From mboxrd@z Thu Jan 1 00:00:00 1970 From: daniel@ffwll.ch (Daniel Vetter) Date: Fri, 14 Jun 2013 21:50:22 +0200 Subject: [PATCH RFC 2/8] DRM: Armada: Add Armada DRM driver In-Reply-To: <20130614144251.GN18614@n2100.arm.linux.org.uk> References: <20130612134845.GQ18614@n2100.arm.linux.org.uk> <20130612164914.GT18614@n2100.arm.linux.org.uk> <20130612170512.GU18614@n2100.arm.linux.org.uk> <20130612194021.GX18614@n2100.arm.linux.org.uk> <20130612230057.GY18614@n2100.arm.linux.org.uk> <20130613111903.GA18614@n2100.arm.linux.org.uk> <20130613115016.GB18614@n2100.arm.linux.org.uk> <20130613130339.GD18614@n2100.arm.linux.org.uk> <20130614144251.GN18614@n2100.arm.linux.org.uk> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Jun 14, 2013 at 4:42 PM, Russell King - ARM Linux wrote: > On Fri, Jun 14, 2013 at 04:23:22PM +0200, Daniel Vetter wrote: >> On Thu, Jun 13, 2013 at 3:03 PM, Russell King - ARM Linux >> wrote: >> > There's a bigger issue here - if it's possible for drm_crtc_helper_set_config() >> > to be called with set->fb set but set->mode NULL, then we overwrite >> > set->fb to NULL. Again, that results in a lost reference. >> > >> > For the time being, I'm using this patch, which solves my dropped >> > refcount problem, and marks the other possible dropped reference. >> > Either that check needs to be removed or it needs to properly drop >> > the refcount on the fb before 'losing' the reference to it. >> >> Scrap my other mail, I see now where the leaking happens. One of them >> is interface abuse which is now fixed (and i915 has a bunch of BUG_ONs >> to enforce them). The other one is indeed a real case that eluded me >> when I've done the refcountification for drm_framebuffers. I'll hack >> up some patches, since this seems to be a good excuse to port some of >> the i915 modeset improvements back to the crtc helpers. > > If you're happy with the patch I supplied, that's probably the minimal fix > which should go to stable kernels (I'm using 3.9 here) - this also counts > as a "user visible bug". It's something I've tripped over which causes > exhausts memory and can prevent the X server from starting up. > > If you want me to package the patch up with a commit message and sign-off.. Your patch doesn't fix drm/i915 (since we don't use the crtc helpers any more). And I don't think it's good to have the refcounting partially in the drm core and partially in drivers. I've also thrown a few more things on top just to port a few of the i915 cleanups to the crtc helper. I'll submit my patches asap (need to test them a bit more first). -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: Re: [PATCH RFC 2/8] DRM: Armada: Add Armada DRM driver Date: Fri, 14 Jun 2013 21:50:22 +0200 Message-ID: References: <20130612134845.GQ18614@n2100.arm.linux.org.uk> <20130612164914.GT18614@n2100.arm.linux.org.uk> <20130612170512.GU18614@n2100.arm.linux.org.uk> <20130612194021.GX18614@n2100.arm.linux.org.uk> <20130612230057.GY18614@n2100.arm.linux.org.uk> <20130613111903.GA18614@n2100.arm.linux.org.uk> <20130613115016.GB18614@n2100.arm.linux.org.uk> <20130613130339.GD18614@n2100.arm.linux.org.uk> <20130614144251.GN18614@n2100.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ie0-f172.google.com (mail-ie0-f172.google.com [209.85.223.172]) by gabe.freedesktop.org (Postfix) with ESMTP id 75C25E5C87 for ; Fri, 14 Jun 2013 12:50:23 -0700 (PDT) Received: by mail-ie0-f172.google.com with SMTP id 16so2268566iea.17 for ; Fri, 14 Jun 2013 12:50:23 -0700 (PDT) In-Reply-To: <20130614144251.GN18614@n2100.arm.linux.org.uk> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org Errors-To: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org To: Russell King - ARM Linux Cc: dri-devel , Jason Cooper , "linux-arm-kernel@lists.infradead.org" , Sebastian Hesselbarth List-Id: dri-devel@lists.freedesktop.org On Fri, Jun 14, 2013 at 4:42 PM, Russell King - ARM Linux wrote: > On Fri, Jun 14, 2013 at 04:23:22PM +0200, Daniel Vetter wrote: >> On Thu, Jun 13, 2013 at 3:03 PM, Russell King - ARM Linux >> wrote: >> > There's a bigger issue here - if it's possible for drm_crtc_helper_set_config() >> > to be called with set->fb set but set->mode NULL, then we overwrite >> > set->fb to NULL. Again, that results in a lost reference. >> > >> > For the time being, I'm using this patch, which solves my dropped >> > refcount problem, and marks the other possible dropped reference. >> > Either that check needs to be removed or it needs to properly drop >> > the refcount on the fb before 'losing' the reference to it. >> >> Scrap my other mail, I see now where the leaking happens. One of them >> is interface abuse which is now fixed (and i915 has a bunch of BUG_ONs >> to enforce them). The other one is indeed a real case that eluded me >> when I've done the refcountification for drm_framebuffers. I'll hack >> up some patches, since this seems to be a good excuse to port some of >> the i915 modeset improvements back to the crtc helpers. > > If you're happy with the patch I supplied, that's probably the minimal fix > which should go to stable kernels (I'm using 3.9 here) - this also counts > as a "user visible bug". It's something I've tripped over which causes > exhausts memory and can prevent the X server from starting up. > > If you want me to package the patch up with a commit message and sign-off.. Your patch doesn't fix drm/i915 (since we don't use the crtc helpers any more). And I don't think it's good to have the refcounting partially in the drm core and partially in drivers. I've also thrown a few more things on top just to port a few of the i915 cleanups to the crtc helper. I'll submit my patches asap (need to test them a bit more first). -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch