From patchwork Sun Feb 3 15:41:56 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Noralf_Tr=C3=B8nnes?= X-Patchwork-Id: 10794725 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C076B746 for ; Sun, 3 Feb 2019 15:42:24 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B10092B75F for ; Sun, 3 Feb 2019 15:42:24 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A51512B772; Sun, 3 Feb 2019 15:42:24 +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=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, 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 478142B75F for ; Sun, 3 Feb 2019 15:42:24 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 420716E31A; Sun, 3 Feb 2019 15:42:15 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from smtp.domeneshop.no (smtp.domeneshop.no [IPv6:2a01:5b40:0:3005::1]) by gabe.freedesktop.org (Postfix) with ESMTPS id 3DA406E31A; Sun, 3 Feb 2019 15:42:13 +0000 (UTC) Received: from 211.81-166-168.customer.lyse.net ([81.166.168.211]:41412 helo=localhost.localdomain) by smtp.domeneshop.no with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.84_2) (envelope-from ) id 1gqJuN-0003uZ-CP; Sun, 03 Feb 2019 16:42:11 +0100 From: =?utf-8?q?Noralf_Tr=C3=B8nnes?= To: dri-devel@lists.freedesktop.org Date: Sun, 3 Feb 2019 16:41:56 +0100 Message-Id: <20190203154200.61479-3-noralf@tronnes.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190203154200.61479-1-noralf@tronnes.org> References: <20190203154200.61479-1-noralf@tronnes.org> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 2/6] drm/drv: Prepare to remove drm_dev_unplug() X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: David1.Zhou@amd.com, oleksandr_andrushchenko@epam.com, intel-gfx@lists.freedesktop.org, amd-gfx@lists.freedesktop.org, =?utf-8?q?N?= =?utf-8?q?oralf_Tr=C3=B8nnes?= , alexander.deucher@amd.com, airlied@redhat.com, christian.koenig@amd.com Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP The only thing now that makes drm_dev_unplug() special is that it sets drm_device->unplugged. Move this code to drm_dev_unregister() so that we can remove drm_dev_unplug(). Signed-off-by: Noralf Trønnes Reviewed-by: Oleksandr Andrushchenko Reviewed-by: Daniel Vetter Reviewed-by: Sean Paul --- Maybe s/unplugged/unregistered/ ? I looked at drm_device->registered, but using that would mean that drm_dev_is_unplugged() would return before drm_device is registered. And given that its current purpose is to prevent race against connector registration, I stayed away from it. Noralf. drivers/gpu/drm/drm_drv.c | 27 +++++++++++++++------------ include/drm/drm_drv.h | 10 ++++------ 2 files changed, 19 insertions(+), 18 deletions(-) diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 05bbc2b622fc..e0941200edc6 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -366,15 +366,6 @@ EXPORT_SYMBOL(drm_dev_exit); */ void drm_dev_unplug(struct drm_device *dev) { - /* - * After synchronizing any critical read section is guaranteed to see - * the new value of ->unplugged, and any critical section which might - * still have seen the old value of ->unplugged is guaranteed to have - * finished. - */ - dev->unplugged = true; - synchronize_srcu(&drm_unplug_srcu); - drm_dev_unregister(dev); drm_dev_put(dev); } @@ -832,11 +823,14 @@ EXPORT_SYMBOL(drm_dev_register); * drm_dev_register() but does not deallocate the device. The caller must call * drm_dev_put() to drop their final reference. * - * A special form of unregistering for hotpluggable devices is drm_dev_unplug(), - * which can be called while there are still open users of @dev. + * This function can be called while there are still open users of @dev as long + * as the driver protects its device resources using drm_dev_enter() and + * drm_dev_exit(). * * This should be called first in the device teardown code to make sure - * userspace can't access the device instance any more. + * userspace can't access the device instance any more. Drivers that support + * device unplug will probably want to call drm_atomic_helper_shutdown() first + * in order to disable the hardware on regular driver module unload. */ void drm_dev_unregister(struct drm_device *dev) { @@ -845,6 +839,15 @@ void drm_dev_unregister(struct drm_device *dev) if (drm_core_check_feature(dev, DRIVER_LEGACY)) drm_lastclose(dev); + /* + * After synchronizing any critical read section is guaranteed to see + * the new value of ->unplugged, and any critical section which might + * still have seen the old value of ->unplugged is guaranteed to have + * finished. + */ + dev->unplugged = true; + synchronize_srcu(&drm_unplug_srcu); + dev->registered = false; drm_client_dev_unregister(dev); diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h index ca46a45a9cce..c50696c82a42 100644 --- a/include/drm/drm_drv.h +++ b/include/drm/drm_drv.h @@ -736,13 +736,11 @@ void drm_dev_unplug(struct drm_device *dev); * drm_dev_is_unplugged - is a DRM device unplugged * @dev: DRM device * - * This function can be called to check whether a hotpluggable is unplugged. - * Unplugging itself is singalled through drm_dev_unplug(). If a device is - * unplugged, these two functions guarantee that any store before calling - * drm_dev_unplug() is visible to callers of this function after it completes + * This function can be called to check whether @dev is unregistered. This can + * be used to detect that the underlying parent device is gone. * - * WARNING: This function fundamentally races against drm_dev_unplug(). It is - * recommended that drivers instead use the underlying drm_dev_enter() and + * WARNING: This function fundamentally races against drm_dev_unregister(). It + * is recommended that drivers instead use the underlying drm_dev_enter() and * drm_dev_exit() function pairs. */ static inline bool drm_dev_is_unplugged(struct drm_device *dev)