From nobody Fri Sep 12 02:28:50 2025 Received: from mail-pl1-f201.google.com (mail-pl1-f201.google.com [209.85.214.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9E9111F8753 for ; Wed, 16 Apr 2025 14:49:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744814992; cv=none; b=aRHbE31aFDcIwPYKP2hgDAuGVsq0u/HUskZovuVd9ajHgrGH5H2lB3zQ2KCoDUF6xrDxeccEFnU5lYKOab3eYDj7r5j8eczX0JXndBKFUyFeKLtuU2C0t77+Mvu3YJgqaa0PUDJsp57cqU//mnbIO9EW0+GNBHV9yVkxuvyxzK8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744814992; c=relaxed/simple; bh=BF+JAj2OOaQYBf1pV/aU5GDWs5SSoNcddA0RfvFTnYo=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=dGoI1P0SBmAS3EhQv9fZMkH5NaZUFXpJG92b8X7dOCqtWzcMpgr7bxS/b3JscAqiwT+J2NBvz8A+Cto3ZDCd64ZrHprHLlDZZcydVIRb6dwl+BwtT9nvYzAVWgccxbqGbH9y8LX7B4HiBvIB80Rv7MI9HUApqXcf51nSgwuiwws= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--guanyulin.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=uAVtuNV9; arc=none smtp.client-ip=209.85.214.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--guanyulin.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="uAVtuNV9" Received: by mail-pl1-f201.google.com with SMTP id d9443c01a7336-225ab228a37so60985835ad.2 for ; Wed, 16 Apr 2025 07:49:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1744814990; x=1745419790; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=jpoAHz8CQifRQNDsLq9w1aYT2twGEmc33VKgu5HbVd4=; b=uAVtuNV90u42vXQatI0OcZSAgqes+VqY3kTKs0rsIPOGNfgVEkUC2JJTCY63wNpvxR 6QbalZUGoQwLDhDzWflN45t8WWwie2BRi8O4ueyjUsSya9e9Wysz2xGeHlPs2sMNYoK+ L28PD54C17IbfF5N2KhRejE00iJ0ZTUaxI6OrXhsdbI/BlmhKp3S0r/t7Tj256UXKL6/ LJg93UMCpLjM89HYSzSn40Xm+jEW+b2DdOhDfuBnCdEj4B98n53vDlBkvG/iXeKOS6xm V6FRfcKhNLkx2zjOgMBth1RoYYQ/tr3c+p8Ye+EpNy8zsI31ZD2D5ZeBfRDsB1sgI00t JKpg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1744814990; x=1745419790; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=jpoAHz8CQifRQNDsLq9w1aYT2twGEmc33VKgu5HbVd4=; b=lVl+arrtvB3vJcMN0oCeM2Ol4g12rtJzZAO0wAN7Auh2tluKzrChE6qgKoJ24d4Kz4 j3xiBY3u0r7g9zBWHBT21owshrvAcXY9ZyoHpZfA9+4HowUMVseXHfx4lKVNcwJSLyJj fTAEztDTaF6nvofsees+ofRiRerspV6QBljS4Wdbj463m+v4ZdKNUZd/ChU8ip1OTHtz ERiPPgnfp61ueBUczIX27K5st0AluTUcgns5zphBt65LjfJ5n3KB8eS5WVNp+2pb19WB PSVGgibcvjoEtMC0gP5Nz8zVh1UHAG6COctKj6ao3UC2eXFVGZyXZ4h59bZpjCAaWDRL pO0g== X-Forwarded-Encrypted: i=1; AJvYcCUjqLDj10d/GYUVF0rA4fUchk78DBI0Db4DuOKFmIUJndRQ6mrYzjCQwnK/EF6udV+w20TPiyhdagk97GU=@vger.kernel.org X-Gm-Message-State: AOJu0YwXIQ4teVwNNM3ICnvCVD/vMH0quZBEiN8INkkLMmUiH95Z6Jfz LKOiXMEvJMIV9cVSy5r7CbiNi+JtWNiQMQf+4kjHoFqSqHogleDqz6NphknGPAMe6DOtfEXBt5Y byK/nohP5R/U35Q== X-Google-Smtp-Source: AGHT+IHWFuvR6Ztz9iFG7HJ6rrbohaJudddMdBJrQPKvVdlWZLt0+eDvsLNfkM/8AlAMBx6OIgZF13ireeqRb9o= X-Received: from plgw17.prod.google.com ([2002:a17:902:e891:b0:227:967c:4f38]) (user=guanyulin job=prod-delivery.src-stubby-dispatcher) by 2002:a17:902:ef03:b0:223:3bf6:7e6a with SMTP id d9443c01a7336-22c358d9a54mr43379605ad.12.1744814989997; Wed, 16 Apr 2025 07:49:49 -0700 (PDT) Date: Wed, 16 Apr 2025 14:43:02 +0000 In-Reply-To: <20250416144917.16822-1-guanyulin@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250416144917.16822-1-guanyulin@google.com> X-Mailer: git-send-email 2.49.0.604.gff1f9ca942-goog Message-ID: <20250416144917.16822-3-guanyulin@google.com> Subject: [PATCH v12 2/4] usb: add apis for offload usage tracking From: Guan-Yu Lin To: