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=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 29E1BC433E0 for ; Sat, 30 May 2020 03:23:19 +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 E86C92076B for ; Sat, 30 May 2020 03:23:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="raydNK1a" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E86C92076B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ideasonboard.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 5359B6E9B1; Sat, 30 May 2020 03:23:18 +0000 (UTC) Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by gabe.freedesktop.org (Postfix) with ESMTPS id CC4396E9AE for ; Sat, 30 May 2020 03:23:16 +0000 (UTC) Received: from pendragon.ideasonboard.com (81-175-216-236.bb.dnainternet.fi [81.175.216.236]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 541EF2A3; Sat, 30 May 2020 05:23:14 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1590808994; bh=Zfa2hyUE+8NeAdc6/DlrMkX1P+v+OgrkI7tIOKsks5E=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=raydNK1aLuq4wVNrkxFPd2/4vTWgHS0SaLLBEuCQ+r9XJiz8qpXgwmKaMnQtX2nH2 SwJHb9BT8c1lXAyw2MyHcffDDZ0rSrgqoCr6pjVLg8YiiTNOrtur9llwYcxpAuvI39 iflkBGx4ZNkXL5+YQbKGBABkyzrjn3gwshGMW2FY= Date: Sat, 30 May 2020 06:22:58 +0300 From: Laurent Pinchart To: Daniel Vetter Subject: Re: [PATCH] drm/atomic-helper: reset vblank on crtc reset Message-ID: <20200530032258.GD5961@pendragon.ideasonboard.com> References: <20200527094757.1414174-2-daniel.vetter@ffwll.ch> <20200527095332.1439425-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200527095332.1439425-1-daniel.vetter@ffwll.ch> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Alexandre Belloni , Tetsuo Handa , Liviu Dudau , DRI Development , Thierry Reding , Daniel Vetter , Mihail Atanassov , Sam Ravnborg , Emil Velikov , Jonathan Hunter , David Airlie , Ludovic Desroches , Tomi Valkeinen , "James \(Qian\) Wang" , syzbot+0871b14ca2e2fb64f6e3@syzkaller.appspotmail.com, Intel Graphics Development , Jyri Sarha , Sean Paul , linux-tegra@vger.kernel.org, Thomas Gleixner , Boris Brezillon , Nicolas Ferre , zhengbin , Thomas Zimmermann , Brian Masney Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi Daniel, Thank you for the patch. On Wed, May 27, 2020 at 11:53:32AM +0200, Daniel Vetter wrote: > Only when vblanks are supported ofc. > > Some drivers do this already, but most unfortunately missed it. This > opens up bugs after driver load, before the crtc is enabled for the > first time. syzbot spotted this when loading vkms as a secondary > output. Given how many drivers are buggy it's best to solve this once > and for all in shared helper code. > > Aside from moving the few existing calls to drm_crtc_vblank_reset into > helpers (i915 doesn't use helpers, so keeps its own) I think the > regression risk is minimal: atomic helpers already rely on drivers > calling drm_crtc_vblank_on/off correctly in their hooks when they > support vblanks. And driver that's failing to handle vblanks after > this is missing those calls already, and vblanks could only work by > accident when enabling a CRTC for the first time right after boot. > > Big thanks to Tetsuo for helping track down what's going wrong here. > > There's only a few drivers which already had the necessary call and > needed some updating: > - komeda, atmel and tidss also needed to be changed to call > __drm_atomic_helper_crtc_reset() intead of open coding it > - tegra and msm even had it in the same place already, just code > motion, and malidp already uses __drm_atomic_helper_crtc_reset(). Have you intentionally not touched drivers that use drm_crtc_vblank_off() at init time instead of drm_crtc_vblank_reset() ? I'm thinking about omapdrm and rcar-du that both call neither drm_crtc_vblank_reset() nor __drm_atomic_helper_crtc_reset() in their CRTC reset handler, and call drm_crtc_vblank_off() at init time. Should these (and likely other) drivers be updated ? Other than that the patch looks good to me, Reviewed-by: Laurent Pinchart > Only call left is in i915, which doesn't use drm_mode_config_reset, > but has its own fastboot infrastructure. So that's the only case where > we actually want this in the driver still. > > I've also reviewed all other drivers which set up vblank support with > drm_vblank_init. After the previous patch fixing mxsfb all atomic > drivers do call drm_crtc_vblank_on/off as they should, the remaining > drivers are either legacy kms or legacy dri1 drivers, so not affected > by this change to atomic helpers. > > v2: Use the drm_dev_has_vblank() helper. > > Link: https://syzkaller.appspot.com/bug?id=0ba17d70d062b2595e1f061231474800f076c7cb > Reported-by: Tetsuo Handa > Reported-by: syzbot+0871b14ca2e2fb64f6e3@syzkaller.appspotmail.com > Cc: Tetsuo Handa > Cc: "James (Qian) Wang" > Cc: Liviu Dudau > Cc: Mihail Atanassov > Cc: Brian Starkey > Cc: Sam Ravnborg > Cc: Boris Brezillon > Cc: Nicolas Ferre > Cc: Alexandre Belloni > Cc: Ludovic Desroches > Cc: Maarten Lankhorst > Cc: Maxime Ripard > Cc: Thomas Zimmermann > Cc: David Airlie > Cc: Daniel Vetter > Cc: Thierry Reding > Cc: Jonathan Hunter > Cc: Jyri Sarha > Cc: Tomi Valkeinen > Cc: Rob Clark > Cc: Sean Paul > Cc: Brian Masney > Cc: Emil Velikov > Cc: zhengbin > Cc: Thomas Gleixner > Cc: linux-tegra@vger.kernel.org > Signed-off-by: Daniel Vetter > --- > drivers/gpu/drm/arm/display/komeda/komeda_crtc.c | 7 ++----- > drivers/gpu/drm/arm/malidp_drv.c | 1 - > drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c | 7 ++----- > drivers/gpu/drm/drm_atomic_state_helper.c | 4 ++++ > drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c | 2 -- > drivers/gpu/drm/tegra/dc.c | 1 - > drivers/gpu/drm/tidss/tidss_crtc.c | 3 +-- > drivers/gpu/drm/tidss/tidss_kms.c | 4 ---- > 8 files changed, 9 insertions(+), 20 deletions(-) > > diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c > index 56bd938961ee..f33418d6e1a0 100644 > --- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c > +++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c > @@ -492,10 +492,8 @@ static void komeda_crtc_reset(struct drm_crtc *crtc) > crtc->state = NULL; > > state = kzalloc(sizeof(*state), GFP_KERNEL); > - if (state) { > - crtc->state = &state->base; > - crtc->state->crtc = crtc; > - } > + if (state) > + __drm_atomic_helper_crtc_reset(crtc, &state->base); > } > > static struct drm_crtc_state * > @@ -616,7 +614,6 @@ static int komeda_crtc_add(struct komeda_kms_dev *kms, > return err; > > drm_crtc_helper_add(crtc, &komeda_crtc_helper_funcs); > - drm_crtc_vblank_reset(crtc); > > crtc->port = kcrtc->master->of_output_port; > > diff --git a/drivers/gpu/drm/arm/malidp_drv.c b/drivers/gpu/drm/arm/malidp_drv.c > index c2507b7d8512..02904392e370 100644 > --- a/drivers/gpu/drm/arm/malidp_drv.c > +++ b/drivers/gpu/drm/arm/malidp_drv.c > @@ -870,7 +870,6 @@ static int malidp_bind(struct device *dev) > drm->irq_enabled = true; > > ret = drm_vblank_init(drm, drm->mode_config.num_crtc); > - drm_crtc_vblank_reset(&malidp->crtc); > if (ret < 0) { > DRM_ERROR("failed to initialise vblank\n"); > goto