kernel/linux.git/drivers/usb/core/usb.c, branch v6.19.12

usb: core: use dedicated spinlock for offload state

2026-04-11T12:29:50+00:00

commit bd3d245b0fef571f93504904df62b8865b1c0d34 upstream. Replace the coarse USB device lock with a dedicated offload_lock spinlock to reduce contention during offload operations. Use offload_pm_locked to synchronize with PM transitions and replace the legacy offload_at_suspend flag. Optimize usb_offload_get/put by switching from auto-resume/suspend to pm_runtime_get_if_active(). This ensures offload state is only modified when the device is already active, avoiding unnecessary power transitions. Cc: stable Fixes: ef82a4803aab ("xhci: sideband: add api to trace sideband usage") Signed-off-by: Guan-Yu Lin Tested-by: Hailong Liu Acked-by: Mathias Nyman Link: https://patch.msgid.link/20260401123238.3790062-2-guanyulin@google.com Signed-off-by: Greg Kroah-Hartman

usb: core: Add tracepoints for device allocation and state changes

2025-10-22T08:58:30+00:00

Introduce new tracepoints to the USB core to improve debuggability of USB device lifecycle events. The following tracepoints are added: - usb_alloc_dev: Triggered when a new USB device structure is allocated, providing insights into early device setup. - usb_set_device_state: Triggered when the USB device state changes, allowing observation of the device's state transitions. These tracepoints capture detailed information about the USB device, including its name, speed, state, bus current value, and authorized flag. This will aid developers in diagnosing issues related to device enumeration within the USB subsystem. Examples: usb_alloc_dev: usb 1-1 speed UNKNOWN state attached 0mA [authorized] usb_set_device_state: usb 1-1 speed UNKNOWN state powered 0mA [authorized] usb_set_device_state: usb 1-1 speed full-speed state default 500mA [authorized] usb_set_device_state: usb 1-1 speed full-speed state default 500mA [authorized] usb_set_device_state: usb 1-1 speed full-speed state addressed 500mA [authorized] usb_set_device_state: usb 1-1 speed full-speed state configured 500mA [authorized] usb_set_device_state: usb 1-1 speed full-speed state suspended 500mA [authorized] usb_set_device_state: usb 1-1 speed full-speed state not attached 500mA [authorized] Signed-off-by: Kuen-Han Tsai Reviewed-by: Alan Stern Link: https://patch.msgid.link/20251015-usbcore-tracing-v2-2-5a14b5b9d4e0@google.com Signed-off-by: Greg Kroah-Hartman

usb: offload: add apis for offload usage tracking

2025-09-12T12:08:02+00:00

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

usb: core: support eUSB2 double bandwidth large isoc URB frames

2025-09-06T13:25:05+00:00

eUSB2 double isochronous in bandwidth devices support up to 6 transactions per microframe, and thus doubles the total bytes possible to receive per microframe. Support larger URB isoc frame sizes for eUSB2 double isoc in endpoints. Also usb_endpoint_maxp() returns a natural number so there's no need to assume it could be < 0. Signed-off-by: Rai, Amardeep Reviewed-by: Sakari Ailus Signed-off-by: Mathias Nyman Co-developed-by: Sakari Ailus Signed-off-by: Sakari Ailus Acked-by: Alan Stern Acked-by: Mathias Nyman Signed-off-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20250820143824.551777-9-sakari.ailus@linux.intel.com

usb: core: Introduce usb_endpoint_is_hs_isoc_double()

2025-09-06T13:25:05+00:00

Introduce usb_endpoint_is_hs_isoc_double() tell whether an endpoint conforms to USB 2.0 Isochronous Double IN Bandwidth ECN. Signed-off-by: Sakari Ailus Acked-by: Mathias Nyman Signed-off-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20250820143824.551777-7-sakari.ailus@linux.intel.com

usb: core: Add a function to get USB version independent periodic payload

2025-09-06T13:25:05+00:00

Add usb_endpoint_max_periodic_payload() to obtain maximum payload bytes in a service interval for isochronous and interrupt endpoints in a USB version independent way. Signed-off-by: Rai, Amardeep Signed-off-by: Mathias Nyman Co-developed-by: Sakari Ailus Signed-off-by: Sakari Ailus Reviewed-by: Hans de Goede Acked-by: Mathias Nyman Signed-off-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20250820143824.551777-5-sakari.ailus@linux.intel.com

usb: core: add dma-noncoherent buffer alloc and free API

2025-07-09T10:15:56+00:00

This will add usb_alloc_noncoherent() and usb_free_noncoherent() functions to support alloc and free buffer in a dma-noncoherent way. To explicit manage the memory ownership for the kernel and device, this will also add usb_dma_noncoherent_sync_for_cpu/device() functions and call it at proper time. The management requires the user save sg_table returned by usb_alloc_noncoherent() to urb->sgt. Signed-off-by: Xu Yang Reviewed-by: Alan Stern Link: https://lore.kernel.org/r/20250704095751.73765-2-xu.yang_2@nxp.com Signed-off-by: Greg Kroah-Hartman

usb: Add checks for snprintf() calls in usb_alloc_dev()

2025-04-11T14:08:34+00:00

When creating a device path in the driver the snprintf() takes up to 16 characters long argument along with the additional up to 12 characters for the signed integer (as it can't see the actual limits) and tries to pack this into 16 bytes array. GCC complains about that when build with `make W=1`: drivers/usb/core/usb.c:705:25: note: ‘snprintf’ output between 3 and 28 bytes into a destination of size 16 Since everything works until now, let's just check for the potential buffer overflow and bail out. It is most likely a never happen situation, but at least it makes GCC happy. Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20250321164949.423957-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman

usb: add missing MODULE_DESCRIPTION() macros

2024-06-20T17:18:52+00:00

With ARCH=x86, make allmodconfig && make W=1 C=1 reports: WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/core/usbcore.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/mon/usbmon.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/class/usbtmc.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/storage/uas.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/chipidea/ci_hdrc_msm.o Add the missing invocations of the MODULE_DESCRIPTION() macro. Signed-off-by: Jeff Johnson Link: https://lore.kernel.org/r/20240618-md-drivers-usb-v2-1-e9b20a5eb7f9@quicinc.com Signed-off-by: Greg Kroah-Hartman

usb: core: constify the struct device_type usage

2024-02-19T08:35:46+00:00

Since commit aed65af1cc2f ("drivers: make device_type const"), the driver core can properly handle constant struct device_type. Move the usb_device_type, usb_if_device_type, usb_ep_device_type and usb_port_device_type variables to be constant structures as well, placing it into read-only memory which can not be modified at runtime. Signed-off-by: Ricardo B. Marliere Link: https://lore.kernel.org/r/20240218-device_cleanup-usb-v1-4-77423c4da262@marliere.net Signed-off-by: Greg Kroah-Hartman