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=-14.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 F2DC0C04FF3 for ; Mon, 24 May 2021 21:43:28 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id AD6D86140F for ; Mon, 24 May 2021 21:43:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AD6D86140F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=ath11k-bounces+ath11k=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=gwIe7dDp/WCQFTcpUAVq2HeialAXbMH2Dm3NkGpcYyU=; b=N8WXPleUT6XESN jxkgly5jYjGO7kx1iV4FLCeVZe93FBCyK6mbMUp2bpbr1LybGFK+6ixGO19Cl+p1/eqeYuLseml4x ycHpXV0Rb4yXyhDs7v+Kc2lNp4QsUJvTRnBOyF3TGnOHnT5xP9zwCO6z78wsott0gDFuy7RdHsitf 1EmB5V5yxHPNmhPmi5E0o+4RLE/4whkRJRtMwaicGtjxwh1KOLpasUoD6dk65cTczGpgwFgMP13zy 19zvE6aroeBJIXDM/WzlFHb/cYZ35Brmm6wIUwKDlmPGBwq7ZK1+MENyM9NzeX419BpDeXGWBopSp PMo+eG64y4aNXEywRuiw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1llIM9-001ywy-FU; Mon, 24 May 2021 21:43:25 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1ll4b3-000jHq-4n for ath11k@lists.infradead.org; Mon, 24 May 2021 07:01:54 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id A49BC60FEF; Mon, 24 May 2021 07:01:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621839711; bh=wae65KOcaAEsmwm5b4JIWjciQ5lLGB76byDWItyOH48=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=onN/sezX1sshCB0mmiddosdsLbGt4B1DkCIccD2p67O+zB5zG/SovvP30Nnq/FAV5 IKmn6cw0aUb8PVl8AUXmDWSJwgT2sLEeY3Th7bfUjNPc5S13gYQgecadGH04/WsoCM +lbTia6B1epI5dz9xhdKceX2Y4kkM+PvXcrqi7yk= Date: Mon, 24 May 2021 09:01:49 +0200 From: Greg KH To: Baochen Qiang Cc: manivannan.sadhasivam@linaro.org, hemantk@codeaurora.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, ath11k@lists.infradead.org, stable@vger.kernel.org Subject: Re: [PATCH v2] bus: mhi: Wait for M2 state during system resume Message-ID: References: <20210524040312.14409-1-bqiang@codeaurora.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210524040312.14409-1-bqiang@codeaurora.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210524_000153_255091_A8E7D49E X-CRM114-Status: GOOD ( 20.44 ) X-BeenThere: ath11k@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "ath11k" Errors-To: ath11k-bounces+ath11k=archiver.kernel.org@lists.infradead.org On Mon, May 24, 2021 at 12:03:12PM +0800, Baochen Qiang wrote: > During system resume, MHI host triggers M3->M0 transition and then waits > for target device to enter M0 state. Once done, the device queues a state > change event into ctrl event ring and notifies MHI host by raising an > interrupt, where a tasklet is scheduled to process this event. In most cases, > the tasklet is served timely and wait operation succeeds. > > However, there are cases where CPU is busy and cannot serve this tasklet > for some time. Once delay goes long enough, the device moves itself to M1 > state and also interrupts MHI host after inserting a new state change > event to ctrl ring. Later CPU finally has time to process the ring, however > there are two events in it now: > 1. for M3->M0 event, which is processed first as queued first, > tasklet handler updates device state to M0 and wakes up the task, > i.e., the MHI host. > 2. for M0->M1 event, which is processed later, tasklet handler > triggers M1->M2 transition and updates device state to M2 directly, > then wakes up the MHI host(if still sleeping on this wait queue). > Note that although MHI host has been woken up while processing the first > event, it may still has no chance to run before the second event is processed. > In other words, MHI host has to keep waiting till timeout cause the M0 state > has been missed. > > kernel log here: > ... > Apr 15 01:45:14 test-NUC8i7HVK kernel: [ 4247.911251] mhi 0000:06:00.0: Entered with PM state: M3, MHI state: M3 > Apr 15 01:45:14 test-NUC8i7HVK kernel: [ 4247.917762] mhi 0000:06:00.0: State change event to state: M0 > Apr 15 01:45:14 test-NUC8i7HVK kernel: [ 4247.917767] mhi 0000:06:00.0: State change event to state: M1 > Apr 15 01:45:14 test-NUC8i7HVK kernel: [ 4338.788231] mhi 0000:06:00.0: Did not enter M0 state, MHI state: M2, PM state: M2 > ... > > Fix this issue by simply adding M2 as a valid state for resume. > > Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-01720.1-QCAHSPSWPL_V1_V2_SILICONZ_LITE-1 > > Fixes: 0c6b20a1d720 ("bus: mhi: core: Add support for MHI suspend and resume") > Signed-off-by: Baochen Qiang > Reviewed-by: Hemant Kumar > --- > drivers/bus/mhi/core/pm.c | 1 + > 1 file changed, 1 insertion(+) This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html for how to do this properly. -- ath11k mailing list ath11k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath11k