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 08BA3C678D4 for ; Tue, 17 Jan 2023 13:59:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230418AbjAQN7G (ORCPT ); Tue, 17 Jan 2023 08:59:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52624 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231962AbjAQN6i (ORCPT ); Tue, 17 Jan 2023 08:58:38 -0500 Received: from mail-wr1-x432.google.com (mail-wr1-x432.google.com [IPv6:2a00:1450:4864:20::432]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2E07D14EB4 for ; Tue, 17 Jan 2023 05:58:30 -0800 (PST) Received: by mail-wr1-x432.google.com with SMTP id h16so30653704wrz.12 for ; Tue, 17 Jan 2023 05:58:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :from:to:cc:subject:date:message-id:reply-to; bh=ko9Au63T5jQD1W8bikN9mMCHcytumVvcya0Oe8Eicbg=; b=Kob2MhDYec2Ei3hdYCTd/Vv8zLzCzgSCWLUK3e2lGxNTiIrSgg23+DIH5gDVZNnG1S 3gd9iXF/LoqqsHvopx9+Mv9KrHHLQi995wvmlxMpo//Vg63X6VBg5Mha3lx/DTWSAFB0 IBQK6ETJC2Eng73cJsXu8mWMBMII7cHREyPhZQGrburhtnpUNNfDbiwaAMK9FnSWY4d3 6YBCrMloJFthRdkUb2nYcgOwW+18NcawPhLsB+AjW+ASA4QTeA54qCjRgCw3ZA4u0oqf czHLS1ewpR3jZSj2LR4/wbtWb2J0h3HalAalAbeDn0WvepFt4kV/Rbi7lFiY/0iryNY3 Lksg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=ko9Au63T5jQD1W8bikN9mMCHcytumVvcya0Oe8Eicbg=; b=KxcSZH8zNFSbTBbERiikzBdjMzs1fkP8nTeE657SLkyaf/4kMJy3qHc8GYZRfKvWh+ fhIz6FtBxa9HLcmNOmyB2Vpdbqw0hH2YDerRVxFZnK9Np1qASu4hd8JzkI4Zhxfj0xzg jMmZvpVbyw7287VhnSplraaHlELDmrkq9pDonwoUzqYAMVr68bsgRHJrfai0IlFWfYQ1 fMpOM9uC+qll704AR/WUpIRrYPguuUUgMhq+4aHQLk7Mn3ULoGv1BXZ1UO+XFZ7IQG3h eDxpJjME4LcP6cd4xCzqPuMRLQ9KlwggbQoRHm4L5UZgUW74Lj7qjMiGQbnE0CuJWCcb 0RQg== X-Gm-Message-State: AFqh2kodFiNt04rO7Qkb7vKwpGMdgSe7N6oZOiv2J2Q9ywv+OeQeRZul q4KI66R2iZ7yIL3oU1cF9M8= X-Google-Smtp-Source: AMrXdXvFUkBiwSHWkje1Ft9rEwXpUqAGRGJM1be982uNGwnlP8TWQ1rN0yr+YnuZLhcH0UIimZcNyw== X-Received: by 2002:adf:fa43:0:b0:2bd:c225:1fe8 with SMTP id y3-20020adffa43000000b002bdc2251fe8mr3249737wrr.14.1673963908732; Tue, 17 Jan 2023 05:58:28 -0800 (PST) Received: from localhost ([102.36.222.112]) by smtp.gmail.com with ESMTPSA id i6-20020adfe486000000b002423dc3b1a9sm28398888wrm.52.2023.01.17.05.58.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 17 Jan 2023 05:58:27 -0800 (PST) Date: Tue, 17 Jan 2023 16:58:12 +0300 From: Dan Carpenter To: atenart@kernel.org Cc: linux-clk@vger.kernel.org Subject: [bug report] net: macb: convert to phylink Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org Hello Antoine Tenart, The patch 7897b071ac3b: "net: macb: convert to phylink" from Nov 13, 2019, leads to the following Smatch static checker warning: drivers/clk/clk.c:133 clk_prepare_lock() warn: sleeping in atomic context drivers/clk/clk.c 126 static void clk_prepare_lock(void) 127 { 128 if (!mutex_trylock(&prepare_lock)) { 129 if (prepare_owner == current) { 130 prepare_refcnt++; 131 return; 132 } --> 133 mutex_lock(&prepare_lock); 134 } 135 WARN_ON_ONCE(prepare_owner != NULL); 136 WARN_ON_ONCE(prepare_refcnt != 0); 137 prepare_owner = current; 138 prepare_refcnt = 1; 139 } The problem is that cadence/macb_main calls clk_set_rate() while holding a spinlock. The call tree is: owl_uart_set_termios() <- disables preempt -> owl_uart_change_baudrate() rda_uart_set_termios() <- disables preempt -> rda_uart_change_baudrate() atmel_set_termios() <- disables preempt macb_mac_link_up() <- disables preempt (THIS ONE) -> macb_set_tx_clk() -> clk_set_rate() -> clk_prepare_lock() drivers/net/ethernet/cadence/macb_main.c 666 static void macb_mac_link_up(struct phylink_config *config, 667 struct phy_device *phy, 668 unsigned int mode, phy_interface_t interface, 669 int speed, int duplex, 670 bool tx_pause, bool rx_pause) 671 { 672 struct net_device *ndev = to_net_dev(config->dev); 673 struct macb *bp = netdev_priv(ndev); 674 struct macb_queue *queue; 675 unsigned long flags; 676 unsigned int q; 677 u32 ctrl; 678 679 spin_lock_irqsave(&bp->lock, flags); ^^^^^^^^^^^^^^^^^ Spin lock. 680 681 ctrl = macb_or_gem_readl(bp, NCFGR); 682 683 ctrl &= ~(MACB_BIT(SPD) | MACB_BIT(FD)); 684 685 if (speed == SPEED_100) 686 ctrl |= MACB_BIT(SPD); 687 688 if (duplex) 689 ctrl |= MACB_BIT(FD); 690 691 if (!(bp->caps & MACB_CAPS_MACB_IS_EMAC)) { 692 ctrl &= ~MACB_BIT(PAE); 693 if (macb_is_gem(bp)) { 694 ctrl &= ~GEM_BIT(GBE); 695 696 if (speed == SPEED_1000) 697 ctrl |= GEM_BIT(GBE); 698 } 699 700 if (rx_pause) 701 ctrl |= MACB_BIT(PAE); 702 703 macb_set_tx_clk(bp, speed); ^^^^^^^^^^^^^^^^^^^^^^^^^^^ Takes a mutex. 704 705 /* Initialize rings & buffers as clearing MACB_BIT(TE) in link down 706 * cleared the pipeline and control registers. 707 */ 708 bp->macbgem_ops.mog_init_rings(bp); 709 macb_init_buffers(bp); regards, dan carpenter