linux.git/drivers/serial/serial_core.c, branch v2.6.24

serial: stop passing NULL to functions that expect data

2007-10-25T19:18:40+00:00

Earlier patches have removed the checking for old v new differences from the
USB drivers so we can now pass in a valid blank old termios so that we don't
to fill the drivers with magic hacks for console support

Signed-off-by: Alan Cox 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

serial: turn serial console suspend a boot rather than compile time option

2007-10-18T21:37:19+00:00

Currently, there's a CONFIG_DISABLE_CONSOLE_SUSPEND that allows one to stop
the serial console from being suspended when the rest of the machine goes
to sleep.  This is incredibly useful for debugging power management-related
things; however, having it as a compile-time option has proved to be
incredibly inconvenient for us (OLPC).  There are plenty of times that we
want serial console to not suspend, but for the most part we'd like serial
console to be suspended.

This drops CONFIG_DISABLE_CONSOLE_SUSPEND, and replaces it with a kernel
boot parameter (no_console_suspend).  By default, the serial console will
be suspended along with the rest of the system; by passing
'no_console_suspend' to the kernel during boot, serial console will remain
alive during suspend.

For now, this is pretty serial console specific; further fixes could be
applied to make this work for things like netconsole.

Signed-off-by: Andres Salomon 
Acked-by: "Rafael J. Wysocki" 
Acked-by: Pavel Machek 
Cc: Nigel Cunningham 
Cc: Russell King 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

wake up from a serial port

2007-10-16T16:42:50+00:00

Enable wakeup from serial ports, make it run-time configurable over sysfs,
e.g.,

echo enabled > /sys/devices/platform/serial8250.0/tty/ttyS0/power/wakeup

Requires

# CONFIG_SYSFS_DEPRECATED is not set

Following suggestions from Alan and Russell moved the may_wake_up checks
to serial_core.c. This time actually tested - it does even work. Could
someone, please, verify, that put_device after device_find_child is
correct?

Also would be nice to test with a Natsemi UART, that can wake up the system,
if such systems exist.

For this you just have to apply the patch below, issue the above "echo"
command to one of your Natsemi port, suspend and resume your system, and
verify that your Natsemi port still works.  If you are actually capable of
waking up the system from that port, would be nice to test that as well.

Signed-off-by: Guennadi Liakhovetski 
Cc: Alan Cox 
Cc: Russell King 
Cc: Kay Sievers 
Cc: Greg KH 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[SERIAL] Fix console initialisation ordering

2007-10-15T17:53:35+00:00

Ensure pm callback is called upon initialisation to place port in
correct power saving state.  Ensure console is initialised prior
to deciding whether to power down the port.

Signed-off-by: Russell King

serial: don't optimise away baud rate changes when BOTHER is used

2007-08-23T02:52:44+00:00

The uart_set_termios() function will bail out early without bothering to
touch the hardware, if it decides that nothing "relevant" has changed.
Unfortunately, its idea of "relevant" doesn't include c_[io]speed.  So if
the baud rate bits are BOTHER and you just change the speed, the change
gets optimised away.

This patch makes it ignore the old Bfoo bits in c_cflag and just check
whether c_ispeed and c_ospeed have changed.  Those integers are always set
appropriately for us by set_termios().

Signed-off-by: David Woodhouse 
Acked-by: Alan Cox 
Cc: Russell King 
Cc: Mariusz Kozlowski 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Use resource_size_t for serial port IO addresses

2007-07-24T19:24:58+00:00

At present, various parts of the serial code use unsigned long to define
resource addresses.  This is a problem, because some 32-bit platforms have
physical addresses larger than 32-bits, and have mmio serial uarts located
above the 4GB point.

This patch changes the type of mapbase in both struct uart_port and struct
plat_serial8250_port to resource_size_t, which can be configured to be 64
bits on such platforms.  The mapbase in serial_struct can't safely be
changed, because that structure is user visible.

Signed-off-by: David Gibson 
Signed-off-by: Josh Boyer 
Cc: Russell King 
Cc: Paul Mackerras 
Cc: Jason Wessel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

serial: assert DTR for serial console devices

2007-07-16T16:05:34+00:00

Some RS-232 devices require DTR to be asserted before they can be used.  DTR
is normally asserted in uart_startup() when the port is opened.  But we don't
actually open serial console ports, so assert DTR when the port is added.

BTW:
earlyprintk and early_uart are hard coded to set DTR/RTS.

rmk says

  The only issue I can think of is the possibility for an attached modem to
  auto-answer or maybe even auto-dial before the system is ready for it to do
  so.  Might have an undesirable cost implication for some running with such a
  setup.

  Apart from that, I can't think of any other side effect of this specific
  patch.

Signed-off-by: Yinghai Lu 
Acked-by: Russell King 
Cc: Andi Kleen 
Cc: Bjorn Helgaas 
Cc: Gerd Hoffmann 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Serial: serial_core, use pr_debug

2007-05-07T19:12:51+00:00

serial_core, use pr_debug

Signed-off-by: Jiri Slaby 
Cc: Russell King 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

serial: define FIXED_PORT flag for serial_core

2007-05-07T19:12:50+00:00

At present, the serial core always allows setserial in userspace to change the
port address, irq and base clock of any serial port.  That makes sense for
legacy ISA ports, but not for (say) embedded ns16550 compatible serial ports
at peculiar addresses.  In these cases, the kernel code configuring the ports
must know exactly where they are, and their clocking arrangements (which can
be unusual on embedded boards).  It doesn't make sense for userspace to change
these settings.

Therefore, this patch defines a UPF_FIXED_PORT flag for the uart_port
structure.  If this flag is set when the serial port is configured, any
attempts to alter the port's type, io address, irq or base clock with
setserial are ignored.

In addition this patch uses the new flag for on-chip serial ports probed in
arch/powerpc/kernel/legacy_serial.c, and for other hard-wired serial ports
probed by drivers/serial/of_serial.c.

Signed-off-by: David Gibson 
Cc: Russell King 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

serial driver PMC MSP71xx

2007-05-07T19:12:50+00:00

Serial driver patch for the PMC-Sierra MSP71xx devices.

There are three different fixes:

1 Fix for DesignWare APB THRE errata: In brief, this is a non-standard
  16550 in that the THRE interrupt will not re-assert itself simply by
  disabling and re-enabling the THRI bit in the IER, it is only re-enabled
  if a character is actually sent out.

  It appears that the "8250-uart-backup-timer.patch" in the "mm" tree
  also fixes it so we have dropped our initial workaround.  This patch now
  needs to be applied on top of that "mm" patch.

2 Fix for Busy Detect on LCR write: The DesignWare APB UART has a feature
  which causes a new Busy Detect interrupt to be generated if it's busy
  when the LCR is written.  This fix saves the value of the LCR and
  rewrites it after clearing the interrupt.

3 Workaround for interrupt/data concurrency issue: The SoC needs to
  ensure that writes that can cause interrupts to be cleared reach the UART
  before returning from the ISR.  This fix reads a non-destructive register
  on the UART so the read transaction completion ensures the previously
  queued write transaction has also completed.

Signed-off-by: Marc St-Jean 
Cc: Russell King 
Cc: Ralf Baechle 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds