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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 5BEB0C11F6B for ; Mon, 12 Jul 2021 08:15:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3F1B661419 for ; Mon, 12 Jul 2021 08:15:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357016AbhGLIQ5 (ORCPT ); Mon, 12 Jul 2021 04:16:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:51696 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242184AbhGLHc5 (ORCPT ); Mon, 12 Jul 2021 03:32:57 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id BE93A61165; Mon, 12 Jul 2021 07:30:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626075004; bh=GSD77wzJQT0u4ZwbGznBKDk4qcAEN/Y7q59TZSWcBy4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ntX/rVY+BYQMwSOXWSeONVUSIMRbRxZeQhtHzkVoPFJUR2jUHJxd/NKOy5jWhb4n3 Moo27R48YxTvywCJzk6xSjSkYf9++NhH/K/b8x74eX8hzUKafN4De2je1OnY9ri0Kj X33t418b/jVDFHWDmxxvQ6KpoZTYdNY1kAJlHe7s= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Baochen Qiang , Hemant Kumar , Manivannan Sadhasivam Subject: [PATCH 5.13 070/800] bus: mhi: Wait for M2 state during system resume Date: Mon, 12 Jul 2021 08:01:33 +0200 Message-Id: <20210712060923.078043789@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210712060912.995381202@linuxfoundation.org> References: <20210712060912.995381202@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Baochen Qiang commit 02b49cd1174527e611768fc2ce0f75a74dfec7ae upstream. 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 when CPU finally has time to process the ring, there will be two events: 1. For M3->M0 event, which is the first event to be processed queued first. The tasklet handler serves the event, updates device state to M0 and wakes up the task. 2. For M0->M1 event, which is processed later, the tasklet handler triggers M1->M2 transition and updates device state to M2 directly, then wakes up the MHI host (if it is 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 causing the M0 state to be 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 Cc: stable@vger.kernel.org Fixes: 0c6b20a1d720 ("bus: mhi: core: Add support for MHI suspend and resume") Signed-off-by: Baochen Qiang Reviewed-by: Hemant Kumar Reviewed-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/20210524040312.14409-1-bqiang@codeaurora.org [mani: slightly massaged the commit message] Signed-off-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/20210621161616.77524-4-manivannan.sadhasivam@linaro.org Signed-off-by: Greg Kroah-Hartman diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c index 704a5e225097..bbf6cd04861e 100644 --- a/drivers/bus/mhi/core/pm.c +++ b/drivers/bus/mhi/core/pm.c @@ -926,6 +926,7 @@ int mhi_pm_resume(struct mhi_controller *mhi_cntrl) ret = wait_event_timeout(mhi_cntrl->state_event, mhi_cntrl->dev_state == MHI_STATE_M0 || + mhi_cntrl->dev_state == MHI_STATE_M2 || MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state), msecs_to_jiffies(mhi_cntrl->timeout_ms));