This series starts returning errors from break handling and also uses that mechanism to report to user space when break signalling is not supported (e.g. when device or driver support is missing). Note that the tty layer currently returns early but without reporting errors when a tty driver does not support break signalling. The intent expressed in commit 9e98966c7bb9 ("tty: rework break handling") from 2008 appears to be to allow missing support to be reported to user space however. Johan Changes in v2 - fix return of potentially uninitialised status variable in io_edgeport as reported by kernel test robot <lkp@xxxxxxxxx> and Dan Carpenter: https://lore.kernel.org/all/202306031014.qzAY3uQ6-lkp@xxxxxxxxx/ Johan Hovold (3): USB: serial: return errors from break handling USB: serial: cp210x: disable break signalling on CP2105 SCI USB: serial: report unsupported break signalling drivers/usb/serial/ark3116.c | 7 +++-- drivers/usb/serial/belkin_sa.c | 12 ++++++--- drivers/usb/serial/ch341.c | 37 +++++++++++++++++---------- drivers/usb/serial/cp210x.c | 14 +++++++--- drivers/usb/serial/digi_acceleport.c | 7 ++--- drivers/usb/serial/f81232.c | 4 ++- drivers/usb/serial/f81534.c | 4 ++- drivers/usb/serial/ftdi_sio.c | 10 +++++--- drivers/usb/serial/io_edgeport.c | 6 +++-- drivers/usb/serial/io_ti.c | 9 +++++-- drivers/usb/serial/keyspan.c | 5 +++- drivers/usb/serial/keyspan_pda.c | 8 ++++-- drivers/usb/serial/mct_u232.c | 6 ++--- drivers/usb/serial/mos7720.c | 9 ++++--- drivers/usb/serial/mos7840.c | 7 ++--- drivers/usb/serial/mxuport.c | 6 ++--- drivers/usb/serial/pl2303.c | 14 ++++++---- drivers/usb/serial/quatech2.c | 8 ++++-- drivers/usb/serial/ti_usb_3410_5052.c | 10 +++++--- drivers/usb/serial/upd78f0730.c | 7 +++-- drivers/usb/serial/usb-serial.c | 4 +-- drivers/usb/serial/usb_debug.c | 13 +++++++--- drivers/usb/serial/whiteheat.c | 7 ++--- drivers/usb/serial/xr_serial.c | 4 +-- include/linux/usb/serial.h | 2 +- 25 files changed, 147 insertions(+), 73 deletions(-) -- 2.39.3