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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A74F6C433F5 for ; Mon, 18 Oct 2021 13:46:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 917C2610C7 for ; Mon, 18 Oct 2021 13:46:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233839AbhJRNsM (ORCPT ); Mon, 18 Oct 2021 09:48:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:39220 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233759AbhJRNpu (ORCPT ); Mon, 18 Oct 2021 09:45:50 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 52050613B1; Mon, 18 Oct 2021 13:35:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1634564146; bh=hBd9iOYLrMj0XoiqnTOeQaYnQhZSOFQG7P3M9m2RdBM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GAdgVqCq2WWIAZgVDcd/0kdEbS4K6hX0pzw3QTayfEcOpnbX8L9DaDDolJo+B6MTm b3Zq2AVNqvWp2X9BIikks2VAtqLyEUtjCbvsvBJt9wTQAesfo6WKrr8/sX0shoB8nD IlPZLsd9wL5+6CsLX/6XizuXeiRSRG/OrDOrR+GY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Rob Herring , Saravana Kannan , Ulf Hansson , Geert Uytterhoeven , Damien Le Moal Subject: [PATCH 5.10 049/103] drivers: bus: simple-pm-bus: Add support for probing simple bus only devices Date: Mon, 18 Oct 2021 15:24:25 +0200 Message-Id: <20211018132336.396908614@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211018132334.702559133@linuxfoundation.org> References: <20211018132334.702559133@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: linux-kernel@vger.kernel.org From: Saravana Kannan commit 98e96cf80045a383fcc47c58dd4e87b3ae587b3e upstream. fw_devlink could end up creating device links for bus only devices. However, bus only devices don't get probed and can block probe() or sync_state() [1] call backs of other devices. To avoid this, probe these devices using the simple-pm-bus driver. However, there are instances of devices that are not simple buses (they get probed by their specific drivers) that also list the "simple-bus" (or other bus only compatible strings) in their compatible property to automatically populate their child devices. We still want these devices to get probed by their specific drivers. So, we make sure this driver only probes devices that are only buses. [1] - https://lore.kernel.org/lkml/CAPDyKFo9Bxremkb1dDrr4OcXSpE0keVze94Cm=zrkOVxHHxBmQ@mail.gmail.com/ Fixes: c442a0d18744 ("driver core: Set fw_devlink to "permissive" behavior by default") Cc: stable Cc: Rob Herring Tested-by: Saravana Kannan Tested-by: Ulf Hansson Tested-by: Geert Uytterhoeven Tested-by: Damien Le Moal Signed-off-by: Saravana Kannan Link: https://lore.kernel.org/r/20210929000735.585237-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman --- drivers/bus/simple-pm-bus.c | 39 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 38 insertions(+), 1 deletion(-) --- a/drivers/bus/simple-pm-bus.c +++ b/drivers/bus/simple-pm-bus.c @@ -16,7 +16,33 @@ static int simple_pm_bus_probe(struct platform_device *pdev) { - struct device_node *np = pdev->dev.of_node; + const struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + const struct of_device_id *match; + + /* + * Allow user to use driver_override to bind this driver to a + * transparent bus device which has a different compatible string + * that's not listed in simple_pm_bus_of_match. We don't want to do any + * of the simple-pm-bus tasks for these devices, so return early. + */ + if (pdev->driver_override) + return 0; + + match = of_match_device(dev->driver->of_match_table, dev); + /* + * These are transparent bus devices (not simple-pm-bus matches) that + * have their child nodes populated automatically. So, don't need to + * do anything more. We only match with the device if this driver is + * the most specific match because we don't want to incorrectly bind to + * a device that has a more specific driver. + */ + if (match && match->data) { + if (of_property_match_string(np, "compatible", match->compatible) == 0) + return 0; + else + return -ENODEV; + } dev_dbg(&pdev->dev, "%s\n", __func__); @@ -30,14 +56,25 @@ static int simple_pm_bus_probe(struct pl static int simple_pm_bus_remove(struct platform_device *pdev) { + const void *data = of_device_get_match_data(&pdev->dev); + + if (pdev->driver_override || data) + return 0; + dev_dbg(&pdev->dev, "%s\n", __func__); pm_runtime_disable(&pdev->dev); return 0; } +#define ONLY_BUS ((void *) 1) /* Match if the device is only a bus. */ + static const struct of_device_id simple_pm_bus_of_match[] = { { .compatible = "simple-pm-bus", }, + { .compatible = "simple-bus", .data = ONLY_BUS }, + { .compatible = "simple-mfd", .data = ONLY_BUS }, + { .compatible = "isa", .data = ONLY_BUS }, + { .compatible = "arm,amba-bus", .data = ONLY_BUS }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, simple_pm_bus_of_match);