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 A7C1CC11F67 for ; Mon, 12 Jul 2021 08:15:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9194B61413 for ; Mon, 12 Jul 2021 08:15:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356960AbhGLIQy (ORCPT ); Mon, 12 Jul 2021 04:16:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:54416 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240243AbhGLHc7 (ORCPT ); Mon, 12 Jul 2021 03:32:59 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id DF1DA60230; Mon, 12 Jul 2021 07:30:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626075001; bh=51hGTpUobY2VDKXE295OLpeHzJT02q2JldvUypcW9cE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mqrwjjLf6h27jmiNZUbbriHScJEu6nq8QjzZxI6YQnuXvTtuzctJEaIYbophmWcHc IOb77hNT3iP+Hbu3ZUCol89GLMZhnnRYnKycEKx5mgJDGiMX5vGnx3N65Ws22JiA5E uTYQUk9WnPksd2D5jG8U5OsqVyrTRdZt7XFXwjS8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Loic Poulain , Bhaumik Bhatt , Manivannan Sadhasivam , Hemant Kumar Subject: [PATCH 5.13 069/800] bus: mhi: core: Fix power down latency Date: Mon, 12 Jul 2021 08:01:32 +0200 Message-Id: <20210712060922.934921601@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: Loic Poulain commit 44b1eba44dc537edf076f131f1eeee7544d0e04f upstream. On graceful power-down/disable transition, when an MHI reset is performed, the MHI device loses its context, including interrupt configuration. However, the current implementation is waiting for event(irq) driven state change to confirm reset has been completed, which never happens, and causes reset timeout, leading to unexpected high latency of the mhi_power_down procedure (up to 45 seconds). Fix that by moving to the recently introduced poll_reg_field method, waiting for the reset bit to be cleared, in the same way as the power_on procedure. Cc: stable@vger.kernel.org Fixes: a6e2e3522f29 ("bus: mhi: core: Add support for PM state transitions") Signed-off-by: Loic Poulain Reviewed-by: Bhaumik Bhatt Reviewed-by: Manivannan Sadhasivam Reviewed-by: Hemant Kumar Link: https://lore.kernel.org/r/1620029090-8975-1-git-send-email-loic.poulain@linaro.org Signed-off-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/20210621161616.77524-3-manivannan.sadhasivam@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/bus/mhi/core/pm.c | 18 +++++------------- 1 file changed, 5 insertions(+), 13 deletions(-) --- a/drivers/bus/mhi/core/pm.c +++ b/drivers/bus/mhi/core/pm.c @@ -465,23 +465,15 @@ static void mhi_pm_disable_transition(st /* Trigger MHI RESET so that the device will not access host memory */ if (!MHI_PM_IN_FATAL_STATE(mhi_cntrl->pm_state)) { - u32 in_reset = -1; - unsigned long timeout = msecs_to_jiffies(mhi_cntrl->timeout_ms); - dev_dbg(dev, "Triggering MHI Reset in device\n"); mhi_set_mhi_state(mhi_cntrl, MHI_STATE_RESET); /* Wait for the reset bit to be cleared by the device */ - ret = wait_event_timeout(mhi_cntrl->state_event, - mhi_read_reg_field(mhi_cntrl, - mhi_cntrl->regs, - MHICTRL, - MHICTRL_RESET_MASK, - MHICTRL_RESET_SHIFT, - &in_reset) || - !in_reset, timeout); - if (!ret || in_reset) - dev_err(dev, "Device failed to exit MHI Reset state\n"); + ret = mhi_poll_reg_field(mhi_cntrl, mhi_cntrl->regs, MHICTRL, + MHICTRL_RESET_MASK, MHICTRL_RESET_SHIFT, 0, + 25000); + if (ret) + dev_err(dev, "Device failed to clear MHI Reset\n"); /* * Device will clear BHI_INTVEC as a part of RESET processing,