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=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 56C30C4338F for ; Fri, 23 Jul 2021 02:46:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3DE2B60EB0 for ; Fri, 23 Jul 2021 02:46:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233460AbhGWCFZ (ORCPT ); Thu, 22 Jul 2021 22:05:25 -0400 Received: from m43-7.mailgun.net ([69.72.43.7]:25845 "EHLO m43-7.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233222AbhGWCFX (ORCPT ); Thu, 22 Jul 2021 22:05:23 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1627008357; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=JAyHez6aM2XLJzve+XkvTj/UUvYa/5JtayFnGjuVnuo=; b=VIkQwjUh2Qg1Eg1GVhATk7BE1u8WF8o1KL/WsKNb+O0MIEJVpxOzX+5u+KDEkLTz2k02MCuQ pWlyNPGpBBC0OC9WQHxjUWNR62hk3fzsOEjJe6QF1p04SBNX6AbzHAGX8JoUWEYaIa+o68JC qUpT4bpE82MkylzsY8gUchv3z6Q= 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-n07.prod.us-west-2.postgun.com with SMTP id 60fa2d61d0100c7cf9ea9ecb (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Fri, 23 Jul 2021 02:45:53 GMT Sender: hemantk=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id D6EE1C4338A; Fri, 23 Jul 2021 02:45:52 +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 5F868C433F1; Fri, 23 Jul 2021 02:45:52 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Thu, 22 Jul 2021 19:45:52 -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: <62daad3e0074400ee7011f55a6f255ac@codeaurora.org> References: <1626831778-31796-1-git-send-email-bbhatt@codeaurora.org> <4214f00fa8cbcced4f389125b392f3b3@codeaurora.org> <0da23f32f4313c0b701bafc078942a4e@codeaurora.org> <0e06bf8a7132cc9539e4d9b1e41b8863@codeaurora.org> <62daad3e0074400ee7011f55a6f255ac@codeaurora.org> Message-ID: <64bbb3db0e1bb33c03e31a6e467c9e42@codeaurora.org> 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 2021-07-22 12:50, Bhaumik Bhatt wrote: > 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. Thanks for checking that, Bhaumik. Reviewed-by: Hemant Kumar --- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project