From patchwork Fri Jan 8 20:54:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bhaumik Bhatt X-Patchwork-Id: 12007583 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=-11.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 C6A27C433E6 for ; Fri, 8 Jan 2021 20:56:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 936C023A7F for ; Fri, 8 Jan 2021 20:56:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729261AbhAHU4B (ORCPT ); Fri, 8 Jan 2021 15:56:01 -0500 Received: from m43-15.mailgun.net ([69.72.43.15]:24813 "EHLO m43-15.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729324AbhAHU4B (ORCPT ); Fri, 8 Jan 2021 15:56:01 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1610139336; h=Message-Id: Date: Subject: Cc: To: From: Sender; bh=X2w150Vpf9IlkyYn7sgO3StsBElUXz/GmcFMCSpVlRc=; b=ef4u7fSSZZ/bRe067b8NSUEd0RiP/cCYcdn8cQQxPpneJATzdyBEraDimkXS7rorNINygoAN ORMfiEi2DSKsJW1WVVRLAop0J3Xo9femIeJhrnZ8f+mSIXCUwKwvTawWfHO0MAOC5GcIgwqA UL5axEdIxK2kpiv1Qk5oLhADIn4= X-Mailgun-Sending-Ip: 69.72.43.15 X-Mailgun-Sid: WyI1MzIzYiIsICJsaW51eC1hcm0tbXNtQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n04.prod.us-west-2.postgun.com with SMTP id 5ff8c6a9d84bad35476d8582 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Fri, 08 Jan 2021 20:55:05 GMT Sender: bbhatt=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id C9421C43463; Fri, 8 Jan 2021 20:55:04 +0000 (UTC) Received: from malabar-linux.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: bbhatt) by smtp.codeaurora.org (Postfix) with ESMTPSA id C27BEC433CA; Fri, 8 Jan 2021 20:55:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org C27BEC433CA Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=bbhatt@codeaurora.org From: Bhaumik Bhatt To: manivannan.sadhasivam@linaro.org Cc: linux-arm-msm@vger.kernel.org, hemantk@codeaurora.org, jhugo@codeaurora.org, linux-kernel@vger.kernel.org, loic.poulain@linaro.org, Bhaumik Bhatt Subject: [PATCH v5 0/9] Updates to MHI channel handling Date: Fri, 8 Jan 2021 12:54:48 -0800 Message-Id: <1610139297-36435-1-git-send-email-bbhatt@codeaurora.org> X-Mailer: git-send-email 2.7.4 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org MHI specification shows a state machine with support for STOP channel command and the validity of certain state transitions. MHI host currently does not provide any mechanism to stop a channel and restart it without resetting it. There are also times when the device moves on to a different execution environment while client drivers on the host are unaware of it and still attempt to reset the channels facing unnecessary timeouts. This series addresses the above areas to provide support for stopping an MHI channel, resuming it back, improved documentation and improving upon channel state machine handling in general. This set of patches was tested on arm64 architecture. v5: -Added reviewed-by tags from Hemant I missed earlier -Added patch to prevent kernel warnings on clearing channel context twice v4: -Updated commit text/descriptions and addressed checkpatch checks -Added context validity check before starting/stopping channels from new API -Added patch to clear channel context configuration after reset/unprepare v3: -Updated documentation for channel transfer APIs to highlight differences -Create separate patch for "allowing channel to be disabled from stopped state" v2: -Renamed the newly introduced APIs to mhi_start_transfer() / mhi_stop_transfer() -Added improved documentation to avoid confusion with the new APIs -Removed the __ prefix from mhi_unprepare_channel() API for consistency. Bhaumik Bhatt (9): bus: mhi: core: Allow sending the STOP channel command bus: mhi: core: Allow channel to be disabled from stopped state bus: mhi: core: Improvements to the channel handling state machine bus: mhi: core: Clear configuration from channel context during reset bus: mhi: core: Add support to stop or start channel data transfers bus: mhi: core: Check channel execution environment before issuing reset bus: mhi: core: Remove __ prefix for MHI channel unprepare function bus: mhi: Improve documentation on channel transfer setup APIs bus: mhi: core: Do not clear channel context more than once drivers/bus/mhi/core/init.c | 23 +++- drivers/bus/mhi/core/internal.h | 12 ++ drivers/bus/mhi/core/main.c | 238 ++++++++++++++++++++++++++++------------ include/linux/mhi.h | 45 +++++++- 4 files changed, 243 insertions(+), 75 deletions(-)