Commit Graph

13 Commits

Author SHA1 Message Date
Alexey Dobriyan
7f927fcc2f [PATCH] Typo fixes
Fix a lot of typos.  Eyeballed by jmc@ in OpenBSD.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 09:16:08 -08:00
Linus Torvalds
9d8f057acb Merge master.kernel.org:/home/rmk/linux-2.6-serial
* master.kernel.org:/home/rmk/linux-2.6-serial:
  [SERIAL] Merge avlab serial board entries in parport_serial
  [SERIAL] kernel console should send CRLF not LFCR
2006-03-22 17:33:12 -08:00
Atsushi Nemoto
83485f826b [PATCH] serial: serial_txx9 driver update
Update the serial_txx9 driver.

 * More strict check in verify_port.  Cleanup.
 * Do not insert a char caused previous overrun.
 * Fix some spin_locks.
 * Do not call uart_add_one_port for absent ports.

Also, this patch removes a BROKEN tag from Kconfig.  This driver has been
marked as BROKEN by removal of uart_register_port, but it has been solved
already on Sep 2005.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-22 07:53:55 -08:00
Russell King
d358788f3f [SERIAL] kernel console should send CRLF not LFCR
Glen Turner reported that writing LFCR rather than the more
traditional CRLF causes issues with some terminals.

Since this aflicts many serial drivers, extract the common code
to a library function (uart_console_write) and arrange for each
driver to supply a "putchar" function.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-03-20 20:00:09 +00:00
Arjan van de Ven
f392ecfa12 [SERIAL] turn serial semaphores into mutexes
Turn several drivers/serial/ semaphores-used-as-mutex into mutexes

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-12 18:44:32 +00:00
Alan Cox
33f0f88f1c [PATCH] TTY layer buffering revamp
The API and code have been through various bits of initial review by
serial driver people but they definitely need to live somewhere for a
while so the unconverted drivers can get knocked into shape, existing
drivers that have been updated can be better tuned and bugs whacked out.

This replaces the tty flip buffers with kmalloc objects in rings. In the
normal situation for an IRQ driven serial port at typical speeds the
behaviour is pretty much the same, two buffers end up allocated and the
kernel cycles between them as before.

When there are delays or at high speed we now behave far better as the
buffer pool can grow a bit rather than lose characters. This also means
that we can operate at higher speeds reliably.

For drivers that receive characters in blocks (DMA based, USB and
especially virtualisation) the layer allows a lot of driver specific
code that works around the tty layer with private secondary queues to be
removed. The IBM folks need this sort of layer, the smart serial port
people do, the virtualisers do (because a virtualised tty typically
operates at infinite speed rather than emulating 9600 baud).

Finally many drivers had invalid and unsafe attempts to avoid buffer
overflows by directly invoking tty methods extracted out of the innards
of work queue structs. These are no longer needed and all go away. That
fixes various random hangs with serial ports on overflow.

The other change in here is to optimise the receive_room path that is
used by some callers. It turns out that only one ldisc uses receive room
except asa constant and it updates it far far less than the value is
read. We thus make it a variable not a function call.

I expect the code to contain bugs due to the size alone but I'll be
watching and squashing them and feeding out new patches as it goes.

Because the buffers now dynamically expand you should only run out of
buffering when the kernel runs out of memory for real.  That means a lot of
the horrible hacks high performance drivers used to do just aren't needed any
more.

Description:

tty_insert_flip_char is an old API and continues to work as before, as does
tty_flip_buffer_push() [this is why many drivers dont need modification].  It
does now also return the number of chars inserted

There are also

tty_buffer_request_room(tty, len)

which asks for a buffer block of the length requested and returns the space
found.  This improves efficiency with hardware that knows how much to
transfer.

and tty_insert_flip_string_flags(tty, str, flags, len)

to insert a string of characters and flags

For a smart interface the usual code is

    len = tty_request_buffer_room(tty, amount_hardware_says);
    tty_insert_flip_string(tty, buffer_from_card, len);

More description!

