From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 66814C433F5 for ; Thu, 16 Sep 2021 13:05:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4A7E360F48 for ; Thu, 16 Sep 2021 13:05:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239901AbhIPNGq (ORCPT ); Thu, 16 Sep 2021 09:06:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:57248 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239699AbhIPNGq (ORCPT ); Thu, 16 Sep 2021 09:06:46 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3EB8860ED7; Thu, 16 Sep 2021 13:05:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1631797525; bh=tMCxi8HdimCGu2hYlHHllEj6eJ0aYHkjxfmMs9YhhYI=; h=Subject:To:Cc:From:Date:From; b=hoWypV/5gQ2/q2tfzkM4xH1mnuL9hu0LYishysyV7mQ7TR6MGMnFNSn/mub9FeJZ7 JgwMce4sN8ajTLlAJ9P/KOafyzOfSFWeCDvMSNwsYYVEyYYcnQeQ3H4CqXTQal5hn8 s1QeEw4vA0nL/SCVyJJho4SAXVfNAuGP+TIp3wUQ= Subject: FAILED: patch "[PATCH] drm/amdgpu: Cancel delayed work when GFXOFF is disabled" failed to apply to 5.14-stable tree To: mdaenzer@redhat.com, alexander.deucher@amd.com, christian.koenig@amd.com, evan.quan@amd.com, lijo.lazar@amd.com Cc: From: Date: Thu, 16 Sep 2021 15:05:23 +0200 Message-ID: <163179752354221@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 90a9266269eb9f71af1f323c33e1dca53527bd22 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Michel=20D=C3=A4nzer?= Date: Tue, 17 Aug 2021 10:23:25 +0200 Subject: [PATCH] drm/amdgpu: Cancel delayed work when GFXOFF is disabled MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit schedule_delayed_work does not push back the work if it was already scheduled before, so amdgpu_device_delay_enable_gfx_off ran ~100 ms after the first time GFXOFF was disabled and re-enabled, even if GFXOFF was disabled and re-enabled again during those 100 ms. This resulted in frame drops / stutter with the upcoming mutter 41 release on Navi 14, due to constantly enabling GFXOFF in the HW and disabling it again (for getting the GPU clock counter). To fix this, call cancel_delayed_work_sync when the disable count transitions from 0 to 1, and only schedule the delayed work on the reverse transition, not if the disable count was already 0. This makes sure the delayed work doesn't run at unexpected times, and allows it to be lock-free. v2: * Use cancel_delayed_work_sync & mutex_trylock instead of mod_delayed_work. v3: * Make amdgpu_device_delay_enable_gfx_off lock-free (Christian König) v4: * Fix race condition between amdgpu_gfx_off_ctrl incrementing adev->gfx.gfx_off_req_count and amdgpu_device_delay_enable_gfx_off checking for it to be 0 (Evan Quan) Cc: stable@vger.kernel.org Reviewed-by: Evan Quan Reviewed-by: Lijo Lazar # v3 Acked-by: Christian König # v3 Signed-off-by: Michel Dänzer Signed-off-by: Alex Deucher diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c index 41cc00e489ac..41c6b3aacd37 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c @@ -2829,12 +2829,11 @@ static void amdgpu_device_delay_enable_gfx_off(struct work_struct *work) struct amdgpu_device *adev = container_of(work, struct amdgpu_device, gfx.gfx_off_delay_work.work); - mutex_lock(&adev->gfx.gfx_off_mutex); - if (!adev->gfx.gfx_off_state && !adev->gfx.gfx_off_req_count) { - if (!amdgpu_dpm_set_powergating_by_smu(adev, AMD_IP_BLOCK_TYPE_GFX, true)) - adev->gfx.gfx_off_state = true; - } - mutex_unlock(&adev->gfx.gfx_off_mutex); + WARN_ON_ONCE(adev->gfx.gfx_off_state); + WARN_ON_ONCE(adev->gfx.gfx_off_req_count); + + if (!amdgpu_dpm_set_powergating_by_smu(adev, AMD_IP_BLOCK_TYPE_GFX, true)) + adev->gfx.gfx_off_state = true; } /** diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c index e7e9655c5623..e7f06bd0f0cd 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c @@ -563,24 +563,38 @@ void amdgpu_gfx_off_ctrl(struct amdgpu_device *adev, bool enable) mutex_lock(&adev->gfx.gfx_off_mutex); - if (!enable) - adev->gfx.gfx_off_req_count++; - else if (adev->gfx.gfx_off_req_count > 0) + if (enable) { + /* If the count is already 0, it means there's an imbalance bug somewhere. + * Note that the bug may be in a different caller than the one which triggers the + * WARN_ON_ONCE. + */ + if (WARN_ON_ONCE(adev->gfx.gfx_off_req_count == 0)) + goto unlock; + adev->gfx.gfx_off_req_count--; - if (enable && !adev->gfx.gfx_off_state && !adev->gfx.gfx_off_req_count) { - schedule_delayed_work(&adev->gfx.gfx_off_delay_work, GFX_OFF_DELAY_ENABLE); - } else if (!enable && adev->gfx.gfx_off_state) { - if (!amdgpu_dpm_set_powergating_by_smu(adev, AMD_IP_BLOCK_TYPE_GFX, false)) { - adev->gfx.gfx_off_state = false; + if (adev->gfx.gfx_off_req_count == 0 && !adev->gfx.gfx_off_state) + schedule_delayed_work(&adev->gfx.gfx_off_delay_work, GFX_OFF_DELAY_ENABLE); + } else { + if (adev->gfx.gfx_off_req_count == 0) { + cancel_delayed_work_sync(&adev->gfx.gfx_off_delay_work); + + if (adev->gfx.gfx_off_state && + !amdgpu_dpm_set_powergating_by_smu(adev, AMD_IP_BLOCK_TYPE_GFX, false)) { + adev->gfx.gfx_off_state = false; - if (adev->gfx.funcs->init_spm_golden) { - dev_dbg(adev->dev, "GFXOFF is disabled, re-init SPM golden settings\n"); - amdgpu_gfx_init_spm_golden(adev); + if (adev->gfx.funcs->init_spm_golden) { + dev_dbg(adev->dev, + "GFXOFF is disabled, re-init SPM golden settings\n"); + amdgpu_gfx_init_spm_golden(adev); + } } } + + adev->gfx.gfx_off_req_count++; } +unlock: mutex_unlock(&adev->gfx.gfx_off_mutex); }