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=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 C2138C0044D for ; Mon, 16 Mar 2020 07:20:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 95A1120663 for ; Mon, 16 Mar 2020 07:20:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="cThaAhey" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729455AbgCPHUr (ORCPT ); Mon, 16 Mar 2020 03:20:47 -0400 Received: from fllv0015.ext.ti.com ([198.47.19.141]:33044 "EHLO fllv0015.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728120AbgCPHUr (ORCPT ); Mon, 16 Mar 2020 03:20:47 -0400 Received: from lelv0266.itg.ti.com ([10.180.67.225]) by fllv0015.ext.ti.com (8.15.2/8.15.2) with ESMTP id 02G7KhLg012845; Mon, 16 Mar 2020 02:20:43 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1584343243; bh=Yisa4qZBXogsjsu0UBUCrwgSHPoybqOn38y9aI+oMAQ=; h=Subject:To:CC:References:From:Date:In-Reply-To; b=cThaAheyHJ+EAotUZu9KeHnIO+DWyRdUTC6rVjqSrE+ScMlFRGn3F4x2XRkXJQABq EdHCiLd6GigEA84MMDEwswrCIaWRitdgsaOB6XsqE7qmDBa/ImOgzwqQvR06O8HnwY SR65BEC+q7sTETLFTR+Q66jbuoYtIDZed9oT9RE0= Received: from DLEE112.ent.ti.com (dlee112.ent.ti.com [157.170.170.23]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 02G7KhTi112724 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 16 Mar 2020 02:20:43 -0500 Received: from DLEE113.ent.ti.com (157.170.170.24) by DLEE112.ent.ti.com (157.170.170.23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3; Mon, 16 Mar 2020 02:20:42 -0500 Received: from lelv0327.itg.ti.com (10.180.67.183) by DLEE113.ent.ti.com (157.170.170.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3 via Frontend Transport; Mon, 16 Mar 2020 02:20:42 -0500 Received: from [192.168.2.6] (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0327.itg.ti.com (8.15.2/8.15.2) with ESMTP id 02G7KepR117384; Mon, 16 Mar 2020 02:20:41 -0500 Subject: Re: [PATCH] dmaengine: ti: k3-udma: Fix an error handling path in 'k3_udma_glue_cfg_rx_flow()' To: Christophe JAILLET , , , CC: , , References: <20200315155015.27303-1-christophe.jaillet@wanadoo.fr> From: Peter Ujfalusi Message-ID: <49a35126-3cc6-0cbb-e632-42a237ef353e@ti.com> Date: Mon, 16 Mar 2020 09:20:50 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20200315155015.27303-1-christophe.jaillet@wanadoo.fr> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 8bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org Hi Christophe, On 15/03/2020 17.50, Christophe JAILLET wrote: > All but one error handling paths in the 'k3_udma_glue_cfg_rx_flow()' > function 'goto err' and call 'k3_udma_glue_release_rx_flow()'. > > This not correct because this function has a 'channel->flows_ready--;' at > the end, but 'flows_ready' has not been incremented here, when we branch to > the error handling path. > > In order to keep a correct value in 'flows_ready', un-roll > 'k3_udma_glue_release_rx_flow()', simplify it, add some labels and branch > at the correct places when an error is detected. Good catch! > Doing so, we also NULLify 'flow->udma_rflow' in a path that was lacking it. Even better catch ;) > Fixes: d70241913413 ("dmaengine: ti: k3-udma: Add glue layer for non DMAengine user") > Signed-off-by: Christophe JAILLET > --- > Not sure that the last point of the description is correct. Maybe, the > 'xudma_rflow_put / return -ENODEV;' should be kept in order not to > override 'flow->udma_rflow'. > --- > drivers/dma/ti/k3-udma-glue.c | 30 ++++++++++++++++++++---------- > 1 file changed, 20 insertions(+), 10 deletions(-) > > diff --git a/drivers/dma/ti/k3-udma-glue.c b/drivers/dma/ti/k3-udma-glue.c > index dbccdc7c0ed5..890573eb1625 100644 > --- a/drivers/dma/ti/k3-udma-glue.c > +++ b/drivers/dma/ti/k3-udma-glue.c > @@ -578,12 +578,12 @@ static int k3_udma_glue_cfg_rx_flow(struct k3_udma_glue_rx_channel *rx_chn, > if (IS_ERR(flow->udma_rflow)) { > ret = PTR_ERR(flow->udma_rflow); > dev_err(dev, "UDMAX rflow get err %d\n", ret); > - goto err; > + goto err_return; return err; ? > } Optionally you could have moved the rx_chn->flows_ready++; here and > > if (flow->udma_rflow_id != xudma_rflow_get_id(flow->udma_rflow)) { > - xudma_rflow_put(rx_chn->common.udmax, flow->udma_rflow); > - return -ENODEV; > + ret = -ENODEV; > + goto err_rflow_put; goto err; > } > > /* request and cfg rings */ > @@ -592,7 +592,7 @@ static int k3_udma_glue_cfg_rx_flow(struct k3_udma_glue_rx_channel *rx_chn, > if (!flow->ringrx) { > ret = -ENODEV; > dev_err(dev, "Failed to get RX ring\n"); > - goto err; > + goto err_rflow_put; > } > > flow->ringrxfdq = k3_ringacc_request_ring(rx_chn->common.ringacc, > @@ -600,19 +600,19 @@ static int k3_udma_glue_cfg_rx_flow(struct k3_udma_glue_rx_channel *rx_chn, > if (!flow->ringrxfdq) { > ret = -ENODEV; > dev_err(dev, "Failed to get RXFDQ ring\n"); > - goto err; > + goto err_ringrx_free; > } > > ret = k3_ringacc_ring_cfg(flow->ringrx, &flow_cfg->rx_cfg); > if (ret) { > dev_err(dev, "Failed to cfg ringrx %d\n", ret); > - goto err; > + goto err_ringrxfdq_free; > } > > ret = k3_ringacc_ring_cfg(flow->ringrxfdq, &flow_cfg->rxfdq_cfg); > if (ret) { > dev_err(dev, "Failed to cfg ringrxfdq %d\n", ret); > - goto err; > + goto err_ringrxfdq_free; > } > > if (rx_chn->remote) { > @@ -662,7 +662,7 @@ static int k3_udma_glue_cfg_rx_flow(struct k3_udma_glue_rx_channel *rx_chn, > if (ret) { > dev_err(dev, "flow%d config failed: %d\n", flow->udma_rflow_id, > ret); > - goto err; > + goto err_ringrxfdq_free; > } > > rx_chn->flows_ready++; > @@ -670,8 +670,18 @@ static int k3_udma_glue_cfg_rx_flow(struct k3_udma_glue_rx_channel *rx_chn, > flow->udma_rflow_id, rx_chn->flows_ready); > > return 0; > -err: > - k3_udma_glue_release_rx_flow(rx_chn, flow_idx); > + > +err_ringrxfdq_free: > + k3_ringacc_ring_free(flow->ringrxfdq); > + > +err_ringrx_free: > + k3_ringacc_ring_free(flow->ringrx); > + > +err_rflow_put: > + xudma_rflow_put(rx_chn->common.udmax, flow->udma_rflow); > + flow->udma_rflow = NULL; > + > +err_return: You could have kept the single err label and just copy the release_rx_flow() without the rx_chn->flows_ready--; I don't have anything against multiple labels as such, but a single one might be easier to follow? and you don't need the err_return, just return in place when you would jump to it. > return ret; > } > > - Péter Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki