Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753088AbdHDNqN (ORCPT ); Fri, 4 Aug 2017 09:46:13 -0400 Received: from galahad.ideasonboard.com ([185.26.127.97]:58880 "EHLO galahad.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753063AbdHDNqL (ORCPT ); Fri, 4 Aug 2017 09:46:11 -0400 From: Laurent Pinchart To: Eric Anholt Cc: dri-devel@lists.freedesktop.org, Archit Taneja , Andrzej Hajda , Thierry Reding , linux-kernel@vger.kernel.org, Daniel Vetter Subject: Re: [PATCH v5 2/6] drm/bridge: Add a devm_ allocator for panel bridge. Date: Fri, 04 Aug 2017 16:46:24 +0300 Message-ID: <2023170.2CE3xBA9bq@avalon> User-Agent: KMail/4.14.10 (Linux/4.9.34-gentoo; KDE/4.14.32; x86_64; ; ) In-Reply-To: <20170718210510.12229-2-eric@anholt.net> References: <20170718210510.12229-1-eric@anholt.net> <20170718210510.12229-2-eric@anholt.net> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2665 Lines: 83 Hi Eric, (CC'ing Daniel) Thank you for the patch. On Tuesday 18 Jul 2017 14:05:06 Eric Anholt wrote: > This will let drivers reduce the error cleanup they need, in > particular the "is_panel_bridge" flag. > > v2: Slight cleanup of remove function by Andrzej I just want to point out that, in the context of Daniel's work on hot-unplug, 90% of the devm_* allocations are wrong and will get in the way. All DRM core objects that are accessible one way or another from userspace will need to be properly reference-counted and freed only when the last reference disappears, which could be well after the corresponding device is removed. I believe this could be one such objects :-/ > Signed-off-by: Eric Anholt > Reviewed-by: Andrzej Hajda > --- > drivers/gpu/drm/bridge/panel.c | 30 ++++++++++++++++++++++++++++++ > include/drm/drm_bridge.h | 3 +++ > 2 files changed, 33 insertions(+) > > diff --git a/drivers/gpu/drm/bridge/panel.c b/drivers/gpu/drm/bridge/panel.c > index 685c1a480201..292ee92a9c97 100644 > --- a/drivers/gpu/drm/bridge/panel.c > +++ b/drivers/gpu/drm/bridge/panel.c > @@ -195,3 +195,33 @@ void drm_panel_bridge_remove(struct drm_bridge *bridge) > devm_kfree(panel_bridge->panel->dev, bridge); > } > EXPORT_SYMBOL(drm_panel_bridge_remove); > + > +static void devm_drm_panel_bridge_release(struct device *dev, void *res) > +{ > + struct drm_bridge **bridge = res; > + > + drm_panel_bridge_remove(*bridge); > +} > + > +struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev, > + struct drm_panel *panel, > + u32 connector_type) > +{ > + struct drm_bridge **ptr, *bridge; > + > + ptr = devres_alloc(devm_drm_panel_bridge_release, sizeof(*ptr), > + GFP_KERNEL); > + if (!ptr) > + return ERR_PTR(-ENOMEM); > + > + bridge = drm_panel_bridge_add(panel, connector_type); > + if (!IS_ERR(bridge)) { > + *ptr = bridge; > + devres_add(dev, ptr); > + } else { > + devres_free(ptr); > + } > + > + return bridge; > +} > +EXPORT_SYMBOL(devm_drm_panel_bridge_add); > diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h > index 1dc94d5392e2..6522d4cbc9d9 100644 > --- a/include/drm/drm_bridge.h > +++ b/include/drm/drm_bridge.h > @@ -268,6 +268,9 @@ void drm_bridge_enable(struct drm_bridge *bridge); > struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel, > u32 connector_type); > void drm_panel_bridge_remove(struct drm_bridge *bridge); > +struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev, > + struct drm_panel *panel, > + u32 connector_type); > #endif > > #endif -- Regards, Laurent Pinchart