linux.git/drivers/usb/serial/generic.c, branch v3.0

USB: serial: handle Data Carrier Detect changes

2011-01-23T02:53:26+00:00

Alan's commit 335f8514f200e63d689113d29cb7253a5c282967 introduced
.carrier_raised function in several drivers.  That also means
tty_port_block_til_ready can now suspend the process trying to open the serial
port when Carrier Detect is low and put it into tty_port.open_wait queue.  We
need to wake up the process when Carrier Detect goes high and trigger TTY
hangup when CD goes low.

Some of the devices do not report modem status line changes, or at least we
don't understand the status message, so for those we remove .carrier_raised
again.

Signed-off-by: Libor Pechacek 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input

2010-08-28T20:55:31+00:00

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: pxa27x_keypad - remove input_free_device() in pxa27x_keypad_remove()
  Input: mousedev - fix regression of inverting axes
  Input: uinput - add devname alias to allow module on-demand load
  Input: hil_kbd - fix compile error
  USB: drop tty argument from usb_serial_handle_sysrq_char()
  Input: sysrq - drop tty argument form handle_sysrq()
  Input: sysrq - drop tty argument from sysrq ops handlers

USB: serial: export symbol usb_serial_generic_disconnect

2010-08-24T03:50:16+00:00

This is needed by the ssu100 driver to use this function.

Signed-off-by: Bill Pemberton 
Signed-off-by: Greg Kroah-Hartman

USB: drop tty argument from usb_serial_handle_sysrq_char()

2010-08-21T07:37:39+00:00

Since handle_sysrq() does not take tty as argument anymore we can
drop it from usb_serial_handle_sysrq_char() as well.

Acked-by: Alan Cox 
Acked-by: Jason Wessel 
Acked-by: Greg Kroah-Hartman 
Signed-off-by: Dmitry Torokhov

Input: sysrq - drop tty argument form handle_sysrq()

2010-08-21T07:34:45+00:00

Sysrq operations do not accept tty argument anymore so no need to pass
it to us.

[Stephen Rothwell : fix build breakage in drm code
 caused by sysrq using bool but not including linux/types.h]

[Sachin Sant : fix build breakage in s390 keyboadr
 driver]

Acked-by: Alan Cox 
Acked-by: Jason Wessel 
Acked-by: Greg Kroah-Hartman 
Signed-off-by: Dmitry Torokhov

USB: serial: fix stalled writes

2010-08-10T21:35:45+00:00

As David VomLehn points out, it was possible to receive an interrupt
before clearing the free-urb flag which could lead to the urb being
incorrectly marked as busy.

For the same reason, move tx_bytes accounting so that it will never be
negative.

Note that the free-flags set and clear operations do not need any
additional locking as they are manipulated while USB_SERIAL_WRITE_BUSY
is set.

Reported-by: David VomLehn 
Tested-by: David VomLehn 
Signed-off-by: Johan Hovold 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

USB: serial: add special case for processing of empty read urbs

2010-05-20T20:21:48+00:00

Return immediately from generic process_read_urb if urb is empty.

Signed-off-by: Johan Hovold 
Signed-off-by: Greg Kroah-Hartman

USB: serial: remove multi-urb write from generic driver

2010-05-20T20:21:42+00:00

Remove multi-urb write from the generic driver and simplify the
prepare_write_buffer prototype:

	int (*prepare_write_buffer)(struct usb_serial_port *port,
						void *dest, size_t size);

The default implementation simply fills dest with data from port write
fifo but drivers can override it if they need to process the outgoing
data (e.g. add headers).

Turn ftdi_sio into a generic fifo-based driver, which lowers CPU usage
significantly for small writes while retaining maximum throughput.

Signed-off-by: Johan Hovold 
Signed-off-by: Greg Kroah-Hartman

USB: serial: reimplement generic fifo-based writes

2010-05-20T20:21:42+00:00

Reimplement fifo-based writes in the generic driver using a multiple
pre-allocated urb scheme.

In contrast to multi-urb writes, no allocations (of urbs or buffers) are
made during run-time and there is less pressure on the host stack
queues as currently only two urbs are used (implementation is generic
and can handle more than two urbs as well, though).

Initial tests using ftdi_sio show that the implementation achieves the
same (maximum) throughput at high baudrates as multi-urb writes. The CPU
usage is much lower than for multi-urb writes for small write requests
and only slightly higher for large (e.g. 2k) requests (due to extra copy
via fifo?).

Also outperforms multi-urb writes for small write requests on an
embedded arm-9 system, where multi-urb writes are CPU-bound at high
baudrates (perf reveals that a lot of time is spent in the host stack
enqueue function -- could perhaps be a bug as well).

Keeping the original write_urb, buffer and flag for now as there are
other drivers depending on them.

Signed-off-by: Johan Hovold 
Signed-off-by: Greg Kroah-Hartman

USB: serial: generalise write buffer preparation

2010-05-20T20:21:35+00:00

Generalise write buffer preparation.

This allows for drivers to manipulate (e.g. add headers) to bulk out
data before it is sent.

This adds a new function pointer to usb_serial_driver:

int (*prepare_write_buffer)(struct usb_serial_port *port,
		void **dest, size_t size, const void *src, size_t count);

The function is generic and can be used with either kfifo-based or
multi-urb writes:

If *dest is NULL the implementation should allocate dest.
If src is NULL the implementation should use the port write fifo.

If not set, a generic implementation is used which simply uses memcpy or
kfifo_out.

Signed-off-by: Johan Hovold 
Signed-off-by: Greg Kroah-Hartman