From patchwork Thu Aug 31 13:08:26 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?b?UGV0ZXIgV2FuZyAo546L5L+h5Y+LKQ==?= X-Patchwork-Id: 719864 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BAC7AC83F33 for ; Thu, 31 Aug 2023 13:08:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242985AbjHaNIq (ORCPT ); Thu, 31 Aug 2023 09:08:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58016 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240495AbjHaNIj (ORCPT ); Thu, 31 Aug 2023 09:08:39 -0400 Received: from mailgw01.mediatek.com (unknown [60.244.123.138]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3EF57BC for ; Thu, 31 Aug 2023 06:08:37 -0700 (PDT) X-UUID: 7beef2e847ff11ee99480b3a0002f391-20230831 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:CC:To:From; bh=MtZHyXQ7DGRPhpbCpbsIJoEBq+bGheQvQ3n4RUzQzJQ=; b=T1D94anUrA3pbS5+DXxwEZs6I6ep9KcWaLV9BKz8hud1JtV15G6Elp9mnl0GdRpsTXB2hAdiFKP+Ut5zeu+4nU14jH/MQmEDsbYMsKimA7eYsXxVWildY4Hw3hdz4oFZzYUPeZUhGPcwasF3P43oMR8tP+EtBtZMYktDs2HFAGM=; X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.31, REQID:667197a7-a905-4338-9923-296fb7fa9d56, IP:0, U RL:0,TC:0,Content:-5,EDM:0,RT:0,SF:0,FILE:0,BULK:0,RULE:Release_Ham,ACTION :release,TS:-5 X-CID-META: VersionHash:0ad78a4, CLOUDID:8d64f81f-33fd-4aaa-bb43-d3fd68d9d5ae, B ulkID:nil,BulkQuantity:0,Recheck:0,SF:102,TC:nil,Content:0,EDM:-3,IP:nil,U RL:11|1,File:nil,Bulk:nil,QS:nil,BEC:nil,COL:0,OSI:0,OSA:0,AV:0,LES:1,SPR: NO,DKR:0,DKP:0,BRR:0,BRE:0 X-CID-BVR: 0,NGT X-CID-BAS: 0,NGT,0,_ X-CID-FACTOR: TF_CID_SPAM_SNR,TF_CID_SPAM_ULN X-UUID: 7beef2e847ff11ee99480b3a0002f391-20230831 Received: from mtkmbs11n2.mediatek.inc [(172.21.101.187)] by mailgw01.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 769978467; Thu, 31 Aug 2023 21:08:31 +0800 Received: from mtkmbs11n1.mediatek.inc (172.21.101.185) by mtkmbs10n2.mediatek.inc (172.21.101.183) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.26; Thu, 31 Aug 2023 21:08:30 +0800 Received: from mtksdccf07.mediatek.inc (172.21.84.99) by mtkmbs11n1.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.2.1118.26 via Frontend Transport; Thu, 31 Aug 2023 21:08:30 +0800 From: To: , , , , , CC: , , , , , , , , , , , , , Subject: [PATCH v2 3/3] ufs: core: fix abnormal scale up after scale down Date: Thu, 31 Aug 2023 21:08:26 +0800 Message-ID: <20230831130826.5592-4-peter.wang@mediatek.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20230831130826.5592-1-peter.wang@mediatek.com> References: <20230831130826.5592-1-peter.wang@mediatek.com> MIME-Version: 1.0 X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org From: Peter Wang When no active_reqs, devfreq_monitor(Thread A) will suspend clock scaling. But it may have racing with clk_scaling.suspend_work(Thread B) and actually not suspend clock scaling(requue after suspend). Next time after polling_ms, devfreq_monitor read clk_scaling.window_start_t = 0 then scale up clock abnormal. Below is racing step: devfreq->work (Thread A) devfreq_monitor update_devfreq ..... ufshcd_devfreq_target queue_work(hba->clk_scaling.workq, 1 &hba->clk_scaling.suspend_work) ..... 5 queue_delayed_work(devfreq_wq, &devfreq->work, msecs_to_jiffies(devfreq->profile->polling_ms)); 2 hba->clk_scaling.suspend_work (Thread B) ufshcd_clk_scaling_suspend_work __ufshcd_suspend_clkscaling devfreq_suspend_device(hba->devfreq); 3 cancel_delayed_work_sync(&devfreq->work); 4 hba->clk_scaling.window_start_t = 0; ..... Signed-off-by: Peter Wang Reviewed-by: Bart Van Assche --- drivers/ufs/core/ufshcd.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c index 057549b0e586..d72fa2c1e316 100644 --- a/drivers/ufs/core/ufshcd.c +++ b/drivers/ufs/core/ufshcd.c @@ -1430,6 +1430,13 @@ static int ufshcd_devfreq_target(struct device *dev, return 0; } + /* Skip scaling clock when clock scaling is suspended */ + if (hba->clk_scaling.is_suspended) { + spin_unlock_irqrestore(hba->host->host_lock, irq_flags); + dev_warn(hba->dev, "clock scaling is suspended, skip"); + return 0; + } + if (!hba->clk_scaling.active_reqs) sched_clk_scaling_suspend_work = true;