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=-7.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,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 9A98AC43441 for ; Thu, 29 Nov 2018 08:57:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5D63E2082F for ; Thu, 29 Nov 2018 08:57:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="NKx1Gz/q" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5D63E2082F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ffwll.ch 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 S1726886AbeK2UBp (ORCPT ); Thu, 29 Nov 2018 15:01:45 -0500 Received: from mail-it1-f194.google.com ([209.85.166.194]:53536 "EHLO mail-it1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726579AbeK2UBp (ORCPT ); Thu, 29 Nov 2018 15:01:45 -0500 Received: by mail-it1-f194.google.com with SMTP id g85so2439037ita.3 for ; Thu, 29 Nov 2018 00:57:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=qWmS5X3oWUwyLNW9cMpNUuMHuMWFjeAl5OoIeXLn3BY=; b=NKx1Gz/qnclh1q+jHuyh3xLQoheg9CKQisn6NytxcQzEe1UPev2p9g9s7/zq+JDfD4 7N0IkwiCMMS9bMFxpIjpmmtizqsIK4Os2iR+z9I5FBFXv7WOGSfVZMbVBwdsTUYhi4BW xy49n8LTqPZfZij6ku//3hk2pcKgCz5KRoOak= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=qWmS5X3oWUwyLNW9cMpNUuMHuMWFjeAl5OoIeXLn3BY=; b=AgiwomQw0QbbolTJxGNWYgjHqOmD9/hTy2fi08JQkFtRRxqTd5Abf0e7ZywvWhGyQ+ zMJlrML9rr3S878ZuEnZzGmQiL0kpHznF5yVLCpw9GZmYVlsjW0RhKGrEzpf0FN4oQsq HaOokFeQrUi1Bj0C1yYt6ffEVI7/ugPZR7wro47lEtLzspdE5p+U/gYR3135Zh+kSzWC 4j4QlR52Gm6A4exm6oMOX13lG5vGyz59ZT298rdDObdb69nCWwHi6uRZaBsMxFQKTJRD gqA6fITUv+U5NooztDe3R/lIFwF0pRORAnZIrYTAIqQT0S0HFKwnAAlIqlyasc1O8mjP 8HSw== X-Gm-Message-State: AA+aEWbpmFfJSdRmjiQeKGylDoEOQVAG2H2TL7vCo8bZWpXorjFb+/Ko +1GZdbshanelr1TLvz9+d56+RnjkU4r8bTtFMxQwuQ== X-Google-Smtp-Source: AFSGD/UNTkubjbeVU0TIgrzN47MvpOMCLngt/bD7E4wmZ1cTX+W0oaZf+CQNMYMNc1W4KS1wbgySHnqyzLVHSGkDwnk= X-Received: by 2002:a02:85ae:: with SMTP id d43mr490723jai.70.1543481825119; Thu, 29 Nov 2018 00:57:05 -0800 (PST) MIME-Version: 1.0 References: <3350c5dd5ea08c71e4769ea3801290e7f9238a6c.1541397462.git.sbobroff@linux.ibm.com> <20181129020034.GA10328@tungsten.ozlabs.ibm.com> In-Reply-To: <20181129020034.GA10328@tungsten.ozlabs.ibm.com> From: Daniel Vetter Date: Thu, 29 Nov 2018 09:56:53 +0100 Message-ID: Subject: Re: [PATCH 2/2] drm/ast: Fix connector leak during driver unload To: sbobroff@linux.ibm.com Cc: "airlied@gmail.com" , Dave Airlie , Dave Airlie , Linux Kernel Mailing List , dri-devel Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 29, 2018 at 9:05 AM Sam Bobroff wrote: > > On Thu, Nov 29, 2018 at 09:40:53AM +1000, Dave Airlie wrote: > > On Mon, 5 Nov 2018 at 15:59, Sam Bobroff wrote: > > > > > > When unloading the ast driver, a warning message is printed by > > > drm_mode_config_cleanup() because a reference is still held to one of > > > the drm_connector structs. > > > > > > Correct this by calling drm_framebuffer_remove() in > > > ast_fbdev_destroy(). > > > > > > Signed-off-by: Sam Bobroff > > > --- > > > drivers/gpu/drm/ast/ast_fb.c | 4 ++++ > > > 1 file changed, 4 insertions(+) > > > > > > diff --git a/drivers/gpu/drm/ast/ast_fb.c b/drivers/gpu/drm/ast/ast_fb.c > > > index 0cd827e11fa2..655372ea81e9 100644 > > > --- a/drivers/gpu/drm/ast/ast_fb.c > > > +++ b/drivers/gpu/drm/ast/ast_fb.c > > > @@ -263,6 +263,10 @@ static void ast_fbdev_destroy(struct drm_device *dev, > > > { > > > struct ast_framebuffer *afb = &afbdev->afb; > > > > > > + /* drm_framebuffer_remove() expects us to hold a ref, which it > > > + * will drop, so take one: */ > > > + drm_framebuffer_get(&afb->base); > > > + drm_framebuffer_remove(&afb->base); > > > > This doesn't seem corret, no other driver does this pattern, and I > > can't believe ast is special here. > > > > The get just doesn't make sense. > > Thanks for having a look at this, as I said in the cover letter I was > concerned that it might not be a good fix. > > But the AST driver does seem to be special (or just old?) because it > embeds the drm_framebuffer directly into ast_fbdev and (almost all) > other drivers dynamically allocate and reference count theirs. > > The drm_framebuffer_get() certainly looks weird but it is there in order > to cause drm_framebuffer_remove() to call legacy_remove_fb(), which it > won't do unless the refcount is at least 2. (And because the > drm_framebuffer isn't dynamically allocated in this case we don't really > care about the reference count anyway.) > > An alternative might be to call legacy_remove_fb() directly, but it's > declared static. Do you think it would be better to expose it and call > it directly from the AST driver code? Or is there some other better way > to put the drm_connectors? Your problem isn't the dynamic fb vs. embedded fb for fbdev (you're already using drm_framebuffer_unregister_private to handle that). Your problem is you're not shutting down stuff on driver unload, which means the fb is still in use. drm_atomic_helper_shutdown() takes care of that for atomic drivers. No idea anymore what to do for legacy code, probably need to open code a shutdown sequence. Definitely not the above. -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 2/2] drm/ast: Fix connector leak during driver unload Date: Thu, 29 Nov 2018 09:56:53 +0100 Message-ID: References: <3350c5dd5ea08c71e4769ea3801290e7f9238a6c.1541397462.git.sbobroff@linux.ibm.com> <20181129020034.GA10328@tungsten.ozlabs.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from mail-it1-x142.google.com (mail-it1-x142.google.com [IPv6:2607:f8b0:4864:20::142]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0754E6E4B0 for ; Thu, 29 Nov 2018 08:57:06 +0000 (UTC) Received: by mail-it1-x142.google.com with SMTP id h193so2440970ita.5 for ; Thu, 29 Nov 2018 00:57:05 -0800 (PST) In-Reply-To: <20181129020034.GA10328@tungsten.ozlabs.ibm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: sbobroff@linux.ibm.com Cc: Dave Airlie , Dave Airlie , Linux Kernel Mailing List , dri-devel List-Id: dri-devel@lists.freedesktop.org T24gVGh1LCBOb3YgMjksIDIwMTggYXQgOTowNSBBTSBTYW0gQm9icm9mZiA8c2JvYnJvZmZAbGlu dXguaWJtLmNvbT4gd3JvdGU6Cj4KPiBPbiBUaHUsIE5vdiAyOSwgMjAxOCBhdCAwOTo0MDo1M0FN ICsxMDAwLCBEYXZlIEFpcmxpZSB3cm90ZToKPiA+IE9uIE1vbiwgNSBOb3YgMjAxOCBhdCAxNTo1 OSwgU2FtIEJvYnJvZmYgPHNib2Jyb2ZmQGxpbnV4LmlibS5jb20+IHdyb3RlOgo+ID4gPgo+ID4g PiBXaGVuIHVubG9hZGluZyB0aGUgYXN0IGRyaXZlciwgYSB3YXJuaW5nIG1lc3NhZ2UgaXMgcHJp bnRlZCBieQo+ID4gPiBkcm1fbW9kZV9jb25maWdfY2xlYW51cCgpIGJlY2F1c2UgYSByZWZlcmVu Y2UgaXMgc3RpbGwgaGVsZCB0byBvbmUgb2YKPiA+ID4gdGhlIGRybV9jb25uZWN0b3Igc3RydWN0 cy4KPiA+ID4KPiA+ID4gQ29ycmVjdCB0aGlzIGJ5IGNhbGxpbmcgZHJtX2ZyYW1lYnVmZmVyX3Jl bW92ZSgpIGluCj4gPiA+IGFzdF9mYmRldl9kZXN0cm95KCkuCj4gPiA+Cj4gPiA+IFNpZ25lZC1v ZmYtYnk6IFNhbSBCb2Jyb2ZmIDxzYm9icm9mZkBsaW51eC5pYm0uY29tPgo+ID4gPiAtLS0KPiA+ 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