From 7f70b89b2be66c03ddc76d3ad8aebeeec4a9c505 Mon Sep 17 00:00:00 2001 From: Guan-Yu Lin Date: Thu, 11 Sep 2025 14:20:14 +0000 Subject: usb: offload: add apis for offload usage tracking 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 Link: https://lore.kernel.org/r/20250911142051.90822-3-guanyulin@google.com Signed-off-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20250911142051.90822-3-guanyulin@google.com --- include/linux/usb.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'include/linux') diff --git a/include/linux/usb.h b/include/linux/usb.h index 70ef00c42d22..e85105939af8 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -636,6 +636,8 @@ struct usb3_lpm_parameters { * @do_remote_wakeup: remote wakeup should be enabled * @reset_resume: needs reset instead of resume * @port_is_suspended: the upstream port is suspended (L2 or U3) + * @offload_at_suspend: offload activities during suspend is enabled. + * @offload_usage: number of offload activities happening on this usb device. * @slot_id: Slot ID assigned by xHCI * @l1_params: best effor service latency for USB2 L1 LPM state, and L1 timeout. * @u1_params: exit latencies for USB3 U1 LPM state, and hub-initiated timeout. @@ -724,6 +726,8 @@ struct usb_device { unsigned do_remote_wakeup:1; unsigned reset_resume:1; unsigned port_is_suspended:1; + unsigned offload_at_suspend:1; + int offload_usage; enum usb_link_tunnel_mode tunnel_mode; struct device_link *usb4_link; @@ -841,6 +845,20 @@ static inline void usb_mark_last_busy(struct usb_device *udev) { } #endif +#if IS_ENABLED(CONFIG_USB_XHCI_SIDEBAND) +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. */ -- cgit v1.2.3