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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 78136C4332F for ; Mon, 5 Dec 2022 16:58:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230295AbiLEQ6p (ORCPT ); Mon, 5 Dec 2022 11:58:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56836 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230254AbiLEQ6n (ORCPT ); Mon, 5 Dec 2022 11:58:43 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E2E56C774 for ; Mon, 5 Dec 2022 08:58:42 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 9AB67B81185 for ; Mon, 5 Dec 2022 16:58:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 79BC7C433D6; Mon, 5 Dec 2022 16:58:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1670259520; bh=7EV0jXWy9hOf/Ucrpiiq1MKM0P0LmE+diFld3cktmiQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=VxWXHy1MF/y8NQI+fNioD1ikZJ+GqVG0pvkrscgNP9CYeJH6A5MDhC1RfHlvwiJtt 6H7zakG3lBi1smYxKz5MMgvPNRIuNNZdVvcYKigRS58NoU1/wWpJ+Ra+R7C6agPDBO rpgYXETaK7byh7hWSi8c8Ob29bhmPke1utY/2soJGCUr9eBxQrZ20VQ3UXmD8b4ILC xlYghf7kwL/DG2/WU5iFWGXBy7a6fZ8mfzP3EZAwl5T3+vt8u6ZY4ovNM4qtqcxhD/ LIwRjhkG+aC4f//xuVWoyAIT/QRYy2nsg7TJrBpY2otDRF7TgriJw9jJUHGOxPMKjs 7jq+igAxJusVg== Date: Mon, 5 Dec 2022 18:58:35 +0200 From: Leon Romanovsky To: Lorenzo Bianconi Cc: netdev@vger.kernel.org, nbd@nbd.name, john@phrozen.org, sean.wang@mediatek.com, Mark-MC.Lee@mediatek.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, matthias.bgg@gmail.com, linux-mediatek@lists.infradead.org, lorenzo.bianconi@redhat.com, sujuan.chen@mediatek.com Subject: Re: [PATCH v2 net-next] net: ethernet: mtk_wed: fix possible deadlock if mtk_wed_wo_init fails Message-ID: References: <5a29aae6c4a26e807844210d4ddac7950ca5f63d.1670238731.git.lorenzo@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5a29aae6c4a26e807844210d4ddac7950ca5f63d.1670238731.git.lorenzo@kernel.org> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, Dec 05, 2022 at 12:14:41PM +0100, Lorenzo Bianconi wrote: > Introduce __mtk_wed_detach() in order to avoid a possible deadlock in > mtk_wed_attach routine if mtk_wed_wo_init fails. > Check wo pointer is properly allocated before running mtk_wed_wo_reset() > and mtk_wed_wo_deinit() in __mtk_wed_detach routine. > Honor mtk_wed_mcu_send_msg return value in mtk_wed_wo_reset(). > > Fixes: 4c5de09eb0d0 ("net: ethernet: mtk_wed: add configure wed wo support") > Signed-off-by: Lorenzo Bianconi > --- > Changes since v1: > - move wo pointer checks in __mtk_wed_detach() > --- > drivers/net/ethernet/mediatek/mtk_wed.c | 30 ++++++++++++++------- > drivers/net/ethernet/mediatek/mtk_wed_mcu.c | 3 +++ > 2 files changed, 23 insertions(+), 10 deletions(-) > > diff --git a/drivers/net/ethernet/mediatek/mtk_wed.c b/drivers/net/ethernet/mediatek/mtk_wed.c > index d041615b2bac..2ce9fbb1c66d 100644 > --- a/drivers/net/ethernet/mediatek/mtk_wed.c > +++ b/drivers/net/ethernet/mediatek/mtk_wed.c > @@ -174,9 +174,10 @@ mtk_wed_wo_reset(struct mtk_wed_device *dev) > mtk_wdma_tx_reset(dev); > mtk_wed_reset(dev, MTK_WED_RESET_WED); > > - mtk_wed_mcu_send_msg(wo, MTK_WED_MODULE_ID_WO, > - MTK_WED_WO_CMD_CHANGE_STATE, &state, > - sizeof(state), false); > + if (mtk_wed_mcu_send_msg(wo, MTK_WED_MODULE_ID_WO, > + MTK_WED_WO_CMD_CHANGE_STATE, &state, > + sizeof(state), false)) > + return; > > if (readx_poll_timeout(mtk_wed_wo_read_status, dev, val, > val == MTK_WED_WOIF_DISABLE_DONE, > @@ -576,12 +577,10 @@ mtk_wed_deinit(struct mtk_wed_device *dev) > } > > static void > -mtk_wed_detach(struct mtk_wed_device *dev) > +__mtk_wed_detach(struct mtk_wed_device *dev) > { > struct mtk_wed_hw *hw = dev->hw; > > - mutex_lock(&hw_lock); > - > mtk_wed_deinit(dev); > > mtk_wdma_rx_reset(dev); > @@ -590,9 +589,11 @@ mtk_wed_detach(struct mtk_wed_device *dev) > mtk_wed_free_tx_rings(dev); > > if (mtk_wed_get_rx_capa(dev)) { > - mtk_wed_wo_reset(dev); > + if (hw->wed_wo) > + mtk_wed_wo_reset(dev); > mtk_wed_free_rx_rings(dev); > - mtk_wed_wo_deinit(hw); > + if (hw->wed_wo) > + mtk_wed_wo_deinit(hw); > } > > if (dev->wlan.bus_type == MTK_WED_BUS_PCIE) { > @@ -612,6 +613,13 @@ mtk_wed_detach(struct mtk_wed_device *dev) > module_put(THIS_MODULE); > > hw->wed_dev = NULL; > +} > + > +static void > +mtk_wed_detach(struct mtk_wed_device *dev) > +{ > + mutex_lock(&hw_lock); > + __mtk_wed_detach(dev); > mutex_unlock(&hw_lock); > } > > @@ -1490,8 +1498,10 @@ mtk_wed_attach(struct mtk_wed_device *dev) > ret = mtk_wed_wo_init(hw); > } > out: > - if (ret) > - mtk_wed_detach(dev); > + if (ret) { > + dev_err(dev->hw->dev, "failed to attach wed device\n"); > + __mtk_wed_detach(dev); > + } > unlock: > mutex_unlock(&hw_lock); > > diff --git a/drivers/net/ethernet/mediatek/mtk_wed_mcu.c b/drivers/net/ethernet/mediatek/mtk_wed_mcu.c > index f9539e6233c9..3dd02889d972 100644 > --- a/drivers/net/ethernet/mediatek/mtk_wed_mcu.c > +++ b/drivers/net/ethernet/mediatek/mtk_wed_mcu.c > @@ -207,6 +207,9 @@ int mtk_wed_mcu_msg_update(struct mtk_wed_device *dev, int id, void *data, > if (dev->hw->version == 1) > return 0; > > + if (!wo) > + return -ENODEV; > + Can you please help me to understand how and when this mtk_wed_mcu_msg_update() function is called? I see this line .msg_update = mtk_wed_mcu_msg_update, and relevant mtk_wed_device_update_msg() define, but nothing calls to this define. > return mtk_wed_mcu_send_msg(wo, MTK_WED_MODULE_ID_WO, id, data, len, > true); > } > -- > 2.38.1 >