From patchwork Wed Oct 11 15:20:13 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 9999921 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4DDB6602BF for ; Wed, 11 Oct 2017 15:22:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3688E28A83 for ; Wed, 11 Oct 2017 15:22:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2AF2F28A86; Wed, 11 Oct 2017 15:22:13 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 93E0328A83 for ; Wed, 11 Oct 2017 15:22:12 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D250B6E0D0; Wed, 11 Oct 2017 15:22:11 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mout.kundenserver.de (mout.kundenserver.de [212.227.126.187]) by gabe.freedesktop.org (Postfix) with ESMTPS id 741626E0D0 for ; Wed, 11 Oct 2017 15:22:10 +0000 (UTC) Received: from wuerfel.lan ([95.208.190.237]) by mrelayeu.kundenserver.de (mreue005 [212.227.15.129]) with ESMTPA (Nemesis) id 0LgL5M-1dWUFz3LYy-00nhZz; Wed, 11 Oct 2017 17:21:55 +0200 From: Arnd Bergmann To: Daniel Vetter , Daniel Vetter , Jani Nikula , Sean Paul , David Airlie Subject: [PATCH 2/2] drm: vblank: remove drm_timestamp_monotonic parameter Date: Wed, 11 Oct 2017 17:20:13 +0200 Message-Id: <20171011152059.2394516-2-arnd@arndb.de> X-Mailer: git-send-email 2.9.0 In-Reply-To: <20171011152059.2394516-1-arnd@arndb.de> References: <20171011152059.2394516-1-arnd@arndb.de> X-Provags-ID: V03:K0:+iSiwYr4yjMALO97MSehAUeg6O03hD8h74QYvWT18Nzqap+aA0c 59gcvenpIjoZtupQDFdBhmxyP00yfYB5VfBEP5RiSC6VTCkAAKE6X8DXT+7ZUWD4CwMyiPl Togp+3vhX5GU7tvBmWpx1IUPz2rcrUf4t9A8vDHbeQiEtKp7dxPRh8H5O/o9TLHiTbJQ7tz WhKvSqkWfvaxRciQKxVMA== X-UI-Out-Filterresults: notjunk:1; V01:K0:lCqpw6QlOQg=:XPZrUDPwI0SIVC5RIEwV6n rxM3jikc/1JiR0i7sdvVM9v1NU397xEiS2XGzYMlHhelMlyAT5PIOamwIKf0CbpmO3QJSdqyd QQU+Ln4S3L2/dLfoVJjrA6kndWIPeDG5Bo2+Ck0CsQMNaCGMOFipjomERKDaWcGicSg4LG/nv cIKak+Iz+R4CofaCnwfTn9+UQfy6WlplQba/9xu6daX7+P3btkzMudM72lGn3QMjFLEW6SXH0 FQ+GmUKM5kdyt9r8pRngvI4eTTFJHQt4ahRb2TYojN0wiNlbtNODRvyOdUnl3SoHgJj7DVa8i imHKJQZA/Py5a6vL9fYqmc7gQ1yG6WJ9Rzqp0tvWyXYHHM0zbSEv8KxG+ghI/CtKWkqz/yWAH dsyUZYRFy0EplicMnwrZVFeIyYaqb4aZ00yTd5g2F25Le7pOomePvHuVyEJKRgK7OSICDzA5p FomU/miquHiHp5IARgyIEzUA0dXqnUl0vNLi4kvOw6WA/WGg94cndVRHU+gUl64g+SPeW4g3Z xenmzIlI2kVjd/dtEdYt4UfUOzeZ5a/L0VYBT7AcsEQL1rnabz17w/3YdhwJv6GlpKJHjWgcu MBhjkSa4HfwOfGf1rGFkvL1C7JszK2AG945W5ART0y9OGGJ/KJt9zl5wi05SV5xgtafV9ddnv 8elqr2suQyxxmiU+U6yjqcmEp3KAhWwW796aZlnFe6RrOiE5p4+5Ps9UAsbf1hKtGMAUw2TRX WBcvd7qolRi8kmKDjYAEhhMMoSHk/68mz4MM5w== Cc: Arnd Bergmann , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Alex Deucher , Dave Airlie X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP There is a risk of overflowing vblank timestamps in 2038 or 2106 if someone sets the drm_timestamp_monotonic module parameter to zero. I found no indication of anyone ever setting the parameter, or complaining about the default being wrong, after it was introduced as a way to handle backwards-compatibility with linux prior to c61eef726a78 ("drm: add support for monotonic vblank timestamps"), so it's probably safer to just remove the parameter completely and only allowing the default behavior. Signed-off-by: Arnd Bergmann Acked-by: Daniel Stone --- drivers/gpu/drm/drm_internal.h | 1 - drivers/gpu/drm/drm_ioctl.c | 2 +- drivers/gpu/drm/drm_vblank.c | 29 ++++++----------------------- 3 files changed, 7 insertions(+), 25 deletions(-) diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h index fbc3f308fa19..edd921adcf33 100644 --- a/drivers/gpu/drm/drm_internal.h +++ b/drivers/gpu/drm/drm_internal.h @@ -55,7 +55,6 @@ int drm_clients_info(struct seq_file *m, void* data); int drm_gem_name_info(struct seq_file *m, void *data); /* drm_vblank.c */ -extern unsigned int drm_timestamp_monotonic; void drm_vblank_disable_and_save(struct drm_device *dev, unsigned int pipe); void drm_vblank_cleanup(struct