kernel/linux.git/drivers/usb/class/cdc-acm.c, branch linux-7.0.y

USB: cdc-acm: Add quirks for Yoga Book 9 14IAH10 INGENIC touchscreen

2026-04-22T11:32:17+00:00

commit f58752ebcb35e156c85cd1a82d6579c7af3b9023 upstream. The Lenovo Yoga Book 9 14IAH10 (83KJ) has a composite USB device (17EF:6161) that controls both touchscreens via a CDC ACM interface. Interface 0 is a standard CDC ACM control interface, but interface 1 (the data interface) incorrectly declares vendor-specific class (0xFF) instead of USB_CLASS_CDC_DATA. cdc-acm rejects the device at probe with -EINVAL, leaving interface 0 unbound and EP 0x82 never polled. With no consumer polling EP 0x82, the firmware's watchdog fires every ~20 seconds and resets the USB bus, producing a continuous disconnect/ reconnect loop that prevents the touchscreens from ever initialising. Add two new quirk flags: VENDOR_CLASS_DATA_IFACE: Bypasses the bInterfaceClass check in acm_probe() that would otherwise reject the vendor-class data interface with -EINVAL. ALWAYS_POLL_CTRL: Submits the notification URB at probe() rather than waiting for a TTY open. This keeps EP 0x82 polled at all times, permanently suppressing the firmware watchdog. The URB is resubmitted after port_shutdown() and on system resume. SET_CONTROL_LINE_STATE (DTR|RTS) is sent at probe and after port_shutdown() to complete firmware handshake. Note: the firmware performs exactly 4 USB connect/disconnect cycles (~19 s each) on every cold boot before stabilising. This is a fixed firmware property; touch is available ~75-80 s after power-on. Signed-off-by: Dave Carey Cc: stable Tested-by: Dave Carey Acked-by: Oliver Neukum Link: https://patch.msgid.link/20260402182950.389016-1-carvsdriver@gmail.com Signed-off-by: Greg Kroah-Hartman

cdc-acm: new quirk for EPSON HMD

2026-03-18T15:17:22+00:00

This device has a union descriptor that is just garbage and needs a custom descriptor. In principle this could be done with a (conditionally activated) heuristic. That would match more devices without a need for defining a new quirk. However, this always carries the risk that the heuristics does the wrong thing and leads to more breakage. Defining the quirk and telling it exactly what to do is the safe and conservative approach. Signed-off-by: Oliver Neukum Cc: stable Link: https://patch.msgid.link/20260317084139.1461008-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman

usb: cdc-acm: Restore CAP_BRK functionnality to CH343

2026-03-11T15:17:55+00:00

The CH343 USB/serial adapter is as buggy as it is popular (very). One of its quirks is that despite being capable of signalling a BREAK condition, it doesn't advertise it. This used to work nonetheless until 66aad7d8d3ec5 ("usb: cdc-acm: return correct error code on unsupported break") applied some reasonable restrictions, preventing breaks from being emitted on devices that do not advertise CAP_BRK. Add a quirk for this particular device, so that breaks can still be produced on some of my machines attached to my console server. Fixes: 66aad7d8d3ec5 ("usb: cdc-acm: return correct error code on unsupported break") Signed-off-by: Marc Zyngier Cc: stable Cc: Oliver Neukum Cc: Greg Kroah-Hartman Acked-by: Oliver Neukum Link: https://patch.msgid.link/20260301124440.1192752-1-maz@kernel.org Signed-off-by: Greg Kroah-Hartman

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

uapi: cdc.h: cleanly provide for more interfaces and countries

2025-11-21T14:12:12+00:00

The spec requires at least one interface respectively country. It allows multiple ones. This needs to be clearly said in the UAPI. This is subject to sanity checking in cdc_parse_cdc_header(), thus we can trust the length. Signed-off-by: Oliver Neukum Link: https://patch.msgid.link/20251111134641.4118827-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman

Merge tag 'usb-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb

2025-07-29T17:17:10+00:00

Pull USB / Thunderbolt updates from Greg KH: "Here is the big set of USB and Thunderbolt driver changes for 6.17-rc1. Lots of little things in here, mostly all small cleanups and updates, no major new features this development cycle. Stuff included in here is: - xhci minor tweaks for error handling - typec minor updates and a driver update - gadget driver api cleanups - unused function removals - unbind memory leak fixes - a few new device ids added - a few new devices supported for some drivers - other minor cleanups and changes All of these have been in linux-next with no reported issues, with the leak fixes being in the shortest amount of time, but they are 'obviously correct' :)" * tag 'usb-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (100 commits) usb: musb: omap2430: clean up probe error handling usb: musb: omap2430: fix device leak at unbind usb: gadget: udc: renesas_usb3: fix device leak at unbind usb: dwc3: meson-g12a: fix device leaks at unbind usb: dwc3: imx8mp: fix device leak at unbind usb: musb: omap2430: enable compile testing usb: gadget: udc: renesas_usb3: drop unused module alias usb: xhci: print xhci->xhc_state when queue_command failed usb: atm: cxacru: Merge cxacru_upload_firmware() into cxacru_heavy_init() USB: serial: option: add Foxconn T99W709 usb: core: add urb->sgt parameter description thunderbolt: Fix copy+paste error in match_service_id() usb: typec: ucsi: Update power_supply on power role change usb: typec: ucsi: psy: Set current max to 100mA for BC 1.2 and Default usb: typec: fusb302: cache PD RX state usb: typec: ucsi: yoga-c630: add DRM dependency usb: gadget : fix use-after-free in composite_dev_cleanup() usb: chipidea: imx: Add a missing blank line usb: gadget: f_uac1: replace scnprintf() with sysfs_emit() usb: usblp: clean up assignment inside if conditions ...

cdc-acm: fix race between initial clearing halt and open

2025-07-21T14:29:44+00:00

On the devices that need their endpoints to get an initial clear_halt, this needs to be done before the devices can be opened. That means it needs to be before the devices are registered. Fixes: 15bf722e6f6c0 ("cdc-acm: Add support of ATOL FPrint fiscal printers") Cc: stable Signed-off-by: Oliver Neukum Link: https://lore.kernel.org/r/20250717141259.2345605-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman

tty: introduce and use tty_port_tty_vhangup() helper

2025-06-17T11:42:33+00:00

This code (tty_get -> vhangup -> tty_put) is repeated on few places. Introduce a helper similar to tty_port_tty_hangup() (asynchronous) to handle even vhangup (synchronous). And use it on those places. In fact, reuse the tty_port_tty_hangup()'s code and call tty_vhangup() depending on a new bool parameter. Signed-off-by: "Jiri Slaby (SUSE)" Cc: Karsten Keil Cc: David Lin Cc: Johan Hovold Cc: Alex Elder Cc: Oliver Neukum Cc: Marcel Holtmann Cc: Johan Hedberg Cc: Luiz Augusto von Dentz Reviewed-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20250611100319.186924-2-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

USB: cdc-acm: Fill in Renesas R-Car D3 USB Download mode quirk

2025-02-14T08:22:36+00:00

Add Renesas R-Car D3 USB Download mode quirk and update comments on all the other Renesas R-Car USB Download mode quirks to discern them from each other. This follows R-Car Series, 3rd Generation reference manual Rev.2.00 chapter 19.2.8 USB download mode . Fixes: 6d853c9e4104 ("usb: cdc-acm: Add DISABLE_ECHO for Renesas USB Download mode") Cc: stable Signed-off-by: Marek Vasut Reviewed-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20250209145708.106914-1-marek.vasut+renesas@mailbox.org Signed-off-by: Greg Kroah-Hartman