From patchwork Thu Nov 28 11:02:53 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Boris Brezillon X-Patchwork-Id: 13887902 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 821EDD690FC for ; Thu, 28 Nov 2024 11:03:06 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C00AC10E332; Thu, 28 Nov 2024 11:03:03 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=collabora.com header.i=@collabora.com header.b="REy49t4H"; dkim-atps=neutral Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) by gabe.freedesktop.org (Postfix) with ESMTPS id C53F410E330 for ; Thu, 28 Nov 2024 11:03:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1732791779; bh=2fn9pT493HckF03yeT4W2rjx4XTGVkY1S2nWjV/krdk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=REy49t4HD9Qv/9Es5MJ3Jw5bZPGUTwtmtP4VKNe2bE3r8apUHDhB8fEvp5n13h6mi LioXpWF8RwGVo1/yMU1StrEUkOYIK49lx33qtKRBDzu0Kar7ES1MSSUDpWDVi1xwYp nZsggjyWpEnpZD4rvpxVcoX7OydCu3UhyBW9qe/TaQms8YjV+6kYdnNwijg+xnLWAZ 7MNZLI6ByU+yJ4txRJJKAE6StNeY3rAEL1p25HNSUR8auiBNkPWh2Ewck1byzADbrR cn4nWKUSjedOR97xNJjxjKJ/LiepxeKv5KY4cZFuLv0c2TEH9at3jRXteC0y3mc4i+ 6lCVhTgsMfnJg== Received: from localhost.localdomain (unknown [IPv6:2a01:e0a:2c:6930:5cf4:84a1:2763:fe0d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bbrezillon) by bali.collaboradmins.com (Postfix) with ESMTPSA id 50C2517E3620; Thu, 28 Nov 2024 12:02:59 +0100 (CET) From: Boris Brezillon To: Boris Brezillon , Steven Price , Liviu Dudau , =?utf-8?q?Adri=C3=A1n_Larumbe?= Cc: dri-devel@lists.freedesktop.org, kernel@collabora.com Subject: [PATCH v2 4/5] drm/panthor: Be robust against resume failures Date: Thu, 28 Nov 2024 12:02:53 +0100 Message-ID: <20241128110255.3182366-5-boris.brezillon@collabora.com> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241128110255.3182366-1-boris.brezillon@collabora.com> References: <20241128110255.3182366-1-boris.brezillon@collabora.com> 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: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" When the runtime PM resume callback returns an error, it puts the device in a state where it can't be resumed anymore. Make sure we can recover from such transient failures by calling pm_runtime_set_suspended() explicitly after a pm_runtime_resume_and_get() failure. v2: - Add a comment explaining potential races in panthor_device_resume_and_get() Signed-off-by: Boris Brezillon --- drivers/gpu/drm/panthor/panthor_device.c | 1 + drivers/gpu/drm/panthor/panthor_device.h | 26 ++++++++++++++++++++++++ drivers/gpu/drm/panthor/panthor_drv.c | 2 +- drivers/gpu/drm/panthor/panthor_sched.c | 4 ++-- 4 files changed, 30 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/panthor/panthor_device.c b/drivers/gpu/drm/panthor/panthor_device.c index e3b22107b268..0362101ea896 100644 --- a/drivers/gpu/drm/panthor/panthor_device.c +++ b/drivers/gpu/drm/panthor/panthor_device.c @@ -500,6 +500,7 @@ int panthor_device_resume(struct device *dev) err_set_suspended: atomic_set(&ptdev->pm.state, PANTHOR_DEVICE_PM_STATE_SUSPENDED); + atomic_set(&ptdev->pm.recovery_needed, 1); return ret; } diff --git a/drivers/gpu/drm/panthor/panthor_device.h b/drivers/gpu/drm/panthor/panthor_device.h index 0e68f5a70d20..b6c4f25a5d6e 100644 --- a/drivers/gpu/drm/panthor/panthor_device.h +++ b/drivers/gpu/drm/panthor/panthor_device.h @@ -9,6 +9,7 @@ #include #include #include +#include #include #include @@ -180,6 +181,9 @@ struct panthor_device { * is suspended. */ struct page *dummy_latest_flush; + + /** @recovery_needed: True when a resume attempt failed. */ + atomic_t recovery_needed; } pm; /** @profile_mask: User-set profiling flags for job accounting. */ @@ -243,6 +247,28 @@ int panthor_device_mmap_io(struct panthor_device *ptdev, int panthor_device_resume(struct device *dev); int panthor_device_suspend(struct device *dev); +static inline int panthor_device_resume_and_get(struct panthor_device *ptdev) +{ + int ret = pm_runtime_resume_and_get(ptdev->base.dev); + + /* If the resume failed, we need to clear the runtime_error, which + * can done by forcing the RPM state to suspended. If multiple + * threads called panthor_device_resume_and_get(), we only want + * one of them to update the state, hence the cmpxchg. Note that a + * thread might enter panthor_device_resume_and_get() and call + * pm_runtime_resume_and_get() after another thread had attempted + * to resume and failed. This means we will end up with an error + * without even attempting a resume ourselves. The only risk here + * is to report an error when the second resume attempt might have + * succeeded. Given resume errors are not expected, this is probably + * something we can live with. + */ + if (ret && atomic_cmpxchg(&ptdev->pm.recovery_needed, 1, 0) == 1) + pm_runtime_set_suspended(ptdev->base.dev); + + return ret; +} + enum drm_panthor_exception_type { DRM_PANTHOR_EXCEPTION_OK = 0x00, DRM_PANTHOR_EXCEPTION_TERMINATED = 0x04, diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c index 1498c97b4b85..b7a9adc918e3 100644 --- a/drivers/gpu/drm/panthor/panthor_drv.c +++ b/drivers/gpu/drm/panthor/panthor_drv.c @@ -763,7 +763,7 @@ static int panthor_query_timestamp_info(struct panthor_device *ptdev, { int ret; - ret = pm_runtime_resume_and_get(ptdev->base.dev); + ret = panthor_device_resume_and_get(ptdev); if (ret) return ret; diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c index 97ed5fe5a191..77b184c3fb0c 100644 --- a/drivers/gpu/drm/panthor/panthor_sched.c +++ b/drivers/gpu/drm/panthor/panthor_sched.c @@ -2364,7 +2364,7 @@ static void tick_work(struct work_struct *work) if (!drm_dev_enter(&ptdev->base, &cookie)) return; - ret = pm_runtime_resume_and_get(ptdev->base.dev); + ret = panthor_device_resume_and_get(ptdev); if (drm_WARN_ON(&ptdev->base, ret)) goto out_dev_exit; @@ -3131,7 +3131,7 @@ queue_run_job(struct drm_sched_job *sched_job) return dma_fence_get(job->done_fence); } - ret = pm_runtime_resume_and_get(ptdev->base.dev); + ret = panthor_device_resume_and_get(ptdev); if (drm_WARN_ON(&ptdev->base, ret)) return ERR_PTR(ret);