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=-17.6 required=3.0 tests=DKIMWL_WL_MED,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_GIT, USER_IN_DEF_DKIM_WL 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 1FA20C433E0 for ; Wed, 1 Jul 2020 19:43:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E4CDE208B6 for ; Wed, 1 Jul 2020 19:43:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="WyQ7OotS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727052AbgGATnP (ORCPT ); Wed, 1 Jul 2020 15:43:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43074 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726897AbgGATnN (ORCPT ); Wed, 1 Jul 2020 15:43:13 -0400 Received: from mail-qt1-x84a.google.com (mail-qt1-x84a.google.com [IPv6:2607:f8b0:4864:20::84a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 14C8AC08C5C1 for ; Wed, 1 Jul 2020 12:43:13 -0700 (PDT) Received: by mail-qt1-x84a.google.com with SMTP id 94so17221566qtb.21 for ; Wed, 01 Jul 2020 12:43:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=RNo7BV5Oou7hkj/VlWeebNh0BIZznccS6eLAmKTw21I=; b=WyQ7OotSF738GXLwDI0AZXkknc4DpNr5GZpPUpTN9wSe1Ok6OG3iUT7SifouDzp7iL OOCxXZMScXvO1Zgu9VgQ6KZxYoaTXixClsluL3heSghrh0LQ5hXs6+lesForYZ4YESlh 6GIP1CxlNj9GrtDWx4yJ4RhgFJC2+asg3ZoSe1G8myKawONTWcsyHOtl+zrMWsJebDmL l6/CjTmnJGwzugUbbCqalTl6E6UhpcKaKGLtklTMpEF5EIcTTCho3qfiSRFEgb7iQTAK 2lOVYSGCJ5IWLsz6qqKtrIqEYeA/0gBVN6+b25I+ikykR7A3nKiQ+e1AJNmLEoDeCjZs HHHw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=RNo7BV5Oou7hkj/VlWeebNh0BIZznccS6eLAmKTw21I=; b=kyJpIb5ArSavm+dQEtQfjNLfdr3ovwsrQExzKRqSBIxqqagl5D91aJxsKrlS+GEV/k RjW9QCwG6eIqRiB0KpMmAXyftw0qmaHXrDsb9EwG1Q01xRDD3WbRUdcACY/pmdpCDdjV wCfiDNPOFNy6n1pPnRp3SOPQ68Kwu0ka9gpz7ePVua96rJuy/cIrI/uYFzJLjq78LMl9 2qRQMrBlptcTiW41BvtvYRcytrOJvC+TjfQJPu6rQZFX3X6CZM06hpOM0nCRfdy+ahGg 5QEnJ7FBssFfZpit3CtdRZFTJ0Kaf/lCBMbJugK0jY5ciiYenfUOKpZzIW22Eyo3Scld wLRA== X-Gm-Message-State: AOAM531w3wvv6mMGek87ue5OqMAi2+Hg5oBZkcKG25z87jgvY6FPZHpT A+cAGVzOu0y2TKaZcIf/lvXM430eJtut9VY= X-Google-Smtp-Source: ABdhPJw1ENNKo02v+Etu3anTvX9igMA3mFZCj36ThlNIJPiDecxKWeubGSH+NOUsFiu70H72Ou/MGTidiUp3VIE= X-Received: by 2002:a0c:d687:: with SMTP id k7mr19362642qvi.42.1593632592297; Wed, 01 Jul 2020 12:43:12 -0700 (PDT) Date: Wed, 1 Jul 2020 12:42:59 -0700 In-Reply-To: <20200701194259.3337652-1-saravanak@google.com> Message-Id: <20200701194259.3337652-4-saravanak@google.com> Mime-Version: 1.0 References: <20200701194259.3337652-1-saravanak@google.com> X-Mailer: git-send-email 2.27.0.212.ge8ba1cc988-goog Subject: [PATCH v1 3/3] driver core: Avoid deferred probe due to fw_devlink_pause/resume() From: Saravana Kannan To: Greg Kroah-Hartman , "Rafael J. Wysocki" , Saravana Kannan Cc: linux-kernel@vger.kernel.org, Geert Uytterhoeven , kernel-team@android.com Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org With the earlier patch in this series, all devices that deferred probe due to fw_devlink_pause() will have their probes delayed till the deferred probe thread is kicked off during late_initcall. This will also affect all their consumers. This delayed probing in unnecessary. So this patch just keeps track of the devices that had their probe deferred due to fw_devlink_pause() and attempts to probe them once during fw_devlink_resume(). Fixes: 716a7a259690 ("driver core: fw_devlink: Add support for batching fwnode parsing") Signed-off-by: Saravana Kannan --- drivers/base/core.c | 21 +++++++++++++++++++++ include/linux/device.h | 3 ++- 2 files changed, 23 insertions(+), 1 deletion(-) diff --git a/drivers/base/core.c b/drivers/base/core.c index d1d2cdc3a8d8..05d414e9e8a4 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -50,6 +50,7 @@ static DEFINE_MUTEX(wfs_lock); static LIST_HEAD(deferred_sync); static unsigned int defer_sync_state_count = 1; static unsigned int defer_fw_devlink_count; +static LIST_HEAD(deferred_fw_devlink); static DEFINE_MUTEX(defer_fw_devlink_lock); static bool fw_devlink_is_permissive(void); @@ -1244,6 +1245,12 @@ static void fw_devlink_link_device(struct device *dev) fw_ret = -EAGAIN; } else { fw_ret = -ENODEV; + /* + * defer_hook is not used to add device to deferred_sync list + * until device is bound. Since deferred fw devlink also blocks + * probing, same list hook can be used for deferred_fw_devlink. + */ + list_add_tail(&dev->links.defer_hook, &deferred_fw_devlink); } if (fw_ret == -ENODEV) @@ -1312,6 +1319,9 @@ void fw_devlink_pause(void) */ void fw_devlink_resume(void) { + struct device *dev, *tmp; + LIST_HEAD(probe_list); + mutex_lock(&defer_fw_devlink_lock); if (!defer_fw_devlink_count) { WARN(true, "Unmatched fw_devlink pause/resume!"); @@ -1323,8 +1333,19 @@ void fw_devlink_resume(void) goto out; device_link_add_missing_supplier_links(); + list_splice_tail_init(&deferred_fw_devlink, &probe_list); out: mutex_unlock(&defer_fw_devlink_lock); + + /* + * bus_probe_device() can cause new devices to get added and they'll + * try to grab defer_fw_devlink_lock. So, this needs to be done outside + * the defer_fw_devlink_lock. + */ + list_for_each_entry_safe(dev, tmp, &probe_list, links.defer_hook) { + list_del_init(&dev->links.defer_hook); + bus_probe_device(dev); + } } /* Device links support end. */ diff --git a/include/linux/device.h b/include/linux/device.h index 9bb2bc7bb8e3..5efed864b387 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -433,7 +433,8 @@ enum dl_dev_state { * @suppliers: List of links to supplier devices. * @consumers: List of links to consumer devices. * @needs_suppliers: Hook to global list of devices waiting for suppliers. - * @defer_hook: Hook to global list of devices that have deferred sync_state. + * @defer_hook: Hook to global list of devices that have deferred sync_state or + * deferred fw_devlink. * @need_for_probe: If needs_suppliers is on a list, this indicates if the * suppliers are needed for probe or not. * @status: Driver status information. -- 2.27.0.212.ge8ba1cc988-goog