From patchwork Tue Oct 21 10:52:24 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dheeraj Jamwal X-Patchwork-Id: 5119181 Return-Path: X-Original-To: patchwork-ltsi-dev@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 8B2F59F349 for ; Tue, 21 Oct 2014 11:47:19 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id AB35F2010F for ; Tue, 21 Oct 2014 11:47:18 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B082420108 for ; Tue, 21 Oct 2014 11:47:17 +0000 (UTC) Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id A5A7310F4; Tue, 21 Oct 2014 11:08:45 +0000 (UTC) X-Original-To: ltsi-dev@lists.linuxfoundation.org Delivered-To: ltsi-dev@mail.linuxfoundation.org Received: from smtp2.linuxfoundation.org (smtp2.linux-foundation.org [172.17.192.36]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 69C7C10E3 for ; Tue, 21 Oct 2014 11:08:40 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by smtp2.linuxfoundation.org (Postfix) with ESMTP id 0E7111DD16 for ; Tue, 21 Oct 2014 11:08:40 +0000 (UTC) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga101.fm.intel.com with ESMTP; 21 Oct 2014 04:07:38 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,761,1406617200"; d="scan'208";a="617797090" Received: from ubuntu-desktop.png.intel.com ([10.221.122.25]) by fmsmga002.fm.intel.com with ESMTP; 21 Oct 2014 04:07:37 -0700 From: Dheeraj Jamwal To: ltsi-dev@lists.linuxfoundation.org Date: Tue, 21 Oct 2014 18:52:24 +0800 Message-Id: <1413889294-31328-545-git-send-email-dheerajx.s.jamwal@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1413889294-31328-1-git-send-email-dheerajx.s.jamwal@intel.com> References: <1413889294-31328-1-git-send-email-dheerajx.s.jamwal@intel.com> X-Spam-Status: No, score=-5.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org Subject: [LTSI-dev] [PATCH 0544/1094] drm/crtc-helper: don't disable disconnected outputs X-BeenThere: ltsi-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: "A list to discuss patches, development, and other things related to the LTSI project" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: ltsi-dev-bounces@lists.linuxfoundation.org Errors-To: ltsi-dev-bounces@lists.linuxfoundation.org X-Virus-Scanned: ClamAV using ClamSMTP From: Daniel Vetter This is the equivalent change in the crtc helpers as done to the i915 modeset infrastructure in commit b0a2658acb5bf9ca86b4aab011b7106de3af0add Author: Daniel Vetter Date: Tue Dec 18 09:37:54 2012 +0100 drm/i915: don't disable disconnected outputs This was originally introduced to make encoder sharing on radone easier for userspace, but: - It is policy and as such belongs into userspace. E.g. personally I'm fairly annoyed that a flaky cable results in permanent changes of the desktop layout, so I'll kick out DEs which do this. Worse if the kernel also tries to be clever. - It's inconsistent: We only kill disconnected outputs on setCrtc (which userspace might also call when just changing the framebuffer), but not when e.g. we receive a hpd event or in the output poll worker. - It's unexpected behaviour for the userspace driver, at least in the intel ddx we've had tons of bugs where the driver fell over and killed the X session becuase pageflips/vblanks suddenly stopped working. We've had to fix this by wrapping every single setCrtc int a big "recover kms state from the kernel again" operation. - It's suprising for the kernel, too: It took a few mails between Rob, Matt and me for them to notice that little dragon wreaking havoc with the universal plane framebuffer refcounting. - Userspace can cope with it and e.g. Gnome already kills disconnected outputs and reconfigures the desktop automatically. And since there have been no regression reports for the i915 change from over 1 year ago I think all other DEs are also ready. Note that the lines removed in this patch go back to commit a3a0544b2c84e1d7a2022b558ecf66d8c6a8dd93 Author: Dave Airlie Date: Mon Aug 31 15:16:30 2009 +1000 drm/kms: add explicit encoder disable function and detach harder. Unfortunately the patch itself doesn't explain a hole lot about why it was added ... Cc: Matt Roper Cc: Rob Clark Cc: Dave Airlie Cc: Alex Deucher Signed-off-by: Daniel Vetter Signed-off-by: Dave Airlie (cherry picked from commit e3d6ddb35f6221859b6054879d186e13a3af351e) Signed-off-by: Dheeraj Jamwal --- drivers/gpu/drm/drm_crtc_helper.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c index 8823222..eaff755 100644 --- a/drivers/gpu/drm/drm_crtc_helper.c +++ b/drivers/gpu/drm/drm_crtc_helper.c @@ -148,8 +148,6 @@ static void __drm_helper_disable_unused_functions(struct drm_device *dev) list_for_each_entry(connector, &dev->mode_config.connector_list, head) { if (!connector->encoder) continue; - if (connector->status == connector_status_disconnected) - connector->encoder = NULL; } list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {