From patchwork Tue Mar 30 02:11:43 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bhaumik Bhatt X-Patchwork-Id: 12171425 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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 B4F4CC433C1 for ; Tue, 30 Mar 2021 02:13:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6E5F561989 for ; Tue, 30 Mar 2021 02:13:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230374AbhC3CNG (ORCPT ); Mon, 29 Mar 2021 22:13:06 -0400 Received: from m43-7.mailgun.net ([69.72.43.7]:39855 "EHLO m43-7.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231124AbhC3CMf (ORCPT ); Mon, 29 Mar 2021 22:12:35 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1617070355; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=HbYaNgyNeFbk0nDsG5ClupSKKEdMGRxtJR+vdDmCTfQ=; b=pUw2RDF1+LfEghJP8zypEmfZV/3NJ2KOXgUlxuJbg8+96braGqHxuaThPvQAmnq/3+Gczh6K GW6AeopcRst7PQHpNGpJ3Ga5zCdIT3V28Vi3e1fAfQgdrwiZ9Y+mPZ1V0GQCCsUPqo3AvcCl M7eGEpJ1uENmg6gy4MR77abD4Nk= X-Mailgun-Sending-Ip: 69.72.43.7 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-n05.prod.us-west-2.postgun.com with SMTP id 606288fb3f0cbfdaf2640049 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 30 Mar 2021 02:12:11 GMT Sender: bbhatt=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 5485DC43464; Tue, 30 Mar 2021 02:12:11 +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 946EAC43463; Tue, 30 Mar 2021 02:12:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 946EAC43463 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, carl.yin@quectel.com, naveen.kumar@quectel.com, loic.poulain@linaro.org, Bhaumik Bhatt Subject: [PATCH v7 3/7] bus: mhi: core: Improvements to the channel handling state machine Date: Mon, 29 Mar 2021 19:11:43 -0700 Message-Id: <1617070307-5775-4-git-send-email-bbhatt@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1617070307-5775-1-git-send-email-bbhatt@codeaurora.org> References: <1617070307-5775-1-git-send-email-bbhatt@codeaurora.org> Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Improve the channel handling state machine such that all commands go through a common function and a validation process to ensure that the state machine is not violated in any way and adheres to the MHI specification. Using this common function allows MHI to: 1. Fail early if device is in a bad state by attempting to assert device wake before sending a channel update command instead of performing a wake toggle and waiting longer for the send to fail 2. Use channel specific print messages to accurately identify the use client device for the channel(s) being updated 3. Eliminate unnecessary debug messages and code duplication Signed-off-by: Bhaumik Bhatt Reviewed-by: Hemant Kumar --- drivers/bus/mhi/core/init.c | 6 ++ drivers/bus/mhi/core/internal.h | 12 +++ drivers/bus/mhi/core/main.c | 172 ++++++++++++++++++++++------------------ 3 files changed, 114 insertions(+), 76 deletions(-) diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c index bd62efcb..64846c4 100644 --- a/drivers/bus/mhi/core/init.c +++ b/drivers/bus/mhi/core/init.c @@ -54,6 +54,12 @@ const char * const mhi_state_str[MHI_STATE_MAX] = { [MHI_STATE_SYS_ERR] = "SYS_ERR", }; +const char * const mhi_ch_state_type_str[MHI_CH_STATE_TYPE_MAX] = { + [MHI_CH_STATE_TYPE_RESET] = "RESET", + [MHI_CH_STATE_TYPE_STOP] = "STOP", + [MHI_CH_STATE_TYPE_START] = "START", +}; + static const char * const mhi_pm_state_str[] = { [MHI_PM_STATE_DISABLE] = "DISABLE", [MHI_PM_STATE_POR] = "POR", diff --git a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h index 6f37439..d8fd197 100644 --- a/drivers/bus/mhi/core/internal.h +++ b/drivers/bus/mhi/core/internal.h @@ -369,6 +369,18 @@ enum mhi_ch_state { MHI_CH_STATE_ERROR = 0x5, }; +enum mhi_ch_state_type { + MHI_CH_STATE_TYPE_RESET, + MHI_CH_STATE_TYPE_STOP, + MHI_CH_STATE_TYPE_START, + MHI_CH_STATE_TYPE_MAX, +}; + +extern const char * const mhi_ch_state_type_str[MHI_CH_STATE_TYPE_MAX]; +#define TO_CH_STATE_TYPE_STR(state) (((state) >= MHI_CH_STATE_TYPE_MAX) ? \ + "INVALID_STATE" : \ + mhi_ch_state_type_str[(state)]) + #define MHI_INVALID_BRSTMODE(mode) (mode != MHI_DB_BRST_DISABLE && \ mode != MHI_DB_BRST_ENABLE) diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c index 0dc3749..6c3234e 100644 --- a/drivers/bus/mhi/core/main.c +++ b/drivers/bus/mhi/core/main.c @@ -1208,56 +1208,114 @@ int mhi_send_cmd(struct mhi_controller *mhi_cntrl, return 0; } -static void __mhi_unprepare_channel(struct mhi_controller *mhi_cntrl, - struct mhi_chan *mhi_chan) +static int mhi_update_channel_state(struct mhi_controller *mhi_cntrl, + struct mhi_chan *mhi_chan, + enum mhi_ch_state_type to_state) { - int ret; - struct device *dev = &mhi_cntrl->mhi_dev->dev; + struct device *dev = &mhi_chan->mhi_dev->dev; + enum mhi_cmd_type cmd = MHI_CMD_NOP; + int ret = -EIO; + + dev_dbg(dev, "%d: Updating channel state to: %s\n", mhi_chan->chan, + TO_CH_STATE_TYPE_STR(to_state)); + + switch (to_state) { + case MHI_CH_STATE_TYPE_RESET: + write_lock_irq(&mhi_chan->lock); + if (mhi_chan->ch_state != MHI_CH_STATE_STOP && + mhi_chan->ch_state != MHI_CH_STATE_ENABLED && + mhi_chan->ch_state != MHI_CH_STATE_SUSPENDED) { + write_unlock_irq(&mhi_chan->lock); + return -EINVAL; + } + mhi_chan->ch_state = MHI_CH_STATE_DISABLED; + write_unlock_irq(&mhi_chan->lock); - dev_dbg(dev, "Entered: unprepare channel:%d\n", mhi_chan->chan); + cmd = MHI_CMD_RESET_CHAN; + break; + case MHI_CH_STATE_TYPE_STOP: + if (mhi_chan->ch_state != MHI_CH_STATE_ENABLED) + return -EINVAL; - /* no more processing events for this channel */ - mutex_lock(&mhi_chan->mutex); - write_lock_irq(&mhi_chan->lock); - if (mhi_chan->ch_state != MHI_CH_STATE_ENABLED && - mhi_chan->ch_state != MHI_CH_STATE_SUSPENDED) { - write_unlock_irq(&mhi_chan->lock); - mutex_unlock(&mhi_chan->mutex); - return; + cmd = MHI_CMD_STOP_CHAN; + break; + case MHI_CH_STATE_TYPE_START: + if (mhi_chan->ch_state != MHI_CH_STATE_STOP && + mhi_chan->ch_state != MHI_CH_STATE_DISABLED) + return -EINVAL; + + cmd = MHI_CMD_START_CHAN; + break; + default: + dev_err(dev, "%d: Channel state update to %s not allowed\n", + mhi_chan->chan, TO_CH_STATE_TYPE_STR(to_state)); + return -EINVAL; } - mhi_chan->ch_state = MHI_CH_STATE_DISABLED; - write_unlock_irq(&mhi_chan->lock); + /* bring host and device out of suspended states */ + ret = mhi_device_get_sync(mhi_cntrl->mhi_dev); + if (ret) + return ret; + mhi_cntrl->runtime_get(mhi_cntrl); reinit_completion(&mhi_chan->completion); - read_lock_bh(&mhi_cntrl->pm_lock); - if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) { - read_unlock_bh(&mhi_cntrl->pm_lock); - goto error_invalid_state; + ret = mhi_send_cmd(mhi_cntrl, mhi_chan, cmd); + if (ret) { + dev_err(dev, "%d: Failed to send %s channel command\n", + mhi_chan->chan, TO_CH_STATE_TYPE_STR(to_state)); + goto exit_channel_update; } - mhi_cntrl->wake_toggle(mhi_cntrl); - read_unlock_bh(&mhi_cntrl->pm_lock); + ret = wait_for_completion_timeout(&mhi_chan->completion, + msecs_to_jiffies(mhi_cntrl->timeout_ms)); + if (!ret || mhi_chan->ccs != MHI_EV_CC_SUCCESS) { + dev_err(dev, + "%d: Failed to receive %s channel command completion\n", + mhi_chan->chan, TO_CH_STATE_TYPE_STR(to_state)); + ret = -EIO; + goto exit_channel_update; + } - mhi_cntrl->runtime_get(mhi_cntrl); + ret = 0; + + if (to_state != MHI_CH_STATE_TYPE_RESET) { + write_lock_irq(&mhi_chan->lock); + mhi_chan->ch_state = (to_state == MHI_CH_STATE_TYPE_START) ? + MHI_CH_STATE_ENABLED : MHI_CH_STATE_STOP; + write_unlock_irq(&mhi_chan->lock); + } + + dev_dbg(dev, "%d: Channel state change to %s successful\n", + mhi_chan->chan, TO_CH_STATE_TYPE_STR(to_state)); + +exit_channel_update: mhi_cntrl->runtime_put(mhi_cntrl); - ret = mhi_send_cmd(mhi_cntrl, mhi_chan, MHI_CMD_RESET_CHAN); - if (ret) - goto error_invalid_state; + mhi_device_put(mhi_cntrl->mhi_dev); - /* even if it fails we will still reset */ - ret = wait_for_completion_timeout(&mhi_chan->completion, - msecs_to_jiffies(mhi_cntrl->timeout_ms)); - if (!ret || mhi_chan->ccs != MHI_EV_CC_SUCCESS) - dev_err(dev, - "Failed to receive cmd completion, still resetting\n"); + return ret; +} + +static void __mhi_unprepare_channel(struct mhi_controller *mhi_cntrl, + struct mhi_chan *mhi_chan) +{ + int ret; + struct device *dev = &mhi_chan->mhi_dev->dev; + + mutex_lock(&mhi_chan->mutex); + + /* no more processing events for this channel */ + ret = mhi_update_channel_state(mhi_cntrl, mhi_chan, + MHI_CH_STATE_TYPE_RESET); + if (ret) + dev_err(dev, "%d: Failed to reset channel, still resetting\n", + mhi_chan->chan); -error_invalid_state: if (!mhi_chan->offload_ch) { mhi_reset_chan(mhi_cntrl, mhi_chan); mhi_deinit_chan_ctxt(mhi_cntrl, mhi_chan); } - dev_dbg(dev, "chan:%d successfully resetted\n", mhi_chan->chan); + dev_dbg(dev, "%d: successfully reset\n", mhi_chan->chan); + mutex_unlock(&mhi_chan->mutex); } @@ -1265,28 +1323,16 @@ int mhi_prepare_channel(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan) { int ret = 0; - struct device *dev = &mhi_cntrl->mhi_dev->dev; - - dev_dbg(dev, "Preparing channel: %d\n", mhi_chan->chan); + struct device *dev = &mhi_chan->mhi_dev->dev; if (!(BIT(mhi_cntrl->ee) & mhi_chan->ee_mask)) { - dev_err(dev, - "Current EE: %s Required EE Mask: 0x%x for chan: %s\n", - TO_MHI_EXEC_STR(mhi_cntrl->ee), mhi_chan->ee_mask, - mhi_chan->name); + dev_err(dev, "Current EE: %s Required EE Mask: 0x%x\n", + TO_MHI_EXEC_STR(mhi_cntrl->ee), mhi_chan->ee_mask); return -ENOTCONN; } mutex_lock(&mhi_chan->mutex); - /* If channel is not in disable state, do not allow it to start */ - if (mhi_chan->ch_state != MHI_CH_STATE_DISABLED) { - ret = -EIO; - dev_dbg(dev, "channel: %d is not in disabled state\n", - mhi_chan->chan); - goto error_init_chan; - } - /* Check of client manages channel context for offload channels */ if (!mhi_chan->offload_ch) { ret = mhi_init_chan_ctxt(mhi_cntrl, mhi_chan); @@ -1294,34 +1340,11 @@ int mhi_prepare_channel(struct mhi_controller *mhi_cntrl, goto error_init_chan; } - reinit_completion(&mhi_chan->completion); - read_lock_bh(&mhi_cntrl->pm_lock); - if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) { - read_unlock_bh(&mhi_cntrl->pm_lock); - ret = -EIO; - goto error_pm_state; - } - - mhi_cntrl->wake_toggle(mhi_cntrl); - read_unlock_bh(&mhi_cntrl->pm_lock); - mhi_cntrl->runtime_get(mhi_cntrl); - mhi_cntrl->runtime_put(mhi_cntrl); - - ret = mhi_send_cmd(mhi_cntrl, mhi_chan, MHI_CMD_START_CHAN); + ret = mhi_update_channel_state(mhi_cntrl, mhi_chan, + MHI_CH_STATE_TYPE_START); if (ret) goto error_pm_state; - ret = wait_for_completion_timeout(&mhi_chan->completion, - msecs_to_jiffies(mhi_cntrl->timeout_ms)); - if (!ret || mhi_chan->ccs != MHI_EV_CC_SUCCESS) { - ret = -EIO; - goto error_pm_state; - } - - write_lock_irq(&mhi_chan->lock); - mhi_chan->ch_state = MHI_CH_STATE_ENABLED; - write_unlock_irq(&mhi_chan->lock); - /* Pre-allocate buffer for xfer ring */ if (mhi_chan->pre_alloc) { int nr_el = get_nr_avail_ring_elements(mhi_cntrl, @@ -1359,9 +1382,6 @@ int mhi_prepare_channel(struct mhi_controller *mhi_cntrl, mutex_unlock(&mhi_chan->mutex); - dev_dbg(dev, "Chan: %d successfully moved to start state\n", - mhi_chan->chan); - return 0; error_pm_state: