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 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 572FBC636C9 for ; Wed, 21 Jul 2021 18:07:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 32D2360551 for ; Wed, 21 Jul 2021 18:07:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237911AbhGUR0f (ORCPT ); Wed, 21 Jul 2021 13:26:35 -0400 Received: from m43-7.mailgun.net ([69.72.43.7]:45445 "EHLO m43-7.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230425AbhGUR0e (ORCPT ); Wed, 21 Jul 2021 13:26:34 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1626890830; h=Message-ID: References: In-Reply-To: Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=1ecCHoTqii1kF3SXZuY2ai/ct4AwH6Dvx7aFp6vb+2M=; b=qWO1gmKlVleCGKYMVUw9u3M9LeW4coY+gj5GeCEIE1gTpDZBNn6iaglFaEzsUaqO3ZhzEKar DHM8t8IicAc0hgb6IvWW9tr4ElUEMBAtKyo6tkzcGdr2NvwBRe217TcwRnySln/q7O+/n8Wn KdfwyQegt+vDUNvjCEEOOlwzdK4= X-Mailgun-Sending-Ip: 69.72.43.7 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-n04.prod.us-east-1.postgun.com with SMTP id 60f862481dd16c878844d51a (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Wed, 21 Jul 2021 18:07:04 GMT Sender: bbhatt=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id C54A7C43460; Wed, 21 Jul 2021 18:07:03 +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 04DC7C433F1; Wed, 21 Jul 2021 18:07:02 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 21 Jul 2021 11:07:02 -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: <4214f00fa8cbcced4f389125b392f3b3@codeaurora.org> References: <1626831778-31796-1-git-send-email-bbhatt@codeaurora.org> <4214f00fa8cbcced4f389125b392f3b3@codeaurora.org> Message-ID: <0da23f32f4313c0b701bafc078942a4e@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 2021-07-21 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. >> @@ -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