gregkh@linuxfoundation.org, mathias.nyman@intel.com, stern@rowland.harvard.edu, sumit.garg@kernel.org, gargaditya08@live.com, kekrby@gmail.com, jeff.johnson@oss.qualcomm.com, quic_zijuhu@quicinc.com, andriy.shevchenko@linux.intel.com, ben@decadent.org.uk, broonie@kernel.org, quic_wcheng@quicinc.com Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Guan-Yu Lin Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Introduce offload_usage and corresponding apis to track offload usage on each USB device. Offload denotes that there is another co-processor accessing the USB device via the same USB host controller. To optimize power usage, it's essential to monitor whether the USB device is actively used by other co-processor. This information is vital when determining if a USB device can be safely suspended during system power state transitions. Signed-off-by: Guan-Yu Lin --- drivers/usb/core/driver.c | 109 ++++++++++++++++++++++++++++++++++++++ drivers/usb/core/usb.c | 1 + drivers/usb/host/Kconfig | 11 ++++ include/linux/usb.h | 17 ++++++ 4 files changed, 138 insertions(+) diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index 460d4dde5994..76372690add0 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -2036,6 +2036,115 @@ int usb_disable_usb2_hardware_lpm(struct usb_device= *udev) =20 #endif /* CONFIG_PM */ =20 +#if IS_ENABLED(CONFIG_USB_XHCI_SIDEBAND_SUSPEND) + +/** + * usb_offload_get - increment the offload_usage of a USB device + * @udev: the USB device to increment its offload_usage + * + * Incrementing the offload_usage of a usb_device indicates that offload is + * enabled on this usb_device; that is, another entity is actively handlin= g USB + * transfers. This information allows the USB driver to adjust its power + * management policy based on offload activity. + * + * The caller must hold @udev's device lock. + * + * Return: 0 on success. A negative error code otherwise. + */ +int usb_offload_get(struct usb_device *udev) +{ + int ret; + + if (udev->state =3D=3D USB_STATE_NOTATTACHED || + udev->state =3D=3D USB_STATE_SUSPENDED) + return -EAGAIN; + + /* + * offload_usage could only be modified when the device is active, since + * it will alter the suspend flow of the device. + */ + ret =3D usb_autoresume_device(udev); + + if (ret < 0) + return ret; + + udev->offload_usage++; + usb_autosuspend_device(udev); + + return 0; +} +EXPORT_SYMBOL_GPL(usb_offload_get); + +/** + * usb_offload_put - drop the offload_usage of a USB device + * @udev: the USB device to drop its offload_usage + * + * The inverse operation of usb_offload_get, which drops the offload_usage= of + * a USB device. This information allows the USB driver to adjust its power + * management policy based on offload activity. + * + * The caller must hold @udev's device lock. + * + * Return: 0 on success. A negative error code otherwise. + */ +int usb_offload_put(struct usb_device *udev) +{ + int ret; + + if (udev->state =3D=3D USB_STATE_NOTATTACHED || + udev->state =3D=3D USB_STATE_SUSPENDED) + return -EAGAIN; + + /* + * offload_usage could only be modified when the device is active, since + * it will alter the suspend flow of the device. + */ + ret =3D usb_autoresume_device(udev); + + if (ret < 0) + return ret; + + /* Drop the count when it wasn't 0, ignore the operation otherwise. */ + if (udev->offload_usage) + udev->offload_usage--; + usb_autosuspend_device(udev); + + return 0; +} +EXPORT_SYMBOL_GPL(usb_offload_put); + +/** + * usb_offload_check - check offload activities on a USB device + * @udev: the USB device to check its offload activity. + * + * Check if there are any offload activity on the USB