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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 7EC85C352A3 for ; Tue, 11 Feb 2020 17:13:37 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5A99A20848 for ; Tue, 11 Feb 2020 17:13:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5A99A20848 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id DC47C6E529; Tue, 11 Feb 2020 17:13:36 +0000 (UTC) Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0B00D6E529; Tue, 11 Feb 2020 17:13:36 +0000 (UTC) X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 11 Feb 2020 09:13:35 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,428,1574150400"; d="scan'208";a="280990266" Received: from stinkbox.fi.intel.com (HELO stinkbox) ([10.237.72.174]) by FMSMGA003.fm.intel.com with SMTP; 11 Feb 2020 09:13:32 -0800 Received: by stinkbox (sSMTP sendmail emulation); Tue, 11 Feb 2020 19:13:31 +0200 Date: Tue, 11 Feb 2020 19:13:31 +0200 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Daniel Vetter Message-ID: <20200211171331.GY13686@intel.com> References: <20200211162208.16224-1-ville.syrjala@linux.intel.com> <20200211162208.16224-6-ville.syrjala@linux.intel.com> <20200211170233.GL2363188@phenom.ffwll.local> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200211170233.GL2363188@phenom.ffwll.local> X-Patchwork-Hint: comment User-Agent: Mutt/1.10.1 (2018-07-13) Subject: Re: [Intel-gfx] [PATCH v3 5/7] drm: Validate encoder->possible_clones X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: intel-gfx@lists.freedesktop.org, Thomas Zimmermann , dri-devel@lists.freedesktop.org Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Tue, Feb 11, 2020 at 06:02:33PM +0100, Daniel Vetter wrote: > On Tue, Feb 11, 2020 at 06:22:06PM +0200, Ville Syrjala wrote: > > From: Ville Syrj=E4l=E4 > > = > > Many drivers are populating encoder->possible_clones wrong. Let's > > persuade them to get it right by adding some loud WARNs. > > = > > We'll cross check the bits between any two encoders. So either > > both encoders can clone with the other, or neither can. > > = > > We'll also complain about effectively empty possible_clones, and > > possible_clones containing bits for encoders that don't exist. > > = > > v2: encoder->possible_clones now includes the encoder itelf > > v3: Move to drm_mode_config_validate() (Daniel) > > Document that you get a WARN when this is wrong (Daniel) > > Extract full_encoder_mask() > > = > > Acked-by: Thomas Zimmermann > > Cc: Daniel Vetter > > Signed-off-by: Ville Syrj=E4l=E4 > = > I wonder whether we should start to have some unit tests for stuff like > this, like set up broken driver, make sure we have a WARN in dmesg. But > ideally we'd do that with the mocking stuff Kunit hopefully has soon. > = > > = > = > > --- > > drivers/gpu/drm/drm_mode_config.c | 40 +++++++++++++++++++++++++++++++ > > include/drm/drm_encoder.h | 2 ++ > > 2 files changed, 42 insertions(+) > > = > > diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mo= de_config.c > > index 75e357c7e84d..afc91447293a 100644 > > --- a/drivers/gpu/drm/drm_mode_config.c > > +++ b/drivers/gpu/drm/drm_mode_config.c > > @@ -533,6 +533,17 @@ void drm_mode_config_cleanup(struct drm_device *de= v) > > } > > EXPORT_SYMBOL(drm_mode_config_cleanup); > > = > > +static u32 full_encoder_mask(struct drm_device *dev) > > +{ > > + struct drm_encoder *encoder; > > + u32 encoder_mask =3D 0; > > + > > + drm_for_each_encoder(encoder, dev) > > + encoder_mask |=3D drm_encoder_mask(encoder); > > + > > + return encoder_mask; > > +} > > + > > /* > > * For some reason we want the encoder itself included in > > * possible_clones. Make life easy for drivers by allowing them > > @@ -544,10 +555,39 @@ static void fixup_encoder_possible_clones(struct = drm_encoder *encoder) > > encoder->possible_clones =3D drm_encoder_mask(encoder); > > } > > = > > +static void validate_encoder_possible_clones(struct drm_encoder *encod= er) > > +{ > > + struct drm_device *dev =3D encoder->dev; > > + u32 encoder_mask =3D full_encoder_mask(dev); > > + struct drm_encoder *other; > > + > > + drm_for_each_encoder(other, dev) { > > + WARN(!(encoder->possible_clones & drm_encoder_mask(other)) !=3D > > + !(other->possible_clones & drm_encoder_mask(encoder)), > = > Bikeshed: !! as canonical "make this a bool value" might be slightly > clearer, but whatever. Can repaint. > = > > + "possible_clones mismatch: " > > + "[ENCODER:%d:%s] mask=3D0x%x possible_clones=3D0x%x vs. " > > + "[ENCODER:%d:%s] mask=3D0x%x possible_clones=3D0x%x\n", > > + encoder->base.id, encoder->name, > > + drm_encoder_mask(encoder), encoder->possible_clones, > > + other->base.id, other->name, > > + drm_encoder_mask(other), other->possible_clones); > > + } > > + > > + WARN((encoder->possible_clones & drm_encoder_mask(encoder)) =3D=3D 0 = || > > + (encoder->possible_clones & ~encoder_mask) !=3D 0, > > + "Bogus possible_clones: " > > + "[ENCODER:%d:%s] possible_clones=3D0x%x (full encoder mask=3D0x%= x)\n", > > + encoder->base.id, encoder->name, > > + encoder->possible_clones, encoder_mask); > > +} > = > Since it's next to each another double-checking that the fixup did add the > self-clone is probably too much :-) I changed the fixup to be just if (possible_clones =3D=3D 0) possible_clones =3D drm_encoder_mask(); So if the driver tries to set it up but fails and forgets the encoder itself this WARN will still trip. > = > > + > > void drm_mode_config_validate(struct drm_device *dev) > > { > > struct drm_encoder *encoder; > > = > > drm_for_each_encoder(encoder, dev) > > fixup_encoder_possible_clones(encoder); > > + > > + drm_for_each_encoder(encoder, dev) > > + validate_encoder_possible_clones(encoder); > = > > } > > diff --git a/include/drm/drm_encoder.h b/include/drm/drm_encoder.h > > index 22d6cdf729f1..3741963b9587 100644 > > --- a/include/drm/drm_encoder.h > > +++ b/include/drm/drm_encoder.h > > @@ -163,6 +163,8 @@ struct drm_encoder { > > * any cloning it can leave @possible_clones set to 0. The core will > > * automagically fix this up by setting the bit for the encoder itsel= f. > > * > > + * You will get a WARN if you get this wrong in the driver. > = > Nice. > = > Reviewed-by: Daniel Vetter > = > > + * > > * Note that since encoder objects can't be hotplugged the assigned i= ndices > > * are stable and hence known before registering all objects. > > */ > > -- = > > 2.24.1 > > = > = > -- = > Daniel Vetter > Software Engineer, Intel Corporation > http://blog.ffwll.ch -- = Ville Syrj=E4l=E4 Intel _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx