Commit Graph

229 Commits

Author SHA1 Message Date
Adrian Bunk
3824ba7df9 [PATCH] remove unused tmp_buf_sem's
tmp_buf_sem sems to be a common name for something completely unused...

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de> ("usb portion")
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-14 10:41:42 -08:00
Linus Torvalds
58cba4650a Merge git://git.kernel.org/pub/scm/linux/kernel/git/brodo/pcmcia-fixes-2.6 2006-01-12 14:00:47 -08:00
Linus Torvalds
bf785ee0ae Merge master.kernel.org:/home/rmk/linux-2.6-arm 2006-01-12 12:23:49 -08:00
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
Dominik Brodowski
f542ff6dd1 [PATCH] pcmcia: add new IDs for serial_cs.c
Add IDs for Sierra Aircard 55 CDMA 1xrtt Modem -- a CIS update is required
for this card.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2006-01-12 18:48:15 +01:00
Greg Ungerer
082f2c1cc7 [PATCH] m68knommu: set irq priority/level different for each ColdFire serial port
Set the hardware interrupt priority to a different value for each
attached ColdFire serial port.  According to the CPU documentation you
should not use the same combination of level/priority on more than one
device.  People have reported odd serial port behavior with them set the
same.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10 09:31:27 -08:00
Linus Torvalds
d936cfc720 Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus 2006-01-10 09:00:55 -08:00
Andrew Victor
1e6c9c2878 [ARM] 3242/2: AT91RM9200 support for 2.6 (Serial)
Patch from Andrew Victor

This patch adds support to the 2.6 kernel series for the Atmel
AT91RM9200 processor.

This patch is the Serial driver.

This version uses the newly re-written GPL'ed hardware headers.

Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-10 16:59:27 +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
Andrew Morton
6ed80991a2 [PATCH] tty-layer-buffering-revamp: jsm is broken
Looks like JSM will be uncompilable after the TTY layer rework is merged into
Linus's post-2.6.15 tree.

It was complex to fix - the maintainers were notified in September.

Cc: Wendy Xiong <wendyx@us.ltcfwd.linux.ibm.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10 08:01:57 -08:00
Ralf Baechle
29ce2c765c Update Yoichi Yuasa's email address.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-01-10 13:39:07 +00:00
Linus Torvalds
977127174a Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/pci-2.6 2006-01-09 18:41:42 -08:00
Linus Torvalds
3995f4c532 Merge master.kernel.org:/home/rmk/linux-2.6-arm 2006-01-09 15:09:30 -08:00
Linus Torvalds
0581445007 Merge master.kernel.org:/home/rmk/linux-2.6-serial 2006-01-09 15:09:03 -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
Aristeu Sergio Rozanski Filho
03929c76f3 [PATCH] ppc32: cpm_uart: fix xchar sending
while using SCC as uart and as serial console at same time I got this:

[  138.214258] Oops: kernel access of bad area, sig: 11 [#1]
[  138.218832] PREEMPT
[  138.221021] NIP: C0105C48 LR: C0105E60 SP: C03D5D10 REGS: c03d5c60 TRAP: 0300    Not tainted
[  138.229280] MSR: 00009032 EE: 1 PR: 0 FP: 0 ME: 1 IR/DR: 11
[  138.234713] DAR: 00000000, DSISR: C0000000
[  138.238745] TASK = c0349420[693] 'sh' THREAD: c03d4000
[  138.243754] Last syscall: 6
[  138.246402] GPR00: FEFFFFFF C03D5D10 C0349420 C01FB094 00000011 00000000 C1ECFBBC C01F24B0
[  138.254602] GPR08: FF002820 00000000 FF0028C0 00000000 19133615 A0CBCD5E 02000300 00000000
[  138.262804] GPR16: 00000000 01FF9E4C 00000000 7FA9A770 00000000 00000000 1003E2A8 00000000
[  138.271003] GPR24: 100562F4 7F9B6EF4 C0210000 C02A5338 C01FB094 00000000 C01FB094 C1F14574
[  138.279376] NIP [c0105c48] cpm_uart_tx_pump+0x4c/0x22c
[  138.284419] LR [c0105e60] cpm_uart_start_tx+0x38/0xb0
[  138.289361] Call trace:
[  138.291762]  [c0105e60] cpm_uart_start_tx+0x38/0xb0
[  138.296547]  [c010277c] uart_send_xchar+0x88/0x118
[  138.301244]  [c01029a0] uart_unthrottle+0x6c/0x138
[  138.305942]  [c00ece10] check_unthrottle+0x60/0x64
[  138.310641]  [c00ecec4] reset_buffer_flags+0xb0/0x138
[  138.315595]  [c00ecf64] n_tty_flush_buffer+0x18/0x78
[  138.320465]  [c00e81b0] tty_ldisc_flush+0x64/0x7c
[  138.325078]  [c010410c] uart_close+0xf0/0x2c8
[  138.329348]  [c00e9c48] release_dev+0x724/0x8d4
[  138.333790]  [c00e9e18] tty_release+0x20/0x3c
[  138.338061]  [c006e544] __fput+0x178/0x1e0
[  138.342076]  [c006c43c] filp_close+0x54/0xac
[  138.346261]  [c0002d90] ret_from_syscall+0x0/0x44
[  138.352386] note: sh[693] exited with preempt_count 2

