linux-toradex.git/drivers/tty/tty_ioctl.c, branch v4.1.10

tty: Re-add external interface for tty_set_termios()

2015-04-28T12:26:20+00:00

This is needed by Bluetooth hci_uart module to be able to change speed
of Bluetooth controller and local UART.

Signed-off-by: Frederic Danis 
Reviewed-by: Peter Hurley 
Cc: Marcel Holtmann 
Signed-off-by: Greg Kroah-Hartman

TTY: fix tty_wait_until_sent maximum timeout

2015-03-07T02:44:15+00:00

Currently tty_wait_until_sent may take up to twice as long as the
requested timeout while waiting for driver and hardware buffers to
drain.

Fix this by taking the remaining number of jiffies after waiting for
driver buffers to drain into account so that the timeout actually
becomes a maximum timeout as it is documented to be.

Note that this specifically implies tighter timings when closing a port
as a consequence of actually honouring the port closing-wait setting
for drivers relying on tty_wait_until_sent_from_close (e.g. via
tty_port_close_start).

Signed-off-by: Johan Hovold 
Reviewed-by: Peter Hurley 
Signed-off-by: Greg Kroah-Hartman

TTY: fix tty_wait_until_sent on 64-bit machines

2015-03-07T02:44:14+00:00

Fix overflow bug in tty_wait_until_sent on 64-bit machines, where an
infinite timeout (0) would be passed to the underlying tty-driver's
wait_until_sent-operation as a negative timeout (-1), causing it to
return immediately.

This manifests itself for example as tcdrain() returning immediately,
drivers not honouring the drain flags when setting terminal attributes,
or even dropped data on close as a requested infinite closing-wait
timeout would be ignored.

The first symptom  was reported by Asier LLANO who noted that tcdrain()
returned prematurely when using the ftdi_sio usb-serial driver.

Fix this by passing 0 rather than MAX_SCHEDULE_TIMEOUT (LONG_MAX) to the
underlying tty driver.

Note that the serial-core wait_until_sent-implementation is not affected
by this bug due to a lucky chance (comparison to an unsigned maximum
timeout), and neither is the cyclades one that had an explicit check for
negative timeouts, but all other tty drivers appear to be affected.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable 	# v2.6.12
Reported-by: ZIV-Asier Llano Palacios 
Signed-off-by: Johan Hovold 
Reviewed-by: Peter Hurley 
Signed-off-by: Greg Kroah-Hartman

tty: Remove external interface for tty_set_termios()

2015-02-02T18:11:28+00:00

tty_set_termios() is an internal helper intended for file scope use.

UART drivers which are capable of driving the RTS pin must
properly handle the tiocmset() method, regardless of termios settings.
A failure to do so is a UART driver bug and should be fixed there.
Do not use this interface to workaround UART driver bugs.

Cc: Johan Hedberg 
Cc: 
Signed-off-by: Peter Hurley 
Acked-by: Marcel Holtmann 
Signed-off-by: Greg Kroah-Hartman

tty: Call methods in modern style

2014-11-06T04:18:30+00:00

The use of older function ptr calling style, (*fn)(), makes static
analysis more error-prone; replace with modern fn() style.

Signed-off-by: Peter Hurley 
Signed-off-by: Greg Kroah-Hartman

tty: Move pty-specific set_termios() handling to pty driver

2014-11-06T00:34:36+00:00

Packet mode is unique to the pty driver; move the packet mode state
change code from the generic tty ioctl handler to the pty driver.

Signed-off-by: Peter Hurley 
Reviewed-by: Alan Cox 
Signed-off-by: Greg Kroah-Hartman

tty: WARN for attempted set_termios() of pty master

2014-11-06T00:34:36+00:00

The pty master's termios should never be set; currently, all code
paths which call the driver's set_termios() method ensure that the
pty slave's termios is being set.

Signed-off-by: Peter Hurley 
Reviewed-by: Alan Cox 
Signed-off-by: Greg Kroah-Hartman

tty: Hold termios_rwsem for tcflow(TCIxxx)

2014-09-24T04:19:36+00:00

While transmitting a START/STOP char for tcflow(TCION/TCIOFF), prevent
a termios change. Otherwise, a garbage in-band flow control char
may be sent, if the termios change overlaps the transmission setup.

Signed-off-by: Peter Hurley 
Signed-off-by: Greg Kroah-Hartman

tty: Move and rename send_prio_char() as tty_send_xchar()

2014-09-24T04:19:35+00:00

Relocate the file-scope function, send_prio_char(), as a global
helper tty_send_xchar(). Remove the global declarations for
tty_write_lock()/tty_write_unlock(), as these are file-scope only now.

Signed-off-by: Peter Hurley 
Signed-off-by: Greg Kroah-Hartman

tty: Serialize tcflow() with other tty flow control changes

2014-09-24T04:19:35+00:00

Use newly-introduced tty->flow_lock to serialize updates to
tty->flow_stopped (via tcflow()) and with concurrent tty flow
control changes from other sources.

Merge the storage for ->stopped and ->flow_stopped, now that both
flags are serialized by ->flow_lock.

The padding bits are necessary to force the compiler to allocate the
type specified; otherwise, gcc will ignore the type specifier and
allocate the minimum number of bytes necessary to store the bitfield.
In turn, this would allow Alpha EV4 and EV5 cpus to corrupt adjacent
byte storage because those cpus use RMW to store byte and short data.

gcc versions < 4.7.2 will also corrupt storage adjacent to bitfields
smaller than unsigned long on ia64, ppc64, hppa64 and sparc64, thus
requiring more than unsigned int storage (which would otherwise be
sufficient to workaround the Alpha non-atomic byte/short storage problem).

Signed-off-by: Peter Hurley 
Signed-off-by: Greg Kroah-Hartman