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 1585AC433EF for ; Mon, 18 Apr 2022 12:39:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235616AbiDRMmG (ORCPT ); Mon, 18 Apr 2022 08:42:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40100 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240320AbiDRMix (ORCPT ); Mon, 18 Apr 2022 08:38:53 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2C49324F25; Mon, 18 Apr 2022 05:29:35 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 6A92761033; Mon, 18 Apr 2022 12:29:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 76735C385A1; Mon, 18 Apr 2022 12:29:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1650284973; bh=3GMgtImb+7S5Cm6mxL67P/qzHVn0at/En+PwwCh4UhE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=stGvEdE8M6wTM9YsnQHSpVilK/sEXRLxARh835QybmYLDmU8s1tSHfE5BgQgzsTAP 2nbaoSrJfIwkhlij7DK0WOqv3FsKtn6Toc6VmTa8v66RvKqvgdhpwLVCEMVxbdr9t3 GwP4TVNrD8T2OKApLJsPV2Di6HWvYCqMNfsx5mks= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Robin Murphy , Vladimir Oltean , Florian Fainelli , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15 067/189] net: mdio: dont defer probe forever if PHY IRQ provider is missing Date: Mon, 18 Apr 2022 14:11:27 +0200 Message-Id: <20220418121202.411017860@linuxfoundation.org> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220418121200.312988959@linuxfoundation.org> References: <20220418121200.312988959@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Vladimir Oltean [ Upstream commit 74befa447e6839cdd90ed541159ec783726946f9 ] When a driver for an interrupt controller is missing, of_irq_get() returns -EPROBE_DEFER ad infinitum, causing fwnode_mdiobus_phy_device_register(), and ultimately, the entire of_mdiobus_register() call, to fail. In turn, any phy_connect() call towards a PHY on this MDIO bus will also fail. This is not what is expected to happen, because the PHY library falls back to poll mode when of_irq_get() returns a hard error code, and the MDIO bus, PHY and attached Ethernet controller work fine, albeit suboptimally, when the PHY library polls for link status. However, -EPROBE_DEFER has special handling given the assumption that at some point probe deferral will stop, and the driver for the supplier will kick in and create the IRQ domain. Reasons for which the interrupt controller may be missing: - It is not yet written. This may happen if a more recent DT blob (with an interrupt-parent for the PHY) is used to boot an old kernel where the driver didn't exist, and that kernel worked with the vintage-correct DT blob using poll mode. - It is compiled out. Behavior is the same as above. - It is compiled as a module. The kernel will wait for a number of seconds specified in the "deferred_probe_timeout" boot parameter for user space to load the required module. The current default is 0, which times out at the end of initcalls. It is possible that this might cause regressions unless users adjust this boot parameter. The proposed solution is to use the driver_deferred_probe_check_state() helper function provided by the driver core, which gives up after some -EPROBE_DEFER attempts, taking "deferred_probe_timeout" into consideration. The return code is changed from -EPROBE_DEFER into -ENODEV or -ETIMEDOUT, depending on whether the kernel is compiled with support for modules or not. Fixes: 66bdede495c7 ("of_mdio: Fix broken PHY IRQ in case of probe deferral") Suggested-by: Robin Murphy Signed-off-by: Vladimir Oltean Acked-by: Greg Kroah-Hartman Reviewed-by: Florian Fainelli Link: https://lore.kernel.org/r/20220407165538.4084809-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/base/dd.c | 1 + drivers/net/mdio/fwnode_mdio.c | 5 +++++ 2 files changed, 6 insertions(+) diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 64ce42b6c6b6..95ae347df137 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -296,6 +296,7 @@ int driver_deferred_probe_check_state(struct device *dev) return -EPROBE_DEFER; } +EXPORT_SYMBOL_GPL(driver_deferred_probe_check_state); static void deferred_probe_timeout_work_func(struct work_struct *work) { diff --git a/drivers/net/mdio/fwnode_mdio.c b/drivers/net/mdio/fwnode_mdio.c index 1becb1a731f6..1c1584fca632 100644 --- a/drivers/net/mdio/fwnode_mdio.c +++ b/drivers/net/mdio/fwnode_mdio.c @@ -43,6 +43,11 @@ int fwnode_mdiobus_phy_device_register(struct mii_bus *mdio, int rc; rc = fwnode_irq_get(child, 0); + /* Don't wait forever if the IRQ provider doesn't become available, + * just fall back to poll mode + */ + if (rc == -EPROBE_DEFER) + rc = driver_deferred_probe_check_state(&phy->mdio.dev); if (rc == -EPROBE_DEFER) return rc; -- 2.35.1