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

usb: core: new quirk to handle devices with zero configurations

2026-04-02T11:25:22+00:00

[ Upstream commit 9f6a983cfa22ac662c86e60816d3a357d4b551e9 ] Some USB devices incorrectly report bNumConfigurations as 0 in their device descriptor, which causes the USB core to reject them during enumeration. logs: usb 1-2: device descriptor read/64, error -71 usb 1-2: no configurations usb 1-2: can't read configurations, error -22 However, these devices actually work correctly when treated as having a single configuration. Add a new quirk USB_QUIRK_FORCE_ONE_CONFIG to handle such devices. When this quirk is set, assume the device has 1 configuration instead of failing with -EINVAL. This quirk is applied to the device with VID:PID 5131:2007 which exhibits this behavior. Signed-off-by: Jie Deng Link: https://patch.msgid.link/20260227084931.1527461-1-dengjie03@kylinos.cn Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

usb: core: add USB_QUIRK_NO_BOS for devices that hang on BOS descriptor

2026-01-07T16:07:00+00:00

Add USB_QUIRK_NO_BOS quirk flag to skip requesting the BOS descriptor for devices that cannot handle it. Add Elgato 4K X (0fd9:009b) to the quirk table. This device hangs when the BOS descriptor is requested at SuperSpeed Plus (10Gbps). Link: https://bugzilla.kernel.org/show_bug.cgi?id=220027 Cc: stable Signed-off-by: Johannes Brüderl Link: https://patch.msgid.link/20251207090220.14807-1-johannes.bruederl@gmail.com Signed-off-by: Greg Kroah-Hartman

usb: core: eUSB2 companion descriptor is for isoc IN endpoints only

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

The eUSB2 isochronous double bandwidth endpoint descriptor is allowed for the isochronous IN endpoints, according to the ECN. Do not parse these descriptors if they are found in interrupt or OUT endpoints. Signed-off-by: Sakari Ailus Acked-by: Mathias Nyman Signed-off-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20250820143824.551777-4-sakari.ailus@linux.intel.com

usb: core: Parse eUSB2 companion descriptors for high speed devices only

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

Check that a device is a high-speed one before proceeding to parse the eUSB2 isochronous endpoint companion descriptors. Signed-off-by: Sakari Ailus Acked-by: Mathias Nyman Signed-off-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20250820143824.551777-3-sakari.ailus@linux.intel.com

usb: core: Use le16_to_cpu() to read __le16 value in usb_parse_endpoint()

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

wMaxPacketSize field in struct usb_endpoint_descriptor is an __le16, use le16_to_cpu() to read it. Signed-off-by: Sakari Ailus Acked-by: Mathias Nyman Signed-off-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20250820143824.551777-2-sakari.ailus@linux.intel.com

usb: core: config: Prevent OOB read in SS endpoint companion parsing

2025-07-01T14:16:32+00:00

usb_parse_ss_endpoint_companion() checks descriptor type before length, enabling a potentially odd read outside of the buffer size. Fix this up by checking the size first before looking at any of the fields in the descriptor. Signed-off-by: Xinyu Liu Cc: stable Signed-off-by: Greg Kroah-Hartman

usb: core: config: Use USB API functions rather than constants

2025-05-21T11:13:18+00:00

Use the function usb_endpoint_num() rather than constants. The Coccinelle semantic patch is as follows: @@ struct usb_endpoint_descriptor *epd; @@ - (epd->bEndpointAddress & \(USB_ENDPOINT_NUMBER_MASK\|0x0f\)) + usb_endpoint_num(epd) Signed-off-by: Chen Ni Link: https://lore.kernel.org/r/20250519061317.724602-1-nichen@iscas.ac.cn Signed-off-by: Greg Kroah-Hartman

USB: core: Add eUSB2 descriptor and parsing in USB core

2025-02-21T09:45:32+00:00

Add support for the 'eUSB2 Isochronous Endpoint Companion Descriptor' introduced in the recent USB 2.0 specification 'USB 2.0 Double Isochronous IN Bandwidth' ECN. It allows embedded USB2 (eUSB2) devices to report and use higher bandwidths for isochronous IN transfers in order to support higher camera resolutions on the lid of laptops and tablets with minimal change to the USB2 protocol. The motivation for expanding USB 2.0 is further clarified in an additional Embedded USB2 version 2.0 (eUSB2v2) supplement to the USB 2.0 specification. It points out this is optimized for performance, power and cost by using the USB 2.0 low-voltage, power efficient PHY and half-duplex link for the asymmetric camera bandwidth needs, avoiding the costly and complex full-duplex USB 3.x symmetric link and gigabit receivers. eUSB2 devices that support the higher isochronous IN bandwidth and the new descriptor can be identified by their device descriptor bcdUSB value of 0x0220 Co-developed-by: Amardeep Rai Signed-off-by: Amardeep Rai Signed-off-by: Kannappan R Co-developed-by: Mathias Nyman Signed-off-by: Mathias Nyman Acked-by: Alan Stern Link: https://lore.kernel.org/r/20250220141339.1939448-1-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman

USB: Replace own str_plural with common one

2025-01-15T17:28:12+00:00

Use existing str_plural() helper from string_choices.h to reduce amount of duplicated code. Signed-off-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/20250114-str-enable-disable-usb-v1-1-c8405df47c19@linaro.org Signed-off-by: Greg Kroah-Hartman

drivers/usb/core: refactor max with max_t

2024-11-13T14:09:50+00:00

Ensure type safety by using max_t() instead of max(). Signed-off-by: Sabyrzhan Tasbolatov Link: https://lore.kernel.org/r/20241112155817.3512577-3-snovitoll@gmail.com Signed-off-by: Greg Kroah-Hartman