From patchwork Thu Jan 16 13:50:15 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guan-Yu Lin X-Patchwork-Id: 13941703 Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (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 D376922A804 for ; Thu, 16 Jan 2025 13:54:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737035682; cv=none; b=LpEdKSthSO48+NmQwVVE64FI3ACoop16ek1yLo4hZ0BZO0P+fOXtA36et+1lfKYIzDZ1t153rhypYp6GnvBwgCuKml93U1yepZYIIesQeZ6FvieEdhlBNijyQVBbuzcbu/iENQLDgUvgUwHsqc3lDPOduoksyvtEEPs+XNMja6s= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737035682; c=relaxed/simple; bh=iHbXpApZXMdoYmO22LcNZiKWepotlBPXNi3hKmTmmTQ=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=CpRHBbbkiLUSlHQkzLeqClaOBIQzgkvKqpp8N6nutJRoEepqsETruMujZ4qbwTxMxrIB3F/ekqrJg6rF66U/j//2vjq5e/HJY3xyxj0ZNN+vcS4AHOye+5vGXOqJM7L9z5ovAOTox8I0iJLTQOM/UmAIbWwGcE0mcMn6DU0lfyU= 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=zXM7CRV2; arc=none smtp.client-ip=209.85.216.74 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="zXM7CRV2" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-2ef114d8346so2043205a91.0 for ; Thu, 16 Jan 2025 05:54:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1737035680; x=1737640480; 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=frSvqT6dyBKNEvGXV8Wp1l7540diAFryFwfnWgvRajk=; b=zXM7CRV23PYb7E3Eyo0jd9wkVBdN+KBRFM3sVdGmk8mnL23rDTnWo+q8mXve+I/7Yb 2jup6msmE96/yNjPx+JFQviaRp8H1pWi5dCA/FQGe4c3b7R1ujM76sbbaBCygz9ROFDD zHeAYHVgFJOSrNOjyOgn0XG1kjyms4isd8LK8GHSOD8JRJrlUTqmVx/azG4eE+7Sq7DI cJOi11zi2Uk5S+PgFzbw9oU7y0BbZJEy1Nm2l5yVQaejPdt++NJvAYTi3AW7hjcfkcq8 wb/TZVD0XmoK56tTeremOjbjU6ynUOnuAM/H/0ED+HgNJYjZ7MWu+UfV8IUsEZDqftE1 Owag== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1737035680; x=1737640480; 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=frSvqT6dyBKNEvGXV8Wp1l7540diAFryFwfnWgvRajk=; b=K3jlEAxY2yjjFtE8sxXspHyV6C07qfoAyE1khvXVTi5a23aw7kYpAcyD4Th1HgH6Bx ACCoCYwK71RTY/5Z8Y0XBXcWiSEjO3rhcNDZAVNjqm/qmlY2XvbzjwU+u+B7gVrsOvvj YIhsyr2QPp+Y51Ot2UCBGZjiEsajyl91Fp25ihSzUvr3JLNUohbjNdvAe5NBPI5cnw+7 0o5Kfcj+PEhZPvZwWK7dQJKM5LDzWZ4VkkawwwwgvNH5EguxHZ56GPwTze637zxlE5vg AHXKkOSJYyt1eUMXUoB2xSCQ4ViBJFjrpOOqtG72iNB/1A06mGhGBH8CCvwb7nWvI6ek xSYQ== X-Forwarded-Encrypted: i=1; AJvYcCXOy4r6eM/3eH0Kz00BYBSfDE65Ylyc+dcj2D7z47okAQT4sGZ2rxJNkai0Oxecn6iJQqluRKoyJCCVFQ==@vger.kernel.org X-Gm-Message-State: AOJu0YyaLiUwdbsC7NazwEAG0oD7N8Ki17Y1tggfz2p7J/lwDOBIkylp ErgdbT1DV0R4xgkevEqtY6vrMPvKsAUiBOtj3ZKxJia5M2rb7y8xw+q5Z+zfzdw4KN2R+cVrZQ7 ap+8WDlP9JQRL3w== X-Google-Smtp-Source: AGHT+IEFXpmhl6Uk6fSDur8w3nPtXbWer5SIEq/xjrwyyv25VZQnR2zXm1NoGGgYMQnYj1N80prvPspuV5zRs7g= X-Received: from pjbcz3.prod.google.com ([2002:a17:90a:d443:b0:2ea:aa56:49c]) (user=guanyulin job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:56cb:b0:2ee:c04a:4281 with SMTP id 98e67ed59e1d1-2f548f102demr43736693a91.6.1737035680439; Thu, 16 Jan 2025 05:54:40 -0800 (PST) Date: Thu, 16 Jan 2025 13:50:15 +0000 In-Reply-To: <20250116135358.2335615-1-guanyulin@google.com> Precedence: bulk X-Mailing-List: linux-sound@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250116135358.2335615-1-guanyulin@google.com> X-Mailer: git-send-email 2.48.0.rc2.279.g1de40edade-goog Message-ID: <20250116135358.2335615-4-guanyulin@google.com> Subject: [PATCH v8 3/5] usb: add apis for offload usage tracking From: Guan-Yu Lin To: