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=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 CAF6EC6377A for ; Wed, 21 Jul 2021 22:27:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B34B161248 for ; Wed, 21 Jul 2021 22:27:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230090AbhGUVrO (ORCPT ); Wed, 21 Jul 2021 17:47:14 -0400 Received: from so254-9.mailgun.net ([198.61.254.9]:51311 "EHLO so254-9.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229794AbhGUVrM (ORCPT ); Wed, 21 Jul 2021 17:47:12 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1626906468; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=gxkqvfAkmupw/r15o2I7kgibu4nM6gPe+r3+Ugpvvcs=; b=TwJ2eSAVm31+QENUxSqfMW4ixwcfNTWlKmDsmgF68xvKdCOBZ8IB70hLDNqBtenR/f0l5FHC 6Gw/gmbjvrjZciYaW3FvCfxdJBTklYrIXI3vMqUTlyDw15I6zqGJ0ZC5Haokdw9fprDpQfML rVOJz44SWG3X4QV1x3sBzD3XlbY= 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-n01.prod.us-east-1.postgun.com with SMTP id 60f89f4d4815712f3a126eb6 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Wed, 21 Jul 2021 22:27:25 GMT Sender: hemantk=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 95F24C4338A; Wed, 21 Jul 2021 22:27:24 +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: hemantk) by smtp.codeaurora.org (Postfix) with ESMTPSA id 1DEFAC43460; Wed, 21 Jul 2021 22:27:24 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 21 Jul 2021 15:27:24 -0700 From: hemantk@codeaurora.org To: bbhatt@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 In-Reply-To: <0da23f32f4313c0b701bafc078942a4e@codeaurora.org> References: <1626831778-31796-1-git-send-email-bbhatt@codeaurora.org> <4214f00fa8cbcced4f389125b392f3b3@codeaurora.org> <0da23f32f4313c0b701bafc078942a4e@codeaurora.org> Message-ID: X-Sender: hemantk@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 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; ? > >>> @@ -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