From nobody Tue Sep 9 12:16:49 2025 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 82588C678D5 for ; Sat, 4 Mar 2023 00:54:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229808AbjCDAyZ (ORCPT ); Fri, 3 Mar 2023 19:54:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53012 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229665AbjCDAyW (ORCPT ); Fri, 3 Mar 2023 19:54:22 -0500 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E5E6514229 for ; Fri, 3 Mar 2023 16:54:01 -0800 (PST) Received: by mail-yb1-xb49.google.com with SMTP id m6-20020a056902118600b00aeb1e3dbd1bso3984217ybu.9 for ; Fri, 03 Mar 2023 16:54:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; t=1677891241; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=y3KLIsJ5XjymrzajSG4hOMtFPW7EJIs/FRVq4ltjBx8=; b=CpDQBu2btyd5ZDMEYcKgfV0+dPoG2/Nl882vCUbq5opZ/DyGFyvg6w53zwTIq/ArWg OWPfAo61xb4ZGc5534GNyz3TxcZLmENypsmBZ5iRpB9IbgieEjSfO1UFpLVtJnuzsLZf 1G6a+WarDzhoArZtDsEccWBSglPCialIYSXCqzIBRdv12TeoRg/KLpEY0zoK3sdRXLA8 LwpSAfsTL8233bExDD/FJMl4X2IQyous1IRIeXWOsXg4axysyk5ZYa7kwbI6uSu2P/7T dGm07CjSTWYppFAC7lUzwli9C5OCGf2oYksMjFTkNMBZA1hP/15aOGy+qLDDJU4pIX2X 1IDw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1677891241; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=y3KLIsJ5XjymrzajSG4hOMtFPW7EJIs/FRVq4ltjBx8=; b=hL77upGx7RcgUS4bzUxpsHKJ5PDvzfUDuSCU2ADpec8+II5wBv4Mx3M3tDakHiwAhe F53c5UAxRsbGGGfiWhdsVB+DYCrhm/8rfllAZh22r5kKs6WW3fIwxkuTQutKe2pZpqK3 mcCTiqmCZ8z6/RNy8ai3i+4rTeXsrhCED7jkZeOEiGq3symYfC3sMKJwwqTUxoWh65Rb dtttLw1vTFLtWCZfjaKHYHc/cR+GjN+afJ/EW0JY/FM4jqdLLvXA4s7dptOpW2Jq8dkx rtUnevpLZvYmIINxS9i9u7B0SKGi1kyS51h3zdGR9z4Zetd7hBIWehGBarkQoYm1VQK6 mMzg== X-Gm-Message-State: AO0yUKVHaByA5OhB5mpQ1HI8nB1pBbQWvyxPu2L5ht6MJKCM6/abkwfH xTs9eoZdcGV/x2n5nQxtIj3hhzXj0QDfRWU= X-Google-Smtp-Source: AK7set8JH8cdKAM17rBxAnupjfmwqJ9lReTOeCfpxlJKqWEhmnxN9rkv4CScgvpFqicBtVyDeo0xYffqUKOwhxI= X-Received: from saravanak.san.corp.google.com ([2620:15c:2d:3:ef0c:d8be:ebb3:b639]) (user=saravanak job=sendgmr) by 2002:a81:c254:0:b0:52e:e6ed:3089 with SMTP id t20-20020a81c254000000b0052ee6ed3089mr1ywg.521.1677891240787; Fri, 03 Mar 2023 16:54:00 -0800 (PST) Date: Fri, 3 Mar 2023 16:53:53 -0800 In-Reply-To: <20230304005355.746421-1-saravanak@google.com> Message-Id: <20230304005355.746421-2-saravanak@google.com> Mime-Version: 1.0 References: <20230304005355.746421-1-saravanak@google.com> X-Mailer: git-send-email 2.40.0.rc0.216.gc4246ad0f0-goog Subject: [PATCH v2 1/2] driver core: Add fw_devlink.sync_state command line param From: Saravana Kannan To: Jonathan Corbet , Greg Kroah-Hartman , "Rafael J. Wysocki" Cc: Saravana Kannan , Abel Vesa , Bjorn Andersson , Dmitry Baryshkov , Doug Anderson , Matthias Kaehlcke , kernel-team@android.com, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When all devices that could probe have finished probing (based on deferred_probe_timeout configuration or late_initcall() when !CONFIG_MODULES), this parameter controls what to do with devices that haven't yet received their sync_state() calls. fw_devlink.sync_state=3Dstrict is the default and the driver core will continue waiting on all consumers of a device to probe successfully before sync_state() is called for the device. This is the default behavior since calling sync_state() on a device when all its consumers haven't probed could make some systems unusable/unstable. When this option is selected, we also print the list of devices that haven't had sync_state() called on them by the time all devices the could probe have finished probing. fw_devlink.sync_state=3Dtimeout will cause the driver core to give up waiting on consumers and call sync_state() on any devices that haven't yet received