gregkh@linuxfoundation.org, Thinh.Nguyen@synopsys.com, mathias.nyman@intel.com, stern@rowland.harvard.edu, perex@perex.cz, tiwai@suse.com, sumit.garg@linaro.org, kekrby@gmail.com, oneukum@suse.com, ricardo@marliere.net, lijiayi@kylinos.cn, quic_jjohnson@quicinc.com Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, linux-sound@vger.kernel.org, Guan-Yu Lin 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 | 108 ++++++++++++++++++++++++++++++++++++++ drivers/usb/core/usb.c | 4 ++ include/linux/usb.h | 19 +++++++ 3 files changed, 131 insertions(+) diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index f203fdbfb6f6..1bbf9592724f 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -2037,6 +2037,114 @@ int usb_disable_usb2_hardware_lpm(struct usb_device *udev) #endif /* CONFIG_PM */ +#ifdef CONFIG_USB_XHCI_SIDEBAND + +/** + * 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 handling 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 == USB_STATE_NOTATTACHED || + udev->state == 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 = pm_runtime_resume_and_get(&udev->dev); + + if (ret < 0) + return ret; + + refcount_inc(&udev->offload_usage); + pm_runtime_put_sync(&udev->dev); + + 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 == USB_STATE_NOTATTACHED || + udev->state == 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 = pm_runtime_resume_and_get(&udev->dev); + + if (ret < 0) + return ret; + + /* Drop the count when it wasn't 0, ignore the operation otherwise. */ + ret = refcount_add_not_zero(-1, &udev->offload_usage); + pm_runtime_put_sync(&udev->dev); + + 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. This + * information could be used for power management or other forms of resource + * 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 = usb_offload_check(child); + device_unlock(&child->dev); + if (active) + return true; + } + + return !!refcount_read(&udev->offload_usage); +} +EXPORT_SYMBOL_GPL(usb_offload_check); + +#endif /* CONFIG_USB_XHCI_SIDEBAND */ + const struct bus_type usb_bus_type = { .name = "usb", .match = usb_device_match, diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c index 0b4685aad2d5..888ab599fd06 100644 --- a/drivers/usb/core/usb.c +++ b/drivers/usb/core/usb.c @@ -672,6 +672,10 @@ struct usb_device *usb_alloc_dev(struct usb_device *parent, dev->lpm_disable_count = 1; atomic_set(&dev->urbnum, 0); +#ifdef CONFIG_USB_XHCI_SIDEBAND + refcount_set(&dev->offload_usage, 0); +#endif + INIT_LIST_HEAD(&dev->ep0.urb_list); dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE; dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT; diff --git a/include/linux/usb.h b/include/linux/usb.h index cfa8005e24f9..9b3f630e763e 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -645,6 +645,7 @@ 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 driver. + * @offload_usage: number of offload activities happening on this usb device. * * Notes: * Usbcore drivers should not set usbdev->state directly. Instead use @@ -731,6 +732,10 @@ struct usb_device { u16 hub_delay; unsigned use_generic_driver:1; + +#ifdef CONFIG_USB_XHCI_SIDEBAND + refcount_t offload_usage; +#endif }; #define to_usb_device(__dev) container_of_const(__dev, struct usb_device, dev) @@ -837,6 +842,20 @@ static inline void usb_mark_last_busy(struct usb_device *udev) { } #endif +#ifdef CONFIG_USB_XHCI_SIDEBAND +extern int usb_offload_get(struct usb_device *udev); +extern int usb_offload_put(struct usb_device *udev); +extern 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. */