From patchwork Tue Oct 21 10:57:57 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Dheeraj Jamwal X-Patchwork-Id: 5122021 Return-Path: X-Original-To: patchwork-ltsi-dev@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 684E3C11AC for ; Tue, 21 Oct 2014 12:05:50 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 64F9220155 for ; Tue, 21 Oct 2014 12:05:49 +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 05F6F20138 for ; Tue, 21 Oct 2014 12:05:48 +0000 (UTC) Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 48BB4141D; Tue, 21 Oct 2014 11:13:55 +0000 (UTC) X-Original-To: ltsi-dev@lists.linuxfoundation.org Delivered-To: ltsi-dev@mail.linuxfoundation.org Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 28BD1B7A for ; Tue, 21 Oct 2014 11:13:53 +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 smtp1.linuxfoundation.org (Postfix) with ESMTP id 9B2661F8A8 for ; Tue, 21 Oct 2014 11:13:52 +0000 (UTC) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga101.fm.intel.com with ESMTP; 21 Oct 2014 04:13:52 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,761,1406617200"; d="scan'208";a="617800722" Received: from ubuntu-desktop.png.intel.com ([10.221.122.25]) by fmsmga002.fm.intel.com with ESMTP; 21 Oct 2014 04:13:51 -0700 From: Dheeraj Jamwal To: ltsi-dev@lists.linuxfoundation.org Date: Tue, 21 Oct 2014 18:57:57 +0800 Message-Id: <1413889294-31328-878-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> MIME-Version: 1.0 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 0877/1094] drm: Simplify fb refcounting rules around ->update_plane 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: , Sender: ltsi-dev-bounces@lists.linuxfoundation.org Errors-To: ltsi-dev-bounces@lists.linuxfoundation.org X-Virus-Scanned: ClamAV using ClamSMTP From: Daniel Vetter The introduction of primary planes has apparently caused a bit of fb refcounting fun for people. That makes it a good time to clean up the arcane rules and slight differences between ->update_plane and ->set_config. The new rules are: - The core holds a reference for both the new and the old fb (if they're non-NULL of course) while calling into the driver through either ->update_plane or ->set_config. - Drivers may not clobber plane->fb if their callback fails. If they do that, they need to store a pointer to the old fb in it again. When calling into the driver plane->fb still points at the current (old) framebuffer. - The core will update the plane->fb pointer on success. Drivers can do that themselves too, but aren't required to any more for the primary plane. - The core will update fb refcounts for the plane->fb pointer, presuming the drivers hold up their end of the bargain. v2: Remove now unused tmpfb (Thierry) v3: Drop broken changes from drm_mode_setplane (Ville). Also polish the commit message a bit. v4: Also fix up the handling of ->disable_plane in drm_plane_force_disable. The issue was that we didn't save plane->fb over the ->disable_plane call. Just paranoia, nothing relies on this. v5: Keep still useful comments about directly calling ->set_config, which I should have done for v4 already. Requested by Matt. Cc: Thierry Reding Cc: Ville Syrjälä Cc: Matt Roper Reviewed-by: Matt Roper Signed-off-by: Daniel Vetter (cherry picked from commit 0fe27f063fcef920a0be93ad5e89d9c8ef5c5858) Signed-off-by: Dheeraj Jamwal --- drivers/gpu/drm/drm_crtc.c | 13 +++++++------ drivers/gpu/drm/drm_plane_helper.c | 10 +--------- 2 files changed, 8 insertions(+), 15 deletions(-) diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index 9c3b1ff..9609d0f 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -1145,16 +1145,17 @@ EXPORT_SYMBOL(drm_plane_cleanup); */ void drm_plane_force_disable(struct drm_plane *plane) { + struct drm_framebuffer *old_fb = plane->fb; int ret; - if (!plane->fb) + if (!old_fb) return; ret = plane->funcs->disable_plane(plane); if (ret) DRM_ERROR("failed to disable plane with busy fb\n"); /* disconnect the plane from the fb and crtc: */ - __drm_framebuffer_unreference(plane->fb); + __drm_framebuffer_unreference(old_fb); plane->fb = NULL; plane->crtc = NULL; } @@ -2187,16 +2188,18 @@ int drm_mode_setplane(struct drm_device *dev, void *data, } drm_modeset_lock_all(dev); + old_fb = plane->fb; ret = plane->funcs->update_plane(plane, crtc, fb, plane_req->crtc_x, plane_req->crtc_y, plane_req->crtc_w, plane_req->crtc_h, plane_req->src_x, plane_req->src_y, plane_req->src_w, plane_req->src_h); if (!ret) { - old_fb = plane->fb; plane->crtc = crtc; plane->fb = fb; fb = NULL; + } else { + old_fb = NULL; } drm_modeset_unlock_all(dev); @@ -2239,9 +2242,7 @@ int drm_mode_set_config_internal(struct drm_mode_set *set) ret = crtc->funcs->set_config(set); if (ret == 0) { crtc->primary->crtc = crtc; - - /* crtc->fb must be updated by ->set_config, enforces this. */ - WARN_ON(fb != crtc->primary->fb); + crtc->primary->fb = fb; } list_for_each_entry(tmp, &crtc->dev->mode_config.crtc_list, head) { diff --git a/drivers/gpu/drm/drm_plane_helper.c b/drivers/gpu/drm/drm_plane_helper.c index e768d35..88cce65 100644 --- a/drivers/gpu/drm/drm_plane_helper.c +++ b/drivers/gpu/drm/drm_plane_helper.c @@ -124,7 +124,6 @@ int drm_primary_helper_update(struct drm_plane *plane, struct drm_crtc *crtc, .y2 = crtc->mode.vdisplay, }; struct drm_connector **connector_list; - struct drm_framebuffer *tmpfb; int num_connectors, ret; if (!crtc->enabled) { @@ -176,21 +175,14 @@ int drm_primary_helper_update(struct drm_plane *plane, struct drm_crtc *crtc, set.num_connectors = num_connectors; /* - * set_config() adjusts crtc->primary->fb; however the DRM setplane - * code that called us expects to handle the framebuffer update and - * reference counting; save and restore the current fb before - * calling it. - * - * N.B., we call set_config() directly here rather than using + * We call set_config() directly here rather than using * drm_mode_set_config_internal. We're reprogramming the same * connectors that were already in use, so we shouldn't need the extra * cross-CRTC fb refcounting to accomodate stealing connectors. * drm_mode_setplane() already handles the basic refcounting for the * framebuffers involved in this operation. */ - tmpfb = plane->fb; ret = crtc->funcs->set_config(&set); - plane->fb = tmpfb; kfree(connector_list); return ret;