their sync_state() calls. This option is provided for systems that won't become unusable/unstable as they might be able to save power (depends on state of hardware before kernel starts) if all devices get their sync_state(). Signed-off-by: Saravana Kannan --- .../admin-guide/kernel-parameters.txt | 14 +++++ drivers/base/base.h | 1 + drivers/base/core.c | 58 +++++++++++++++++++ drivers/base/dd.c | 6 ++ 4 files changed, 79 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentatio= n/admin-guide/kernel-parameters.txt index 6221a1d057dd..fc5dc4dc9a5c 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1582,6 +1582,20 @@ dependencies. This only applies for fw_devlink=3Don|rpm. Format: =20 + fw_devlink.sync_state =3D + [KNL] When all devices that could probe have finished + probing, this parameter controls what to do with + devices that haven't yet received their sync_state() + calls. + Format: { strict | timeout } + strict -- Default. Continue waiting on consumers to + probe successfully. + timeout -- Give up waiting on consumers and call + sync_state() on any devices that haven't yet + received their sync_state() calls after + deferred_probe_timeout has expired or by + late_initcall() if !CONFIG_MODULES. + gamecon.map[2|3]=3D [HW,JOY] Multisystem joystick and NES/SNES/PSX pad support via parallel port (up to 5 devices per port) diff --git a/drivers/base/base.h b/drivers/base/base.h index 726a12a244c0..6fcd71803d35 100644 --- a/drivers/base/base.h +++ b/drivers/base/base.h @@ -209,6 +209,7 @@ extern void device_links_no_driver(struct device *dev); extern bool device_links_busy(struct device *dev); extern void device_links_unbind_consumers(struct device *dev); extern void fw_devlink_drivers_done(void); +extern void fw_devlink_probing_done(void); =20 /* device pm support */ void device_pm_move_to_tail(struct device *dev); diff --git a/drivers/base/core.c b/drivers/base/core.c index 6878dfcbf0d6..4c7e1550bb02 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -1685,6 +1685,26 @@ static int __init fw_devlink_strict_setup(char *arg) } early_param("fw_devlink.strict", fw_devlink_strict_setup); =20 +#define FW_DEVLINK_SYNC_STATE_STRICT 0 +#define FW_DEVLINK_SYNC_STATE_TIMEOUT 1 + +static int fw_devlink_sync_state; +static int __init fw_devlink_sync_state_setup(char *arg) +{ + if (!arg) + return -EINVAL; + + if (strcmp(arg, "strict") =3D=3D 0) { + fw_devlink_sync_state =3D FW_DEVLINK_SYNC_STATE_STRICT; + return 0; + } else if (strcmp(arg, "timeout") =3D=3D 0) { + fw_devlink_sync_state =3D FW_DEVLINK_SYNC_STATE_TIMEOUT; + return 0; + } + return -EINVAL; +} +early_param("fw_devlink.sync_state", fw_devlink_sync_state_setup); + static inline u32 fw_devlink_get_flags(u8 fwlink_flags) { if (fwlink_flags & FWLINK_FLAG_CYCLE) @@ -1755,6 +1775,44 @@ void fw_devlink_drivers_done(void) device_links_write_unlock(); } =20 +static int fw_devlink_dev_sync_state(struct device *dev, void *data) +{ + struct device_link *link =3D to_devlink(dev); + struct device *sup =3D link->supplier; + + if (!(link->flags & DL_FLAG_MANAGED) || + link->status =3D=3D DL_STATE_ACTIVE || sup->state_synced || + !dev_has_sync_state(sup)) + return 0; + + if (fw_devlink_sync_state =3D=3D FW_DEVLINK_SYNC_STATE_STRICT) { + dev_warn(sup, "sync_state() pending due to %s\n", + dev_name(link->consumer)); + return 0; + } + + if (!list_empty(&sup->links.defer_sync)) + return 0; + + dev_warn(sup, "Timed out. Forcing sync_state()\n"); + sup->state_synced =3D true; + get_device(sup); + list_add_tail(&sup->links.defer_sync, data); + + return 0; +} + +void fw_devlink_probing_done(void) +{ + LIST_HEAD(sync_list); + + device_links_write_lock(); + class_for_each_device(&devlink_class, NULL, &sync_list, + fw_devlink_dev_sync_state); + device_links_write_unlock(); + device_links_flush_sync_list(&sync_list, NULL); +} + /** * wait_for_init_devices_probe - Try to probe any device needed for init * diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 8def2ba08a82..84f07e0050dd 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -315,6 +315,8 @@ static void deferred_probe_timeout_work_func(struct wor= k_struct *work) list_for_each_entry(p, &deferred_probe_pending_list, deferred_probe) dev_info(p->device, "deferred probe pending\n"); mutex_unlock(&deferred_probe_mutex); + + fw_devlink_probing_done(); } static DECLARE_DELAYED_WORK(deferred_probe_timeout_work, deferred_probe_ti= meout_work_func); =20 @@ -364,6 +366,10 @@ static int deferred_probe_initcall(void) schedule_delayed_work(&deferred_probe_timeout_work, driver_deferred_probe_timeout * HZ); } + + if (!IS_ENABLED(CONFIG_MODULES)) + fw_devlink_probing_done(); + return 0; } late_initcall(deferred_probe_initcall); --=20 2.40.0.rc0.216.gc4246ad0f0-goog From nobody Tue Sep 9 12:16:49 2025 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 55B1BC61DA3 for ; Sat, 4 Mar 2023 00:54:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229801AbjCDAy3 (ORCPT ); Fri, 3 Mar 2023 19:54:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53034 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229737AbjCDAyX (ORCPT ); Fri, 3 Mar 2023 19:54:23 -0500 Received: from mail-pl1-x649.google.com (mail-pl1-x649.google.com [IPv6:2607:f8b0:4864:20::649]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 41B1966D0F for ; Fri, 3 Mar 2023 16:54:04 -0800 (PST) Received: by mail-pl1-x649.google.com with SMTP id iy17-20020a170903131100b0019ce046d8f3so2222318plb.23 for ; Fri, 03 Mar 2023 16:54:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; t=1677891244; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=+axuFcxAf29Ailu8n0Kx3xozD+Ba9C9GcmWlTun9X2U=; b=gN4/x6QXgyBQ8FP+VQLIwxIChCEBeKy/+ISBsxXLMHzbxL0V7tcc9sXnkf5xkn9GVM ygeGPLYXrNvN+4cU73z4cLNm+Ia38RYioD+v8enjBq+WQI2938pQBJebI69AW490Q/N6 qwb5PZIwJDwFWTT0kt8aes3Xy6S+DO9jWbQeigk7ITKIT1rL1wDLM6qLhrNmojgzAKTs /qSJIhMLenIGFDojvHRYn37QoJeb+q41mUUFIE3FxWBEfTbwH5p88cZ7Q1FN6tnZXliU XkuqRjOUn0bVAp8HdqAC+Rcp5EFiP6Hbs7sVe3vLDSVyaCVpUBnjegaiD89O+Q7F54Xf Y9/w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1677891244; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=+axuFcxAf29Ailu8n0Kx3xozD+Ba9C9GcmWlTun9X2U=; b=xqTkdOvHYXQgv0Bv5vyE4Eu3gkNCiXZiT1bPt8Za9/ZiIklPi0mi4mvK9/iAeqkVBZ uYxMduvAgqr9kDJnrCww2lZ3Mjm/kAFyXzWtqKEd6fOTyyPSG3BChrIp2yNqAgOKx3Ni 1K9Q7iIpEjSWGmnTSkpmRXpP4mT8MA9apqB0ckkTpuv4TATlmK9LaB9gJ8nz3DVRswSr S/fiYXNPlW4dq4V4FKyNETOnixwIbLEIrYpYjK7pJgOdXgBlGHtVQuGQoDtWDUX8GAbw yQsxrqDFGYcA6dvu1T/JmvmxFD1RgBzRMtXJ6UjcRcJELf2FanYXhR9sVQV5oBfKOinF F7+Q== X-Gm-Message-State: AO0yUKXsJCeAgseU9myDjLFbPPSxsdbQOb09epqaxg2k8tpnDUb9Bl7N bgoPGuHD2QTuoQmWN9b2KZGVhJVKs9eTlY4= X-Google-Smtp-Source: AK7set+d/S2wOEPQE0NtY/v4crsIIe3/Iz162mWj/zhCIaiIDYzqoE9SdW631JpZPhCp+bQDMhF/dYIjtkUTiVw= X-Received: from saravanak.san.corp.google.com ([2620:15c:2d:3:ef0c:d8be:ebb3:b639]) (user=saravanak job=sendgmr) by 2002:a17:90a:7bc6:b0:237:3d0c:8d58 with SMTP id d6-20020a17090a7bc600b002373d0c8d58mr1315425pjl.5.1677891243771; Fri, 03 Mar 2023 16:54:03 -0800 (PST) Date: Fri, 3 Mar 2023 16:53:54 -0800 In-Reply-To: <20230304005355.746421-1-saravanak@google.com> Message-Id: <20230304005355.746421-3-saravanak@google.com> Mime-Version: 1.0 References: <20230304005355.746421-1-saravanak@google.com> X-Mailer: git-send-email 2.40.0.rc0.216.gc4246ad0f0-goog Subject: [PATCH v2 2/2] driver core: Make state_synced device attribute writeable From: Saravana Kannan To: Jonathan