drm_device *dev); diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c index a9ae6dd2d593..a78f03155466 100644 --- a/drivers/gpu/drm/drm_ioctl.c +++ b/drivers/gpu/drm/drm_ioctl.c @@ -235,7 +235,7 @@ static int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_ /* Only some caps make sense with UMS/render-only drivers. */ switch (req->capability) { case DRM_CAP_TIMESTAMP_MONOTONIC: - req->value = drm_timestamp_monotonic; + req->value = 1; return 0; case DRM_CAP_PRIME: req->value |= dev->driver->prime_fd_to_handle ? DRM_PRIME_CAP_IMPORT : 0; diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c index c605c3ad6b6e..810a93fc558b 100644 --- a/drivers/gpu/drm/drm_vblank.c +++ b/drivers/gpu/drm/drm_vblank.c @@ -82,20 +82,12 @@ drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe, static unsigned int drm_timestamp_precision = 20; /* Default to 20 usecs. */ -/* - * Default to use monotonic timestamps for wait-for-vblank and page-flip - * complete events. - */ -unsigned int drm_timestamp_monotonic = 1; - static int drm_vblank_offdelay = 5000; /* Default to 5000 msecs. */ module_param_named(vblankoffdelay, drm_vblank_offdelay, int, 0600); module_param_named(timestamp_precision_usec, drm_timestamp_precision, int, 0600); -module_param_named(timestamp_monotonic, drm_timestamp_monotonic, int, 0600); MODULE_PARM_DESC(vblankoffdelay, "Delay until vblank irq auto-disable [msecs] (0: never disable, <0: disable immediately)"); MODULE_PARM_DESC(timestamp_precision_usec, "Max. error on timestamps [usecs]"); -MODULE_PARM_DESC(timestamp_monotonic, "Use monotonic timestamps"); static void store_vblank(struct drm_device *dev, unsigned int pipe, u32 vblank_count_inc, @@ -672,9 +664,6 @@ bool drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, delta_ns = div_s64(1000000LL * (vpos * mode->crtc_htotal + hpos), mode->crtc_clock); - if (!drm_timestamp_monotonic) - etime = ktime_mono_to_real(etime); - /* save this only for debugging purposes */ ts_etime = ktime_to_timespec64(etime); ts_vblank_time = ktime_to_timespec64(*vblank_time); @@ -694,11 +683,6 @@ bool drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, } EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos); -static ktime_t get_drm_timestamp(void) -{ - return drm_timestamp_monotonic ? ktime_get() : ktime_get_real(); -} - /** * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent * vblank interval @@ -738,7 +722,7 @@ drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe, * Return current monotonic/gettimeofday timestamp as best estimate. */ if (!ret) - *tvblank = get_drm_timestamp(); + *tvblank = ktime_get(); return ret; } @@ -811,8 +795,8 @@ static void send_vblank_event(struct drm_device *dev, e->event.sequence = seq; /* * e->event is a user space structure, with hardcoded unsigned - * 32-bit seconds/microseconds. This will overflow in 2106 for - * drm_timestamp_monotonic==0, but not with drm_timestamp_monotonic==1 + * 32-bit seconds/microseconds. This is safe as we always use + * monotonic timestamps since linux-4.15 */ e->event.tv_sec = tv.tv_sec; e->event.tv_usec = tv.tv_nsec / 1000; @@ -899,7 +883,7 @@ void drm_crtc_send_vblank_event(struct drm_crtc *crtc, } else { seq = 0; - now = get_drm_timestamp(); + now = ktime_get(); } e->pipe = pipe; e->event.crtc_id = crtc->base.id; @@ -1408,9 +1392,8 @@ static void drm_wait_vblank_reply(struct drm_device *dev, unsigned int pipe, /* * drm_wait_vblank_reply is a UAPI structure that uses 'long' - * to store the seconds. This will overflow in y2038 on 32-bit - * architectures with drm_timestamp_monotonic==0, but not with - * drm_timestamp_monotonic==1 (the default). + * to store the seconds. This is safe as we always use monotonic + * timestamps since linux-4.15. */ reply->sequence = drm_vblank_count_and_time(dev, pipe, &now); ts = ktime_to_timespec64(now);