Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752396AbdF0OaP (ORCPT ); Tue, 27 Jun 2017 10:30:15 -0400 Received: from mga07.intel.com ([134.134.136.100]:14807 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752198AbdF0OaD (ORCPT ); Tue, 27 Jun 2017 10:30:03 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.39,401,1493708400"; d="scan'208";a="279155090" Subject: Re: [PATCH v2] drm/core: Fail atomic IOCTL with no CRTC state but with signaling. To: Harry Wentland , Andrey Grodzovsky , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, amd-gfx@lists.freedesktop.org, seanpaul@chromium.org References: <0d603149-3fb0-3d48-89e5-77e3f7686415@amd.com> <1497981426-27203-1-git-send-email-Andrey.Grodzovsky@amd.com> <26571917-afb7-fb53-c002-5869cf8ccdf9@amd.com> <20170627073740.wz5xix2ecmvh4rbn@phenom.ffwll.local> From: Maarten Lankhorst Message-ID: <2fa47671-6a2b-5a19-3072-e7f59b92cb4d@linux.intel.com> Date: Tue, 27 Jun 2017 16:29:44 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.1.1 MIME-Version: 1.0 In-Reply-To: <20170627073740.wz5xix2ecmvh4rbn@phenom.ffwll.local> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3710 Lines: 101 Op 27-06-17 om 09:37 schreef Daniel Vetter: > On Mon, Jun 26, 2017 at 03:44:07PM -0400, Harry Wentland wrote: >> On 2017-06-20 01:57 PM, Andrey Grodzovsky wrote: >>> Problem : While running IGT kms_atomic_transition test suite i encountered >>> a hang in drmHandleEvent immediately following an atomic_commit. >>> After dumping the atomic state I relized that in this case there was >>> not even one CRTC attached to the state and only disabled >>> planes. This probably due to a commit which hadn't changed any property >>> which would require attaching crtc state. This means drmHandleEvent >>> will never wake up from read since without CRTC in atomic state >>> the event fd will not be signaled. >>> >>> Fix: Protect against this issue by failing atomic_commit early in >>> drm_mode_atomic_commit where such probelm can be identified. >>> >>> v2: >>> Fix typos and extra newlines. >>> >>> Change-Id: I3ee28ffae35fd1e8bfe553146c44da53da02e6f8 >>> Signed-off-by: Andrey Grodzovsky >> Reviewed-by: Harry Wentland > Stalling on this hoping for the igt patch. Does it exist already? > -Daniel > >> Harry >> >>> --- >>> drivers/gpu/drm/drm_atomic.c | 11 ++++++++++- >>> 1 file changed, 10 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c >>> index a567310..48145bf 100644 >>> --- a/drivers/gpu/drm/drm_atomic.c >>> +++ b/drivers/gpu/drm/drm_atomic.c >>> @@ -1933,7 +1933,7 @@ static int prepare_crtc_signaling(struct drm_device *dev, >>> { >>> struct drm_crtc *crtc; >>> struct drm_crtc_state *crtc_state; >>> - int i, ret; >>> + int i, c = 0, ret; >>> >>> if (arg->flags & DRM_MODE_ATOMIC_TEST_ONLY) >>> return 0; >>> @@ -1994,8 +1994,17 @@ static int prepare_crtc_signaling(struct drm_device *dev, >>> >>> crtc_state->event->base.fence = fence; >>> } >>> + >>> + c++; >>> } >>> >>> + /* >>> + * Having this flag means user mode pends on event which will never >>> + * reach due to lack of at least one CRTC for signaling >>> + */ >>> + if (c == 0 && (arg->flags & DRM_MODE_PAGE_FLIP_EVENT)) >>> + return -EINVAL; >>> + >>> return 0; >>> } >>> >>> Just do it, and I'll commit this to igt? diff --git a/tests/kms_atomic.c b/tests/kms_atomic.c index 6375fede7179..77429b3db384 100644 --- a/tests/kms_atomic.c +++ b/tests/kms_atomic.c @@ -1205,6 +1205,15 @@ static void crtc_invalid_params(struct kms_atomic_crtc_state *crtc_old, crtc_commit_atomic(&crtc, plane, req, ATOMIC_RELAX_NONE, DRM_MODE_ATOMIC_TEST_ONLY); + /* + * TEST_ONLY cannot be combined with DRM_MODE_PAGE_FLIP_EVENT, + * but DRM_MODE_PAGE_FLIP_EVENT will always generate EINVAL + * without valid crtc, so test it here. + */ + crtc_commit_atomic_err(&crtc, plane, req, ATOMIC_RELAX_NONE, + DRM_MODE_ATOMIC_TEST_ONLY | DRM_MODE_PAGE_FLIP_EVENT, + EINVAL); + /* Create a blob which is the wrong size to be a valid mode. */ do_or_die(drmModeCreatePropertyBlob(crtc.state->desc->fd, crtc.mode.data, @@ -1356,12 +1365,12 @@ static void atomic_invalid_params(struct kms_atomic_crtc_state *crtc, /* Valid pointers, but still should copy nothing. */ do_ioctl(desc->fd, DRM_IOCTL_MODE_ATOMIC, &ioc); - /* Nonsense flags. */ - ioc.flags = 0xdeadbeef; + /* Valid noop, but with event set should fail. */ + ioc.flags = DRM_MODE_PAGE_FLIP_EVENT; do_ioctl_err(desc->fd, DRM_IOCTL_MODE_ATOMIC, &ioc, EINVAL); - /* Specifically forbidden combination. */ - ioc.flags = DRM_MODE_ATOMIC_TEST_ONLY | DRM_MODE_PAGE_FLIP_EVENT; + /* Nonsense flags. */ + ioc.flags = 0xdeadbeef; do_ioctl_err(desc->fd, DRM_IOCTL_MODE_ATOMIC, &ioc, EINVAL); ioc.flags = 0;