From patchwork Thu Sep 14 10:19:02 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Ma=C3=ADra_Canal?= X-Patchwork-Id: 13384992 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 0308AEDE9A1 for ; Thu, 14 Sep 2023 10:49:51 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2D71310E262; Thu, 14 Sep 2023 10:49:50 +0000 (UTC) X-Greylist: delayed 1744 seconds by postgrey-1.36 at gabe; Thu, 14 Sep 2023 10:49:47 UTC Received: from fanzine2.igalia.com (fanzine.igalia.com [178.60.130.6]) by gabe.freedesktop.org (Postfix) with ESMTPS id 807B310E262 for ; Thu, 14 Sep 2023 10:49:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:Content-Type:MIME-Version:Message-ID: Date:Subject:Cc:To:From:Sender:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: In-Reply-To:References:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=7xrk9agHZXIsMQu7lfcBnZM62uO342/LylrKQ86z6zY=; b=dWX7CIQU61Bjsx9xqg0M0AQZrb pX1efUVK0R2wNMSWguDKpjek5EjJ980rzUNT8OSzKQVqMJfIiTAgeUnPXfIbBQF4XFABdvRVG4dls bnH35IQD94+l4KTNoESg9sOZhxKcduqxEWjTV0nvSeT6qaYOls4wdTzdVlUVs7iYDqc/GCMTi9nYV qz+LXaNtv5PRN9O6shguYmi255eh4qcorUChK8p4d81dBepTEwdVvZOKVJWmnpydVesMcWXitVc0P PeFdr+Hao7cZQC3+eBvJPQP67uBwpnJpfXBsjTGvKBMKnBWy5oZt/qtNu+PjWxNLgQvR/DexSbEWS jkBHTp5A==; Received: from [177.34.168.16] (helo=morissey..) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1qgjSe-003qXh-PR; Thu, 14 Sep 2023 12:20:37 +0200 From: =?utf-8?q?Ma=C3=ADra_Canal?= To: Rodrigo Siqueira , Melissa Wen , Haneen Mohammed , Arthur Grillo , Daniel Vetter , David Airlie Subject: [PATCH] Revert "drm/vkms: Fix race-condition between the hrtimer and the atomic commit" Date: Thu, 14 Sep 2023 07:19:02 -0300 Message-ID: <20230914102024.1789154-1-mcanal@igalia.com> X-Mailer: git-send-email 2.41.0 MIME-Version: 1.0 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: Daniel Vetter , =?utf-8?q?Ma=C3=ADra_Canal?= , dri-devel@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" This reverts commit a0e6a017ab56936c0405fe914a793b241ed25ee0. Unlocking a mutex in the context of a hrtimer callback is violating mutex locking rules, as mutex_unlock() from interrupt context is not permitted. Links: https://lore.kernel.org/dri-devel/ZQLAc%2FFwkv%2FGiVoK@phenom.ffwll.local/T/#t Acked-by: Daniel Vetter Signed-off-by: Maíra Canal --- drivers/gpu/drm/vkms/vkms_composer.c | 9 ++------- drivers/gpu/drm/vkms/vkms_crtc.c | 9 ++++----- drivers/gpu/drm/vkms/vkms_drv.h | 4 +--- 3 files changed, 7 insertions(+), 15 deletions(-) -- 2.41.0 diff --git a/drivers/gpu/drm/vkms/vkms_composer.c b/drivers/gpu/drm/vkms/vkms_composer.c index d5d4f642d367..3c99fb8b54e2 100644 --- a/drivers/gpu/drm/vkms/vkms_composer.c +++ b/drivers/gpu/drm/vkms/vkms_composer.c @@ -408,15 +408,10 @@ void vkms_set_composer(struct vkms_output *out, bool enabled) if (enabled) drm_crtc_vblank_get(&out->crtc); - mutex_lock(&out->enabled_lock); + spin_lock_irq(&out->lock); old_enabled = out->composer_enabled; out->composer_enabled = enabled; - - /* the composition wasn't enabled, so unlock the lock to make sure the lock - * will be balanced even if we have a failed commit - */ - if (!out->composer_enabled) - mutex_unlock(&out->enabled_lock); + spin_unlock_irq(&out->lock); if (old_enabled) drm_crtc_vblank_put(&out->crtc); diff --git a/drivers/gpu/drm/vkms/vkms_crtc.c b/drivers/gpu/drm/vkms/vkms_crtc.c index 3c5ebf106b66..61e500b8c9da 100644 --- a/drivers/gpu/drm/vkms/vkms_crtc.c +++ b/drivers/gpu/drm/vkms/vkms_crtc.c @@ -16,7 +16,7 @@ static enum hrtimer_restart vkms_vblank_simulate(struct hrtimer *timer) struct drm_crtc *crtc = &output->crtc; struct vkms_crtc_state *state; u64 ret_overrun; - bool ret, fence_cookie, composer_enabled; + bool ret, fence_cookie; fence_cookie = dma_fence_begin_signalling(); @@ -25,15 +25,15 @@ static enum hrtimer_restart vkms_vblank_simulate(struct hrtimer *timer) if (ret_overrun != 1) pr_warn("%s: vblank timer overrun\n", __func__); + spin_lock(&output->lock); ret = drm_crtc_handle_vblank(crtc); if (!ret) DRM_ERROR("vkms failure on handling vblank"); state = output->composer_state; - composer_enabled = output->composer_enabled; - mutex_unlock(&output->enabled_lock); + spin_unlock(&output->lock); - if (state && composer_enabled) { + if (state && output->composer_enabled) { u64 frame = drm_crtc_accurate_vblank_count(crtc); /* update frame_start only if a queued vkms_composer_worker() @@ -295,7 +295,6 @@ int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc, spin_lock_init(&vkms_out->lock); spin_lock_init(&vkms_out->composer_lock); - mutex_init(&vkms_out->enabled_lock); vkms_out->composer_workq = alloc_ordered_workqueue("vkms_composer", 0); if (!vkms_out->composer_workq) diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h index c7ae6c2ba1df..8f5710debb1e 100644 --- a/drivers/gpu/drm/vkms/vkms_drv.h +++ b/drivers/gpu/drm/vkms/vkms_drv.h @@ -108,10 +108,8 @@ struct vkms_output { struct workqueue_struct *composer_workq; /* protects concurrent access to composer */ spinlock_t lock; - /* guarantees that if the composer is enabled, a job will be queued */ - struct mutex enabled_lock; - /* protected by @enabled_lock */ + /* protected by @lock */ bool composer_enabled; struct vkms_crtc_state *composer_state;