device right now. Th= is + * information could be used for power management or other forms of resour= ce + * management. + * + * The caller must hold @udev's device lock. + * + * Returns true on any offload activity, false otherwise. + */ +bool usb_offload_check(struct usb_device *udev) +{ + struct usb_device *child; + bool active; + int port1; + + usb_hub_for_each_child(udev, port1, child) { + device_lock(&child->dev); + active =3D usb_offload_check(child); + device_unlock(&child->dev); + if (active) + return true; + } + + return !!udev->offload_usage; +} +EXPORT_SYMBOL_GPL(usb_offload_check); + +#endif /* IS_ENABLED(CONFIG_USB_XHCI_SIDEBAND_SUSPEND) */ + const struct bus_type usb_bus_type =3D { .name =3D "usb", .match =3D usb_device_match, diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c index 118fa4c93a79..43efd9d939c0 100644 --- a/drivers/usb/core/usb.c +++ b/drivers/usb/core/usb.c @@ -670,6 +670,7 @@ struct usb_device *usb_alloc_dev(struct usb_device *par= ent, set_dev_node(&dev->dev, dev_to_node(bus->sysdev)); dev->state =3D USB_STATE_ATTACHED; dev->lpm_disable_count =3D 1; + dev->offload_usage =3D 0; atomic_set(&dev->urbnum, 0); =20 INIT_LIST_HEAD(&dev->ep0.urb_list); diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig index 033a9a4b51fe..b564f46f1c87 100644 --- a/drivers/usb/host/Kconfig +++ b/drivers/usb/host/Kconfig @@ -113,6 +113,17 @@ config USB_XHCI_SIDEBAND xHCI USB endpoints directly, allowing CPU to sleep while playing audio. =20 +config USB_XHCI_SIDEBAND_SUSPEND + bool "xHCI support for sideband during system suspend" + depends on USB_XHCI_SIDEBAND + depends on USB_XHCI_PLATFORM + depends on SUSPEND + help + Say 'Y' to enable the support for the xHCI sideband capability + after system suspended. In addition to USB_XHCI_SIDEBAND, this + config allows endpoints and interrupters associated with the + sideband function when system is suspended. + config USB_XHCI_TEGRA tristate "xHCI support for NVIDIA Tegra SoCs" depends on PHY_TEGRA_XUSB diff --git a/include/linux/usb.h b/include/linux/usb.h index 1b2545b4363b..ec8d839e1e2b 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -647,6 +647,7 @@ struct usb3_lpm_parameters { * parent->hub_delay + wHubDelay + tTPTransmissionDelay (40ns) * Will be used as wValue for SetIsochDelay requests. * @use_generic_driver: ask driver core to reprobe using the generic drive= r. + * @offload_usage: number of offload activities happening on this usb devi= ce. * * Notes: * Usbcore drivers should not set usbdev->state directly. Instead use @@ -733,6 +734,8 @@ struct usb_device { =20 u16 hub_delay; unsigned use_generic_driver:1; + + int offload_usage; }; =20 #define to_usb_device(__dev) container_of_const(__dev, struct usb_device, = dev) @@ -839,6 +842,20 @@ static inline void usb_mark_last_busy(struct usb_devic= e *udev) { } #endif =20 +#if IS_ENABLED(CONFIG_USB_XHCI_SIDEBAND_SUSPEND) +int usb_offload_get(struct usb_device *udev); +int usb_offload_put(struct usb_device *udev); +bool usb_offload_check(struct usb_device *udev); +#else + +static inline int usb_offload_get(struct usb_device *udev) +{ return 0; } +static inline int usb_offload_put(struct usb_device *udev) +{ return 0; } +static inline bool usb_offload_check(struct usb_device *udev) +{ return false; } +#endif + extern int usb_disable_lpm(struct usb_device *udev); extern void usb_enable_lpm(struct usb_device *udev); /* Same as above, but these functions lock/unlock the bandwidth_mutex. */ --=20 2.49.0.604.gff1f9ca942-goog