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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 9C5D3ECE560 for ; Mon, 17 Sep 2018 21:12:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 48B662086E for ; Mon, 17 Sep 2018 21:12:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 48B662086E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728498AbeIRClL (ORCPT ); Mon, 17 Sep 2018 22:41:11 -0400 Received: from mail-qk1-f193.google.com ([209.85.222.193]:45075 "EHLO mail-qk1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727698AbeIRClL (ORCPT ); Mon, 17 Sep 2018 22:41:11 -0400 Received: by mail-qk1-f193.google.com with SMTP id z125-v6so9818282qkb.12 for ; Mon, 17 Sep 2018 14:12:06 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:subject:from:reply-to:to:cc:date :in-reply-to:references:organization:mime-version :content-transfer-encoding; bh=9JcuwktUPxGorXIdDuG7FppZmYysYFYmhEz2Cf2OeXQ=; b=VkqISfxBcXrWkYjs106aXGMr3HcKYrKoujDV3B+IAebUXX3cf7tLJvQhbjB4Wr6TZi GEPx8qpfCx2+jcZ308WufKHIl9ry6o6B8idZcZLVum+TrIi8oshzmsnXY5uOTE4Ycxq8 HV3sH4zo5OrQQ/XVVRfx6ZiB9W9uuCBs8FQHwYd4TUBraWwq3qD+bUr9Iwz9t22Pwl+V PqdV2o78RVw6CkTtnv7VTah53yDsyj3Zjpn/OEja+oOQWeBquzXS71bbI6bQ+LxFQShk j75YAdo63vGEYWVvGS67E65tRJQvgC7gIjmXGxSmX/4P2ml88RooH0L8HsoyXrUIv8CB T7sg== X-Gm-Message-State: APzg51C7QGyx7lsgX1qL76mwngUgeI6nbZqcKKJyD0r/R/eM6HaDLnzZ TUDkmg1xHKVNxKeS9E2KGiFL6zPDi1E= X-Google-Smtp-Source: ANB0VdZoM7jPhQXci8bpqqUmg5MbOp+gaYYHxrMToTOh5fKMnOWwi0ua9n01H8PxUjK4LVHRDtkQxA== X-Received: by 2002:a37:c845:: with SMTP id c66-v6mr17602350qkj.65.1537218726209; Mon, 17 Sep 2018 14:12:06 -0700 (PDT) Received: from whitewolf.lyude.net (pool-72-74-165-95.bstnma.fios.verizon.net. [72.74.165.95]) by smtp.gmail.com with ESMTPSA id d138-v6sm8765229qke.18.2018.09.17.14.12.05 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 17 Sep 2018 14:12:05 -0700 (PDT) Message-ID: <8773991abd73242bc4ff27c5f1ac35eaaf40a72c.camel@redhat.com> Subject: Re: [PATCH] drm/probe_helper: Don't bother probing when connectors are forced off From: Lyude Paul Reply-To: lyude@redhat.com To: Ville =?ISO-8859-1?Q?Syrj=E4l=E4?= Cc: dri-devel@lists.freedesktop.org, Sean Paul , David Airlie , linux-kernel@vger.kernel.org Date: Mon, 17 Sep 2018 17:12:04 -0400 In-Reply-To: <20180917181641.GQ5565@intel.com> References: <20180917174344.22011-1-lyude@redhat.com> <20180917175545.GP5565@intel.com> <54c01a13f382aacd7cd4d75a642630053f54b8f1.camel@redhat.com> <20180917181641.GQ5565@intel.com> Organization: Red Hat Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5 (3.28.5-1.fc28) Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2018-09-17 at 21:16 +0300, Ville Syrjälä wrote: > On Mon, Sep 17, 2018 at 02:10:02PM -0400, Lyude Paul wrote: > > On Mon, 2018-09-17 at 20:55 +0300, Ville Syrjälä wrote: > > > On Mon, Sep 17, 2018 at 01:43:44PM -0400, Lyude Paul wrote: > > > > Userspace asked them to be forced off, so why would we care about what a > > > > probe tells us? > > > > > > I believe there should be force checks in the callers already. > > > Or are we missing some? > > > > JFYI, what triggered me to send this patch are these error messages that > > come > > from nouveau when a hotplug happens on a port that we've forced off: > > > > [ 1903.918104] nouveau 0000:01:00.0: DRM: DDC responded, but no EDID for DP- > > 2 > > [ 1903.918123] [drm:drm_helper_hpd_irq_event [drm_kms_helper]] > > [CONNECTOR:61:DP-2] status updated from disconnected to disconnected > > > > That being said; I'm sure there are probably some checks missing, but I > > don't > > really see the purpose in calling the driver's probe functions at all if > > they're > > just supposed to return the status we forced. > > Digging through my cobweb ridden local git repository I found this: > > commit bbd17813a7c7d0210c619365707044d0fb29e3f0 > Author: Ville Syrjälä > Date: Mon Jun 10 15:28:55 2013 +0300 > > drm: Ignore forced connectors in drm_helper_hpd_irq_event() > > drm_helper_hpd_irq_event() calls the connector's .detect() function > even for forced connectors. If the returned status doesn't match the > forced status, we will send the hotplug event, causing userspace to > re-probe all the connectors. Eventually we should end up back where > we started when drm_helper_probe_single_connector_modes() overwrites > the connector status with the forced status. > > We can avoid all that pointles work if we just skip forced connectors > in drm_helper_hpd_irq_event(). > > Signed-off-by: Ville Syrjälä > > diff --git a/drivers/gpu/drm/drm_crtc_helper.c > b/drivers/gpu/drm/drm_crtc_helper.c > index ed1334e27c33..4fc2ad76c107 100644 > --- a/drivers/gpu/drm/drm_crtc_helper.c > +++ b/drivers/gpu/drm/drm_crtc_helper.c > @@ -1086,6 +1086,10 @@ void drm_helper_hpd_irq_event(struct drm_device *dev) > mutex_lock(&dev->mode_config.mutex); > list_for_each_entry(connector, &dev->mode_config.connector_list, head) { > > + /* Ignore forced connectors. */ > + if (connector->force) > + continue; > + > /* Only handle HPD capable connectors. */ > if (!(connector->polled & DRM_CONNECTOR_POLL_HPD)) > continue; > > > I guess I never sent it out. Ahhh, to be honest though this patch isn't really enough. drm_helper_hpd_irq_event() isn't going to be used by all drivers (I may remove some usage of it in nouveau in the near future, even) so I still think it would be a better idea to just add this into drm_helper_probe_detect() and drm_helper_probe_detect_ctx() so everything gets covered >