vblank_fail; > diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c > index 10985134ce0b..ce246b96330b 100644 > --- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c > +++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c > @@ -411,10 +411,8 @@ static void atmel_hlcdc_crtc_reset(struct drm_crtc *crtc) > } > > state = kzalloc(sizeof(*state), GFP_KERNEL); > - if (state) { > - crtc->state = &state->base; > - crtc->state->crtc = crtc; > - } > + if (state) > + __drm_atomic_helper_crtc_reset(crtc, &state->base); > } > > static struct drm_crtc_state * > @@ -528,7 +526,6 @@ int atmel_hlcdc_crtc_create(struct drm_device *dev) > } > > drm_crtc_helper_add(&crtc->base, &lcdc_crtc_helper_funcs); > - drm_crtc_vblank_reset(&crtc->base); > > drm_mode_crtc_set_gamma_size(&crtc->base, ATMEL_HLCDC_CLUT_SIZE); > drm_crtc_enable_color_mgmt(&crtc->base, 0, false, > diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/drm_atomic_state_helper.c > index 8fce6a115dfe..9ad74045158e 100644 > --- a/drivers/gpu/drm/drm_atomic_state_helper.c > +++ b/drivers/gpu/drm/drm_atomic_state_helper.c > @@ -32,6 +32,7 @@ > #include > #include > #include > +#include > #include > > #include > @@ -93,6 +94,9 @@ __drm_atomic_helper_crtc_reset(struct drm_crtc *crtc, > if (crtc_state) > __drm_atomic_helper_crtc_state_reset(crtc_state, crtc); > > + if (drm_dev_has_vblank(crtc->dev)) > + drm_crtc_vblank_reset(crtc); > + > crtc->state = crtc_state; > } > EXPORT_SYMBOL(__drm_atomic_helper_crtc_reset); > diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c > index ca3368c828d0..9606185c284b 100644 > --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c > +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c > @@ -1117,8 +1117,6 @@ static void mdp5_crtc_reset(struct drm_crtc *crtc) > mdp5_crtc_destroy_state(crtc, crtc->state); > > __drm_atomic_helper_crtc_reset(crtc, &mdp5_cstate->base); > - > - drm_crtc_vblank_reset(crtc); > } > > static const struct drm_crtc_funcs mdp5_crtc_funcs = { > diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c > index 83f31c6e891c..9b308b572eac 100644 > --- a/drivers/gpu/drm/tegra/dc.c > +++ b/drivers/gpu/drm/tegra/dc.c > @@ -1168,7 +1168,6 @@ static void tegra_crtc_reset(struct drm_crtc *crtc) > tegra_crtc_atomic_destroy_state(crtc, crtc->state); > > __drm_atomic_helper_crtc_reset(crtc, &state->base); > - drm_crtc_vblank_reset(crtc); > } > > static struct drm_crtc_state * > diff --git a/drivers/gpu/drm/tidss/tidss_crtc.c b/drivers/gpu/drm/tidss/tidss_crtc.c > index 89a226912de8..4d01c4af61cd 100644 > --- a/drivers/gpu/drm/tidss/tidss_crtc.c > +++ b/drivers/gpu/drm/tidss/tidss_crtc.c > @@ -352,8 +352,7 @@ static void tidss_crtc_reset(struct drm_crtc *crtc) > return; > } > > - crtc->state = &tcrtc->base; > - crtc->state->crtc = crtc; > + __drm_atomic_helper_crtc_reset(crtc, &tcrtc->base); > } > > static struct drm_crtc_state *tidss_crtc_duplicate_state(struct drm_crtc *crtc) > diff --git a/drivers/gpu/drm/tidss/tidss_kms.c b/drivers/gpu/drm/tidss/tidss_kms.c > index 4b99e9fa84a5..e6ab59eed259 100644 > --- a/drivers/gpu/drm/tidss/tidss_kms.c > +++ b/drivers/gpu/drm/tidss/tidss_kms.c > @@ -278,10 +278,6 @@ int tidss_modeset_init(struct tidss_device *tidss) > if (ret) > return ret; > > - /* Start with vertical blanking interrupt reporting disabled. */ > - for (i = 0; i < tidss->num_crtcs; ++i) > - drm_crtc_vblank_reset(tidss->crtcs[i]); > - > drm_mode_config_reset(ddev); > > dev_dbg(tidss->dev, "%s done\n", __func__); -- Regards, Laurent Pinchart _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel