector, &conn_iter) { > - /* Only handle HPD capable connectors. */ > - if (!(connector->polled & DRM_CONNECTOR_POLL_HPD)) > - continue; > - > - old_status = connector->status; > - > - old_epoch_counter = connector->epoch_counter; > - > - DRM_DEBUG_KMS("[CONNECTOR:%d:%s] Old epoch counter %llu\n", connector->base.id, > - connector->name, > - old_epoch_counter); > - > - connector->status = drm_helper_probe_detect(connector, NULL, false); > - DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n", > - connector->base.id, > - connector->name, > - drm_get_connector_status_name(old_status), > - drm_get_connector_status_name(connector->status)); > - > - DRM_DEBUG_KMS("[CONNECTOR:%d:%s] New epoch counter %llu\n", > - connector->base.id, > - connector->name, > - connector->epoch_counter); > - > - /* > - * Check if epoch counter had changed, meaning that we need > - * to send a uevent. > - */ > - if (old_epoch_counter != connector->epoch_counter) > + if (_drm_connector_helper_hpd_irq_event(connector, > + false)) > changed = true; > - > } > drm_connector_list_iter_end(&conn_iter); > mutex_unlock(&dev->mode_config.mutex); > diff --git a/include/drm/drm_probe_helper.h b/include/drm/drm_probe_helper.h > index 8d3ed2834d34..04c57564c397 100644 > --- a/include/drm/drm_probe_helper.h > +++ b/include/drm/drm_probe_helper.h > @@ -18,6 +18,7 @@ int drm_helper_probe_detect(struct drm_connector *connector, > void drm_kms_helper_poll_init(struct drm_device *dev); > void drm_kms_helper_poll_fini(struct drm_device *dev); > bool drm_helper_hpd_irq_event(struct drm_device *dev); > +bool drm_connector_helper_hpd_irq_event(struct drm_connector *connector); > void drm_kms_helper_hotplug_event(struct drm_device *dev); > > void drm_kms_helper_poll_disable(struct drm_device *dev); > -- > 2.31.1