Corbet , Greg Kroah-Hartman , "Rafael J. Wysocki" Cc: Saravana Kannan , Abel Vesa , Bjorn Andersson , Dmitry Baryshkov , Doug Anderson , Matthias Kaehlcke , kernel-team@android.com, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" If the file is written to and sync_state() hasn't been called for the device yet, then call sync_state() for the device independent of the state of its consumers. This is useful for supplier devices that have one or more consumers that don't have a driver but the consumers are in a state that don't use the resources supplied by the supplier device. This gives finer grained control than using the fw_devlink.sync_state=3Dtimeout kernel commandline parameter. Signed-off-by: Saravana Kannan --- .../ABI/testing/sysfs-devices-state_synced | 5 ++++ drivers/base/base.h | 8 +++++++ drivers/base/core.c | 5 +--- drivers/base/dd.c | 23 ++++++++++++++++++- 4 files changed, 36 insertions(+), 5 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-devices-state_synced b/Documen= tation/ABI/testing/sysfs-devices-state_synced index 0c922d7d02fc..c64636ddac41 100644 --- a/Documentation/ABI/testing/sysfs-devices-state_synced +++ b/Documentation/ABI/testing/sysfs-devices-state_synced @@ -21,4 +21,9 @@ Description: at the time the kernel starts are not affected or limited in any way by sync_state() callbacks. =20 + Writing "1" to this file will force a call to the device's + sync_state() function if it hasn't been called already. The + sync_state() call happens independent of the state of the + consumer devices. + =20 diff --git a/drivers/base/base.h b/drivers/base/base.h index 6fcd71803d35..b055eba1ec30 100644 --- a/drivers/base/base.h +++ b/drivers/base/base.h @@ -164,6 +164,14 @@ static inline int driver_match_device(struct device_dr= iver *drv, return drv->bus->match ? drv->bus->match(dev, drv) : 1; } =20 +static inline void dev_sync_state(struct device *dev) +{ + if (dev->bus->sync_state) + dev->bus->sync_state(dev); + else if (dev->driver && dev->driver->sync_state) + dev->driver->sync_state(dev); +} + extern int driver_add_groups(struct device_driver *drv, const struct attribute_group **groups); extern void driver_remove_groups(struct device_driver *drv, diff --git a/drivers/base/core.c b/drivers/base/core.c index 4c7e1550bb02..c74e6a40f0de 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -1173,10 +1173,7 @@ static void device_links_flush_sync_list(struct list= _head *list, if (dev !=3D dont_lock_dev) device_lock(dev); =20 - if (dev->bus->sync_state) - dev->bus->sync_state(dev); - else if (dev->driver && dev->driver->sync_state) - dev->driver->sync_state(dev); + dev_sync_state(dev); =20 if (dev !=3D dont_lock_dev) device_unlock(dev); diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 84f07e0050dd..7b9ab2050b84 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -510,6 +510,27 @@ EXPORT_SYMBOL_GPL(device_bind_driver); static atomic_t probe_count =3D ATOMIC_INIT(0); static DECLARE_WAIT_QUEUE_HEAD(probe_waitqueue); =20 +static ssize_t state_synced_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + int ret =3D 0; + + if (strcmp("1", buf)) + return -EINVAL; + + device_lock(dev); + if (!dev->state_synced) { + dev->state_synced =3D true; + dev_sync_state(dev); + } else { + ret =3D -EINVAL; + } + device_unlock(dev); + + return ret ? ret : count; +} + static ssize_t state_synced_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -521,7 +542,7 @@ static ssize_t state_synced_show(struct device *dev, =20 return sysfs_emit(buf, "%u\n", val); } -static DEVICE_ATTR_RO(state_synced); +static DEVICE_ATTR_RW(state_synced); =20 static void device_unbind_cleanup(struct device *dev) { --=20 2.40.0.rc0.216.gc4246ad0f0-goog