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
sys/dev/usb/serial/uplcom.c:543:29: error: implicit conversion from 'int' to 'int8_t' (aka 'signed char') changes value from 192 to -64 [-Werror,-Wconstant-conversion]
if (uplcom_pl2303_do(udev, UT_READ_VENDOR_DEVICE, UPLCOM_SET_REQUEST, 0x8484, 0, 1)
~~~~~~~~~~~~~~~~ ^~~~~~~~~~~~~~~~~~~~~
sys/dev/usb/usb.h:179:53: note: expanded from macro 'UT_READ_VENDOR_DEVICE'
#define UT_READ_VENDOR_DEVICE (UT_READ | UT_VENDOR | UT_DEVICE)
~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~
This is because UT_READ is 0x80, so the int8_t argument is wrapped to a
negative value. Fix this by using uint8_t instead.
Reviewed by: imp, hselasky
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D7776
The hardware delivers ns16550-compatible status bits, which is what the
usb_serial code expects, so no need for translation, no need for a local
variable to hold a temporary lsr result.
Previously the polarity was for TTL levels, which are the reverse of RS-232.
Also add handling of the UART_PPS_INVERT_PULSE option bit in the sysctl
value, the same as was recently added to uart(4), so that people using TTL
level connections can request a logical inverting of the signal.
Use the named constants from the new dev/uart/uart_ppstypes.h for the pps
capture modes and option bits.
tables. Some drivers needed some slight re-arrangement of declarations
to accommodate this. Change the USB pnp tables slightly to allow
better compatibility with the system by moving linux driver info from
start of each entry to the end. All other PNP tables in the system
have the per-device flags and such at the end of the elements rather
that at the beginning.
Differential Review: https://reviews.freebsd.org/D3458
The ftdi chip itself has a "get bitmode" command that doesn't actually
return the current bitmode, just a snapshot of the gpio lines. The chip
apparently has no way to provide the current bitmode.
This implements the functionality at the driver level. The driver starts
out assuming the chip is in UART mode (which it will be, coming out of
reset) and keeps track of every successful set-bitmode operation so that
it can always return the current mode with UFTDIIOC_GET_BITMODE.
interface without breaking ABI or API compatibility with existing drivers.
The existing data structures used to communicate between the kernel and
driver portions of PPS processing contain no spare/padding fields and no
flags field or other straightforward mechanism for communicating changes
in the structures or behaviors of the code. This makes it difficult to
MFC new features added to the PPS facility. ABI compatibility is
important; out-of-tree drivers in module form are known to exist. (Note
that the existing api_version field in the pps_params structure must
contain the value mandated by RFC 2783 and any RFCs that come along after.)
These changes introduce a pair of abi-version fields which are filled in
by the driver and the kernel respectively to indicate the interface
version. The driver sets its version field before calling the new
pps_init_abi() function. That lets the kernel know how much of the
pps_state structure is understood by the driver and it can avoid using
newer fields at the end of the structure that it knows about if the driver
is a lower version. The kernel fills in its version field during the init
call, letting the driver know what features and data the kernel supports.
To implement the new version information in a way that is backwards
compatible with code from before these changes, the high bit of the
lightly-used 'kcmode' field is repurposed as a flag bit that indicates the
driver is aware of the abi versioning scheme. Basically if this bit is
clear that indicates a "version 0" driver and if it is set the driver_abi
field indicates the version.
These changes also move the recently-added 'mtx' field of pps_state from
the middle to the end of the structure, and make the kernel code that uses
this field conditional on the driver being abi version 1 or higher. It
changes the only driver currently supplying the mtx field, usb_serial, to
use pps_init_abi().
Reviewed by: hselasky@
Huawei. It might appear as if the firmware is allocating memory blocks
according to the USB transfer size and if there is initially a lot of
data, like at the answering machine prompt, it simply dies without any
apparent reason. The simple workaround for this is to force a zero
length packet at hardware level after every 512 bytes of data. This
will force the other side to use smaller memory blocks aswell.
MFC after: 1 week
