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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT 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 D30B9C43381 for ; Thu, 28 Feb 2019 14:03:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A1E7320C01 for ; Thu, 28 Feb 2019 14:03:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732128AbfB1ODq (ORCPT ); Thu, 28 Feb 2019 09:03:46 -0500 Received: from mga12.intel.com ([192.55.52.136]:59011 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727960AbfB1ODp (ORCPT ); Thu, 28 Feb 2019 09:03:45 -0500 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 fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 Feb 2019 06:03:45 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,423,1544515200"; d="scan'208";a="137001786" Received: from stinkbox.fi.intel.com (HELO stinkbox) ([10.237.72.174]) by FMSMGA003.fm.intel.com with SMTP; 28 Feb 2019 06:03:42 -0800 Received: by stinkbox (sSMTP sendmail emulation); Thu, 28 Feb 2019 16:03:41 +0200 Date: Thu, 28 Feb 2019 16:03:41 +0200 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Shayenne Moura , Rodrigo Siqueira , Haneen Mohammed , David Airlie , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] drm/vkms: Solve bug on kms_crc_cursor tests Message-ID: <20190228140341.GG20097@intel.com> References: <20190225142606.gov32asdq3qe375q@smtp.gmail.com> <20190228101107.GL2665@phenom.ffwll.local> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20190228101107.GL2665@phenom.ffwll.local> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 28, 2019 at 11:11:07AM +0100, Daniel Vetter wrote: > On Mon, Feb 25, 2019 at 11:26:06AM -0300, Shayenne Moura wrote: > > vkms_crc_work_handle needs the value of the actual frame to > > schedule the workqueue that calls periodically the vblank > > handler and the destroy state functions. However, the frame > > value returned from vkms_vblank_simulate is updated and > > diminished in vblank_get_timestamp because it is not in a > > vblank interrupt, and return an inaccurate value. > > > > Solve this getting the actual vblank frame directly from the > > vblank->count inside the `struct drm_crtc`, instead of using > > the `drm_accurate_vblank_count` function. > > > > Signed-off-by: Shayenne Moura > > Sorry for the delay, I'm a bit swamped right now :-/ > > Debug work you're doing here is really impressive! But I have no idea > what's going on. It doesn't look like it's just papering over a bug (like > the in_vblank_irq check we've discussed on irc), but I also have no idea > why it works. > > I'll pull in Ville, he understands this better than me. It's not entirely clear what we're trying to fix. From what I can see the crc work seems to be in no way synchronized with page flips, so I'm not sure how all this is really supposed to work. > -Daniel > > > --- > > drivers/gpu/drm/vkms/vkms_crc.c | 4 +++- > > drivers/gpu/drm/vkms/vkms_crtc.c | 4 +++- > > 2 files changed, 6 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/gpu/drm/vkms/vkms_crc.c b/drivers/gpu/drm/vkms/vkms_crc.c > > index d7b409a3c0f8..09a8b00ef1f1 100644 > > --- a/drivers/gpu/drm/vkms/vkms_crc.c > > +++ b/drivers/gpu/drm/vkms/vkms_crc.c > > @@ -161,6 +161,8 @@ void vkms_crc_work_handle(struct work_struct *work) > > struct vkms_output *out = drm_crtc_to_vkms_output(crtc); > > struct vkms_device *vdev = container_of(out, struct vkms_device, > > output); > > + unsigned int pipe = drm_crtc_index(crtc); > > + struct drm_vblank_crtc *vblank = &crtc->dev->vblank[pipe]; > > struct vkms_crc_data *primary_crc = NULL; > > struct vkms_crc_data *cursor_crc = NULL; > > struct drm_plane *plane; > > @@ -196,7 +198,7 @@ void vkms_crc_work_handle(struct work_struct *work) > > if (primary_crc) > > crc32 = _vkms_get_crc(primary_crc, cursor_crc); > > > > - frame_end = drm_crtc_accurate_vblank_count(crtc); > > + frame_end = vblank->count; > > > > /* queue_work can fail to schedule crc_work; add crc for > > * missing frames > > diff --git a/drivers/gpu/drm/vkms/vkms_crtc.c b/drivers/gpu/drm/vkms/vkms_crtc.c > > index 8a9aeb0a9ea8..9bf3268e2e92 100644 > > --- a/drivers/gpu/drm/vkms/vkms_crtc.c > > +++ b/drivers/gpu/drm/vkms/vkms_crtc.c > > @@ -10,6 +10,8 @@ static enum hrtimer_restart vkms_vblank_simulate(struct hrtimer *timer) > > vblank_hrtimer); > > struct drm_crtc *crtc = &output->crtc; > > struct vkms_crtc_state *state = to_vkms_crtc_state(crtc->state); > > + unsigned int pipe = drm_crtc_index(crtc); > > + struct drm_vblank_crtc *vblank = &crtc->dev->vblank[pipe]; > > u64 ret_overrun; > > bool ret; > > > > @@ -20,7 +22,7 @@ static enum hrtimer_restart vkms_vblank_simulate(struct hrtimer *timer) > > DRM_ERROR("vkms failure on handling vblank"); > > > > if (state && output->crc_enabled) { > > - u64 frame = drm_crtc_accurate_vblank_count(crtc); > > + u64 frame = vblank->count; > > > > /* update frame_start only if a queued vkms_crc_work_handle() > > * has read the data > > -- > > 2.17.1 > > > > -- > Daniel Vetter > Software Engineer, Intel Corporation > http://blog.ffwll.ch > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel -- Ville Syrjälä Intel