From patchwork Mon Apr 13 20:42:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Stultz X-Patchwork-Id: 185378 Delivered-To: patches@linaro.org Received: by 2002:a92:3d9a:0:0:0:0:0 with SMTP id k26csp650542ilf; Mon, 13 Apr 2020 13:43:05 -0700 (PDT) X-Received: by 2002:a17:90a:fa08:: with SMTP id cm8mr23701934pjb.144.1586810585090; Mon, 13 Apr 2020 13:43:05 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1586810585; cv=none; d=google.com; s=arc-20160816; b=mlJ8kvu1oHOARTCJDbyJfRlCJsdSOnLgf5yIpwMSEcGBBebKz57Mi3mwncJohHgF4s 8UnXhx53Tyy5Eb00K3y2UT6bJxGD1Jut2M5MaKOXDtR2LgpJGVidr+jqre5v06WQiGs/ x1ipJXe+O7wA10HOpDa06V45IeM8pqZlFN8mkASf7P2sr1Gzjk6v+k730y0vV/ygDki5 +t9eeQJM/m0axnzuIZR5F+3JxYbP1R9f476Y7BDDLGdNMek4s603WKqSHb0fcSf2oI9e MIY1T5r1c7RhZF2RbSv1MUm0TQClV5leUVV/uZtJXGsbMm32bmPVV53Ob5AdkjaN/NX7 FYRA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=qou+3DHiFyCOtLsGQReefr67dF1uugnjJ0cGHULWluA=; b=n9U0KMElhXT+Ue4MeFOhFcImTcUwG3Fw6aI/q3js9atUTYHYtsRIafwk+IhQb7FdYK oNI7JG/mO5Qw3ojd8+VmQ+vFvznwUFD/a+7BT2toYwun1Vpyj22onty4n0214H9k508P ssLh//pJEC3zk1+cJL2mepGC8jl1x5KxQ0+U85YFpaMQ29ydaal0M7jVxh+ISGgHW4iE F9V8RBa1+cpRAwCpzkQbO4mltWC/nVqYfTwdnJZ6zYVkK1Lt3rl1W2HfOmZt5HBi9+/k IJzzDmNuI63KRslVy1jJIL+y3bWIn1HKvHMvZAJAugw1uGSjQk1MTu3XLy6+qzNU+Udk Ae1Q== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=coykwgBI; spf=pass (google.com: domain of john.stultz@linaro.org designates 209.85.220.65 as permitted sender) smtp.mailfrom=john.stultz@linaro.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Return-Path: Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. 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Miller" , Alexey Kuznetsov , Hideaki YOSHIFUJI , Jakub Kicinski , Greg Kroah-Hartman , "Rafael J . Wysocki" , Rob Herring , Geert Uytterhoeven , Yoshihiro Shimoda , netdev , linux-pm@vger.kernel.org Subject: [PATCH v2 1/2] driver core: Revert default driver_deferred_probe_timeout value to 0 Date: Mon, 13 Apr 2020 20:42:52 +0000 Message-Id: <20200413204253.84991-2-john.stultz@linaro.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200413204253.84991-1-john.stultz@linaro.org> References: <20200413204253.84991-1-john.stultz@linaro.org> In commit c8c43cee29f6 ("driver core: Fix driver_deferred_probe_check_state() logic"), we both cleaned up the logic and also set the default driver_deferred_probe_timeout value to 30 seconds to allow for drivers that are missing dependencies to have some time so that the dependency may be loaded from userland after initcalls_done is set. However, Yoshihiro Shimoda reported that on his device that expects to have unmet dependencies (due to "optional links" in its devicetree), was failing to mount the NFS root. In digging further, it seemed the problem was that while the device properly probes after waiting 30 seconds for any missing modules to load, the ip_auto_config() had already failed, resulting in NFS to fail. This was due to ip_auto_config() calling wait_for_device_probe() which doesn't wait for the driver_deferred_probe_timeout to fire. Fixing that issue is possible, but could also introduce 30 second delays in bootups for users who don't have any missing dependencies, which is not ideal. So I think the best solution to avoid any regressions is to revert back to a default timeout value of zero, and allow systems that need to utilize the timeout in order for userland to load any modules that supply misisng dependencies in the dts to specify the timeout length via the exiting documented boot argument. Thanks to Geert for chasing down that ip_auto_config was why NFS was failing in this case! Cc: "David S. Miller" Cc: Alexey Kuznetsov Cc: Hideaki YOSHIFUJI Cc: Jakub Kicinski Cc: Greg Kroah-Hartman Cc: Rafael J. Wysocki Cc: Rob Herring Cc: Geert Uytterhoeven Cc: Yoshihiro Shimoda Cc: netdev Cc: linux-pm@vger.kernel.org Reported-by: Yoshihiro Shimoda Tested-by: Yoshihiro Shimoda Fixes: c8c43cee29f6 ("driver core: Fix driver_deferred_probe_check_state() logic") Signed-off-by: John Stultz --- drivers/base/dd.c | 13 ++----------- 1 file changed, 2 insertions(+), 11 deletions(-) -- 2.17.1 diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 06ec0e851fa1..908ae4d7805e 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -224,16 +224,7 @@ static int deferred_devs_show(struct seq_file *s, void *data) } DEFINE_SHOW_ATTRIBUTE(deferred_devs); -#ifdef CONFIG_MODULES -/* - * In the case of modules, set the default probe timeout to - * 30 seconds to give userland some time to load needed modules - */ -int driver_deferred_probe_timeout = 30; -#else -/* In the case of !modules, no probe timeout needed */ -int driver_deferred_probe_timeout = -1; -#endif +int driver_deferred_probe_timeout; EXPORT_SYMBOL_GPL(driver_deferred_probe_timeout); static int __init deferred_probe_timeout_setup(char *str) @@ -266,7 +257,7 @@ int driver_deferred_probe_check_state(struct device *dev) return -ENODEV; } - if (!driver_deferred_probe_timeout) { + if (!driver_deferred_probe_timeout && initcalls_done) { dev_WARN(dev, "deferred probe timeout, ignoring dependency"); return -ETIMEDOUT; }