From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1B4F91E32B2; Fri, 8 Nov 2024 10:32:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731061959; cv=none; b=Xrt8AmF+xkWE/Qri6yGBsJ+ghNLjIrBbFb3o7uMBKKE+zhaglAQYHxqp3zldeca8UkxmdJfZmOXu39YE6bwmccUkh8Xp3tCKRHVLjiHuESDGAYTI30V7bvt6m25x4NPVLhPIU9SsMw3E3XhEd27jaw+fSM0Z++QtBFX5nIzaMmc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731061959; c=relaxed/simple; bh=Y1DchAs7VMC2A3AGrg36PWB96mQ+5c2bZIG4uYsYJGI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=AA3SlFgbgQcVYU+XBBBNBHVSL1IQri5vtRwaOsczu2Q8Mq71ODD1OQwXzooO4Yz1XoI+gJgByIJUtWJmpQuOVSE1310AlD4CYb4shf3OWKVEZaCHRwsSjju1YJL9pIAiZu/OuxfoF+N2ZMwuVZ9JilU93X08Pq4DOwwRI2w9IB8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jw6VeM7M; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="jw6VeM7M" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 99DE6C4AF49; Fri, 8 Nov 2024 10:32:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1731061958; bh=Y1DchAs7VMC2A3AGrg36PWB96mQ+5c2bZIG4uYsYJGI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jw6VeM7MaoKm+BRhRuHk3uLHXcMx10Mp43ZXO8qkVP07TcVCTGaaKCCf1ISwKQF+E ODf8D5xssLYaBDXUmqde42crwmLhEN4FwkeWH0HFoD6jk4r0WXjv6NkGusQQY86P5z cooUnndltc6JqeV9A1WrmJACVsETpoOl2+rJx/uZ3zOMHqXjr2MWS7dhUYI2qIVHIl UqxrRWAV/AmdfgARnJvMhDGuf9viIVi57RRSwNGeFMygGoKm7EmqMu0ONkoVXP2H0J dIEg1K6q8VZxXHnRSguReDmSdElq5qwCuacw4DLT0U3OGArQpEGo26cjXGwdK12BQZ aFZWVfmb4ZbwA== Received: from johan by xi.lan with local (Exim 4.97.1) (envelope-from ) id 1t9MIC-0000000081z-29in; Fri, 08 Nov 2024 11:32:40 +0100 Date: Fri, 8 Nov 2024 11:32:40 +0100 From: Johan Hovold To: Chris Lew Cc: Manivannan Sadhasivam , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Hemant Kumar , Loic Poulain , Maxim Kochetkov , Manivannan Sadhasivam , Bjorn Andersson , linux-arm-msm@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Bhaumik Bhatt Subject: Re: [PATCH] net: qrtr: mhi: synchronize qrtr and mhi preparation Message-ID: References: <20241104-qrtr_mhi-v1-1-79adf7e3bba5@quicinc.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241104-qrtr_mhi-v1-1-79adf7e3bba5@quicinc.com> On Mon, Nov 04, 2024 at 05:29:37PM -0800, Chris Lew wrote: > From: Bhaumik Bhatt > > The call to qrtr_endpoint_register() was moved before > mhi_prepare_for_transfer_autoqueue() to prevent a case where a dl > callback can occur before the qrtr endpoint is registered. > > Now 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: 68a838b84eff ("net: qrtr: start MHI channel after endpoit creation") > Reported-by: Johan Hovold > Closes: https://lore.kernel.org/linux-arm-msm/ZyTtVdkCCES0lkl4@hovoldconsulting.com/ > Signed-off-by: Bhaumik Bhatt > Signed-off-by: Chris Lew > @@ -53,6 +54,10 @@ static int qcom_mhi_qrtr_send(struct qrtr_endpoint *ep, struct sk_buff *skb) > if (skb->sk) > sock_hold(skb->sk); > > + rc = wait_for_completion_interruptible(&qdev->prepared); > + if (rc) > + goto free_skb; > + > rc = skb_linearize(skb); > if (rc) > goto free_skb; > @@ -85,6 +90,7 @@ 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->prepared); > > dev_set_drvdata(&mhi_dev->dev, qdev); > rc = qrtr_endpoint_register(&qdev->ep, QRTR_EP_NID_AUTO); > @@ -97,6 +103,7 @@ static int qcom_mhi_qrtr_probe(struct mhi_device *mhi_dev, > qrtr_endpoint_unregister(&qdev->ep); > return rc; > } > + complete_all(&qdev->prepared); > > dev_dbg(qdev->dev, "Qualcomm MHI QRTR driver probed\n"); While this probably works, it still looks like a bit of a hack. Why can't you restructure the code so that the channels are fully initialised before you register or enable them instead? Johan