The tty layer uses tsw_busy to poll for busy/idle status of the transmitter
hardware during close() and tcdrain(). The ucom layer defines ULSR_TXRDY and
ULSR_TSRE bits for the line status register; when both are set, the
transmitter is idle. Not all chip drivers maintain those bits in the sc_lsr
field, and if the bits never get set the transmitter will always appear
busy, causing hangs in tcdrain().
These changes add a new sc_flag bit, UCOM_FLAG_LSRTXIDLE. When this flag is
set, ucom_busy() uses the lsr bits to return busy vs. idle state, otherwise
it always returns idle (which is effectively what happened before this
change because tsw_busy wasn't implemented).
For the uftdi chip driver, these changes stop masking out the tx idle bits
when processing the status register (because now they're useful), and it
calls ucom_use_lsr_txbits() to indicate the bits are maintained by the
driver and can be used by ucom_busy().
Differential Revision: https://reviews.freebsd.org/D9183
mutexes or using any callouts when active.
Trying to lock a mutex when KDB is active or the scheduler is stopped
can result in infinite wait loops. The same goes for calling callout
related functions which in turn lock mutexes.
If the USB controller at which a USB keyboard is connected is idle
when KDB is entered, polling the USB keyboard via USB will always
succeed. Else polling may fail depending on which state the USB
subsystem and USB interrupt handler is in. This is unavoidable unless
KDB can wait for USB interrupt threads to complete before stalling the
CPU(s).
Tested by: Bruce Evans <bde@freebsd.org>
MFC after: 4 weeks
rules prevent the USB serial module to be unloaded before any client
modules. This patch ensures that the "ucom_mtx" mutex is destroyed
last when doing a system uninit in a monotolith build aswell.
MFC after: 3 days
The NetBSD Foundation states "Third parties are encouraged to change the
license on any files which have a 4-clause license contributed to the
NetBSD Foundation to a 2-clause license."
This change removes clauses 3 and 4 from copyright / license blocks that
list The NetBSD Foundation as the only copyright holder.
Sponsored by: The FreeBSD Foundation
temporarily stores characters if the TTY buffer is full when
used a as a console. This can happen when a console is suspended.
Also properly do the flow stop signalling when this happens and
flow start when the condition changes back to normal again.
Bump __FreeBSD_version to force external kernel modules
to be recompiled. No kernel API changes.
MFC after: 1 week
Suggested by: ed @
"device_free_softc()" and "device_claim_softc()",
to allow USB serial drivers refcounting the softc.
These functions are used to grab the softc from
auto-free and to free the softc back to the correct
malloc type, respectivly.
Discussed with: jhb
MFC after: 2 weeks
Extend the callback table of UCOM to include a
"ucom_free" function pointer which is called when
all refs on a UCOM super structure is gone.
Implement various helper functions to handle
refcounting and draining on the UCOM super
structure.
Implement macro which can be used in device
drivers to avoid module unload before all
pending TTY references are gone.
The UCOM API is backwards compatible after this
change and device drivers require no changes
to function with this change. Only a recompilation
of UCOM device drivers is required. The FreeBSD
version has been bumped in that regard.
Discussed with: kib, ed
MFC after: 2 weeks
information through devd. My E220 now produces the notification (1 line):
+u3g0 at bus=1 hubaddr=1 port=0 devaddr=2 interface=0 \
vendor=0x12d1 product=0x1003 devclass=0x00 devsubclass=0x00 \
sernum="" release=0x0000 intclass=0xff intsubclass=0xff \
ttyname=U0 ttyports=2 on uhub0
Note: serial/ufoma and net/uhso still provide port number and tty name
(uhso only) information through sysctls, which should now be removed.
Reviewed by: hpselasky
- Fix the loop count on detach (causing a panic on detaching a serial
dongle).
- Increase a buffer in case some driver want extra long tty device names
(postfixing the purpose of the tty for example, e.g. u3g.ppp).
- hw.usb.ucom.cons_unit is now split into
hw.usb.ucom.cons_unit/...cons_subunit.
Note: The tunable/sysctl hw.usb.ucom.cons_unit needs to be reviewed if
a) a console was defined a USB serial devices, and a USB device with
more than 1 subunit is present, and this device is attached before the
device functioning as a console
or
b) a console was defined on a USB device with more than 1 subunit
Reviewed by: hps
MFC after: 2 weeks
