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=-13.8 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 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 E2C08C4338F for ; Thu, 22 Jul 2021 19:50:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C93AE60EB1 for ; Thu, 22 Jul 2021 19:50:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230426AbhGVTKJ (ORCPT ); Thu, 22 Jul 2021 15:10:09 -0400 Received: from so254-9.mailgun.net ([198.61.254.9]:16068 "EHLO so254-9.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230424AbhGVTKD (ORCPT ); Thu, 22 Jul 2021 15:10:03 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1626983438; h=Message-ID: References: In-Reply-To: Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=bBVqSY6i8vfMhg4A9+M4eCLLJvU7ydQvACGifQY2egc=; b=WWBBSzvwVjXOyea+/wDvcFHcN6sENDsLIgO4pSRCUcvTh8Y2A443NIhgK8O+tQ9jlu1xdpvN KosRsW8621n082M7CZ/xjmuO7ECq47K33cD8Jytj/S9QASaVliYu32FqlCnrCQ9n3GeBt6Vg TTXZqOFT8OMrKytFdkUsFCsBBwA= X-Mailgun-Sending-Ip: 198.61.254.9 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n03.prod.us-west-2.postgun.com with SMTP id 60f9cc0afcf9fe7b78f9af3c (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Thu, 22 Jul 2021 19:50:34 GMT Sender: bbhatt=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 1924DC43143; Thu, 22 Jul 2021 19:50:34 +0000 (UTC) Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: bbhatt) by smtp.codeaurora.org (Postfix) with ESMTPSA id DD67CC43460; Thu, 22 Jul 2021 19:50:32 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Thu, 22 Jul 2021 12:50:32 -0700 From: Bhaumik Bhatt To: hemantk@codeaurora.org Cc: manivannan.sadhasivam@linaro.org, bqiang@codeaurora.org, linux-arm-msm@vger.kernel.org, clew@codeaurora.org, linux-kernel@vger.kernel.org, bbhatt=codeaurora.org@codeaurora.org, hemantk=codeaurora.org@codeaurora.org Subject: Re: [PATCH] net: qrtr: mhi: synchronize qrtr and mhi preparation Organization: Qualcomm Innovation Center, Inc. Reply-To: bbhatt@codeaurora.org Mail-Reply-To: bbhatt@codeaurora.org In-Reply-To: <0e06bf8a7132cc9539e4d9b1e41b8863@codeaurora.org> References: <1626831778-31796-1-git-send-email-bbhatt@codeaurora.org> <4214f00fa8cbcced4f389125b392f3b3@codeaurora.org> <0da23f32f4313c0b701bafc078942a4e@codeaurora.org> <0e06bf8a7132cc9539e4d9b1e41b8863@codeaurora.org> Message-ID: <62daad3e0074400ee7011f55a6f255ac@codeaurora.org> X-Sender: bbhatt@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-07-22 12:04 PM, Bhaumik Bhatt wrote: > On 2021-07-21 03:27 PM, hemantk@codeaurora.org wrote: >> On 2021-07-21 11:07, Bhaumik Bhatt wrote: >>> On 2021-07-21 10:52 AM, hemantk@codeaurora.org wrote: >>>> On 2021-07-20 18:42, Bhaumik Bhatt wrote: >>>>> A dl callback can be received anytime after >>>>> mhi_prepare_for_transfer >>>>> has been called. There is a window where the callback may happen >>>>> before the probe initializes the qrtr_mhi_dev state. Move the >>>>> mhi_prepare_for_transfer call after the registering the endpoint. >>>>> >>>>> Once moved, the reverse can happen where qrtr will try to send a >>>>> packet >>>>> before the channels are prepared. Add a wait in the sending path to >>>>> ensure the channels are prepared before trying to do a ul transfer. >>>>> >>>>> Fixes: a2e2cc0dbb11 ("net: qrtr: Start MHI channels during init") >>>>> Signed-off-by: Bhaumik Bhatt >>>>> --- >>>>> net/qrtr/mhi.c | 20 +++++++++++++++----- >>>>> 1 file changed, 15 insertions(+), 5 deletions(-) >>>>> >>>>> diff --git a/net/qrtr/mhi.c b/net/qrtr/mhi.c >>>>> index 29b4fa3..22b0395 100644 >>>>> --- a/net/qrtr/mhi.c >>>>> +++ b/net/qrtr/mhi.c >>>>> @@ -15,6 +15,7 @@ struct qrtr_mhi_dev { >>>>> struct qrtr_endpoint ep; >>>>> struct mhi_device *mhi_dev; >>>>> struct device *dev; >>>>> + struct completion ready; >>>>> }; >>>>> >>>>> /* From MHI to QRTR */ >>>>> @@ -50,6 +51,10 @@ static int qcom_mhi_qrtr_send(struct >>>>> qrtr_endpoint >>>>> *ep, struct sk_buff *skb) >>>>> struct qrtr_mhi_dev *qdev = container_of(ep, struct qrtr_mhi_dev, >>>>> ep); >>>>> int rc; >>>>> >>>>> + rc = wait_for_completion_interruptible(&qdev->ready); >>>>> + if (rc) >>>>> + goto free_skb; >>>>> + >>>>> if (skb->sk) >>>>> sock_hold(skb->sk); >>>>> >>>>> @@ -78,11 +83,6 @@ static int qcom_mhi_qrtr_probe(struct mhi_device >>>>> *mhi_dev, >>>>> struct qrtr_mhi_dev *qdev; >>>>> int rc; >>>>> >>>>> - /* start channels */ >>>>> - rc = mhi_prepare_for_transfer(mhi_dev, >>>>> MHI_CH_INBOUND_ALLOC_BUFS); >>>>> - if (rc) >>>>> - return rc; >>>>> - >>>>> qdev = devm_kzalloc(&mhi_dev->dev, sizeof(*qdev), GFP_KERNEL); >>>>> if (!qdev) >>>>> return -ENOMEM; >>>> would it be good to init completion variable here (call >>>> init_completion) ? >>> You mean just before setting qdev->mhi_dev? I don't see why that >>> would >>> make a difference >>> mainly because the qcom_mhi_qrtr_send() will only happen after >>> endpoint is >>> registered and DL xfer cb will also only come in after we have >>> prepared the >>> channels and completed ready with dev_data already set. >> looks like qcom_mhi_qrtr_send is not going to get called directly. i >> was thinking >> what if this api is called before init_completion() returns. if it is >> only possible >> through ep.xmit call back only, can you move it right above >> qdev->ep.xmit = qcom_mhi_qrtr_send; ? >>> > Ah. OK. I see your point. I will do that and upload a v2. > On second thought, this is not required because the ep.xmit() will not be called until the qrtr_endpoint_register() is done. So this version should be fine IMO. >>>>> @@ -90,12 +90,22 @@ static int qcom_mhi_qrtr_probe(struct >>>>> mhi_device *mhi_dev, >>>>> qdev->mhi_dev = mhi_dev; >>>>> qdev->dev = &mhi_dev->dev; >>>>> qdev->ep.xmit = qcom_mhi_qrtr_send; >>>>> + init_completion(&qdev->ready); >>>>> >>>> >>>>> >>>>> return 0; >>> >>> Thanks, >>> Bhaumik >>> --- >>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora >>> Forum, >>> a Linux Foundation Collaborative Project >> >> Thanks, >> Hemant >> --- >> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora >> Forum, >> a Linux Foundation Collaborative Project > > Thanks, > Bhaumik > --- > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora > Forum, > a Linux Foundation Collaborative Project Thanks, Bhaumik --- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project