At the moment tty buffers are attached directly to the tty.  This is causing a
lot of the problems related to tty layer locking, also problems at high speed
and also with bursty data (such as occurs in virtualised environments)

I'm working on ripping out the flip buffers and replacing them with a pool of
dynamically allocated buffers.  This allows both for old style "byte I/O"
devices and also helps virtualisation and smart devices where large blocks of
data suddenely materialise and need storing.

So far so good.  Lots of drivers reference tty->flip.*.  Several of them also
call directly and unsafely into function pointers it provides.  This will all
break.  Most drivers can use tty_insert_flip_char which can be kept as an API
but others need more.

At the moment I've added the following interfaces, if people think more will
be needed now is a good time to say

 int tty_buffer_request_room(tty, size)

Try and ensure at least size bytes are available, returns actual room (may be
zero).  At the moment it just uses the flipbuf space but that will change.
Repeated calls without characters being added are not cumulative.  (ie if you
call it with 1, 1, 1, and then 4 you'll have four characters of space.  The
other functions will also try and grow buffers in future but this will be a
more efficient way when you know block sizes.

 int tty_insert_flip_char(tty, ch, flag)

As before insert a character if there is room.  Now returns 1 for success, 0
for failure.

 int tty_insert_flip_string(tty, str, len)

Insert a block of non error characters.  Returns the number inserted.

 int tty_prepare_flip_string(tty, strptr, len)

Adjust the buffer to allow len characters to be added.  Returns a buffer
pointer in strptr and the length available.  This allows for hardware that
needs to use functions like insl or mencpy_fromio.

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: John Hawkes <hawkes@sgi.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10 08:01:59 -08:00
Richard Knutsson
93b47684f6 [PATCH] drivers/*rest*: Replace pci_module_init() with pci_register_driver()
Replace obsolete pci_module_init() with pci_register_driver().

Signed-off-by: Richard Knutsson <ricknu-0@student.ltu.se>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-09 12:13:23 -08:00
Ralf Baechle
f5ee56cc18 [PATCH] txx9 serial update
Support for the new RBHMA4500 eval board for the TX4938.  General update
from the 8250 ancestor of this driver.  Replace use of deprecated
interfaces.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Acked-by: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09 13:57:27 -07:00
Russell King
b129a8ccd5 [SERIAL] Clean up and fix tty transmission start/stoping
The start_tx and stop_tx methods were passed a flag to indicate
whether the start/stop was from the tty start/stop callbacks, and
some drivers used this flag to decide whether to ask the UART to
immediately stop transmission (where the UART supports such a
feature.)

There are other cases when we wish this to occur - when CTS is
lowered, or if we change from soft to hard flow control and CTS
is inactive.  In these cases, this flag was false, and we would
allow the transmitter to drain before stopping.

There is really only one case where we want to let the transmitter
drain before disabling, and that's when we run out of characters
to send.

Hence, re-jig the start_tx and stop_tx methods to eliminate this
flag, and introduce new functions for the special "disable and
allow transmitter to drain" case.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-08-31 10:12:14 +01:00
Russell King
c5f4644e6c [PATCH] Serial: Adjust serial locking
This patch changes the way serial ports are locked when getting modem
status.  This change is necessary because we will need to atomically
read the modem status and take action depending on the CTS status.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-06-29 09:42:38 +01:00
Russell King
05ab301463 [PATCH] Serial: Add uart_insert_char()
Add uart_insert_char(), which handles inserting characters into the
flip buffer.  This helper function handles the correct semantics
for handling overrun in addition to inserting normal characters.

Signed-off-by: Russell King <rmk@arm.linux.org.uk>
2005-05-09 23:21:59 +01:00
Pavel Machek
0370affeec [PATCH] fix u32 vs. pm_message_t in drivers/
-rc2-mm1 still contains few places where u32 and pm_message_t.  This fixes
drivers/serial [should change no code].

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16 15:25:35 -07:00
Linus Torvalds
1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00