From patchwork Thu Feb 4 20:27:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bhaumik Bhatt X-Patchwork-Id: 12068635 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 49647C433E0 for ; Thu, 4 Feb 2021 20:29:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0524F64F45 for ; Thu, 4 Feb 2021 20:29:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240012AbhBDU3L (ORCPT ); Thu, 4 Feb 2021 15:29:11 -0500 Received: from so15.mailgun.net ([198.61.254.15]:27575 "EHLO so15.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238746AbhBDU3E (ORCPT ); Thu, 4 Feb 2021 15:29:04 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1612470521; h=Message-Id: Date: Subject: Cc: To: From: Sender; bh=vQ2EF5eRDQzzxbY0Yb+0v6gNppR10n77+3JxogqXiYw=; b=h6EjuHUkWxLGOi9K6JDvT9rwqGsKZkS6fO46TwxgtUqZaxCzdUVqKffAkK+44o0R/+xae0Nw G501Sj2fxeNH0/xUN2+sU1B+sqgt2J2OYPYhcosINCe3ZPdeNjwtTw2BZFTP1dCRxmzjiE4p I3GLPLUejm3VMKv/P4KRrVtPRYQ= X-Mailgun-Sending-Ip: 198.61.254.15 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-n02.prod.us-east-1.postgun.com with SMTP id 601c58de5d0f38478786647f (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Thu, 04 Feb 2021 20:28:14 GMT Sender: bbhatt=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 9D99DC433CA; Thu, 4 Feb 2021 20:28:13 +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 8D752C43461; Thu, 4 Feb 2021 20:28:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 8D752C43461 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 v6 0/8] Updates to MHI channel handling Date: Thu, 4 Feb 2021 12:27:58 -0800 Message-Id: <1612470486-10440-1-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. v6: -Dropped the patch which introduced start/stop transfer APIs for lack of users -Updated error handling and debug prints on channel handling improvements patch -Improved commit text to better explain certain patches based on review comments -Removed references to new APIs from the documentation improvement patch 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 (8): bus: mhi: core: Allow sending the STOP channel command bus: mhi: core: Clear context for stopped channels from remove() bus: mhi: core: Improvements to the channel handling state machine bus: mhi: core: Clear configuration from channel context during reset 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 | 192 ++++++++++++++++++++++++---------------- include/linux/mhi.h | 18 +++- 4 files changed, 164 insertions(+), 81 deletions(-)