a easy way to reproduce it is log into the system using ssh and do:
	cat >/dev/ttyCPM0
then, switch to minicom and write some stuff on it back to ssh, a control C
produce the oops

this happens because uart_close calls uart_shutdown which frees xmit.buf,
currently used by xchar sending in cpm_uart_tx_pump(), which seems wrong.

the attached patch fixes the oops and also fixes xchar sending.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-09 15:44:26 +11:00
Benjamin Herrenschmidt
cc5d0189b9 [PATCH] powerpc: Remove device_node addrs/n_addr
The pre-parsed addrs/n_addrs fields in struct device_node are finally
gone. Remove the dodgy heuristics that did that parsing at boot and
remove the fields themselves since we now have a good replacement with
the new OF parsing code. This patch also fixes a bunch of drivers to use
the new code instead, so that at least pmac32, pseries, iseries and g5
defconfigs build.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-09 14:53:55 +11:00
Russell King
0fec53a24a [ARM] Remove EPXA10DB machine support
EPXA10DB seems to be uncared for:
- the "PLD" code has never been merged
- no one has reported that this platform has been broken since
  at least 2.6.10
- interest seems to have dried up around March 2003.

Therefore, remove EPXA10DB support.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-08 22:37:46 +00:00
Dave Jones
a61c2d78ce [SERIAL] Make the number of UARTs registered configurable.
Also add a nr_uarts module option to the 8250 code to override
this, up to a maximum of CONFIG_SERIAL_8250_NR_UARTS

This should appease people who complain about a proliferation
of /dev/ttyS & /sysfs nodes whilst at the same time allowing
a single kernel image to support the rarer occasions of
lots of devices.

Signed-off-by: Dave Jones <davej@redhat.com>
2006-01-07 23:18:19 +00:00
Russell King
f61051cd2f [SERIAL] Fix clocal wakeup problem
Jim Alexander reported a problem where "if one calls open() in
blocking mode with CLOCAL off, the 8250.c driver under the 2.6
kernel (or at least 2.6.8 and 2.6.10) does not wake up the
blocked process when DCD is asserted."

Fix this by enabling modem status interrupts immediately before
we read the carrier detect status.

Thanks to Jim for reporting the problem and testing the fix.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-07 23:11:23 +00:00
Linus Torvalds
8995b161eb Merge master.kernel.org:/home/rmk/linux-2.6-arm 2006-01-07 10:45:22 -08:00
Linus Torvalds
cc918c7ab7 Merge master.kernel.org:/home/rmk/linux-2.6-serial 2006-01-07 10:44:22 -08:00
Russell King
f8ce25476d [ARM] Move asm/hardware/clock.h to linux/clk.h
This is needs to be visible to other architectures using the AMBA
bus and peripherals.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-07 16:15:52 +00:00
Russell King
123656d4cc Merge with Linus' kernel. 2006-01-07 14:40:05 +00:00
Russell King
a62c80e559 [ARM] Move AMBA include files to include/linux/amba/
Since the ARM AMBA bus is used on MIPS as well as ARM, we need
to make the bus available for other architectures to use.  Move
the AMBA include files from include/asm-arm/hardware/ to
include/linux/amba/

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-07 13:52:45 +00:00
Sylvain Munaut
d62de3aa8a [PATCH] ppc32/serial: Change mpc52xx_uart.c to use the Low Density Serial port major
Before this patch we were just using the "classic" /dev/ttySx devices.
However when another on the system is loaded that uses those (like drivers for
serial PCMCIA), that creates a conflict for the minors.  Therefore, we now use
/dev/ttyPSC[0:5] (note the 0-based numbering !) with some minors we've been
assigned in the "Low Density Serial port major"

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:33:30 -08:00
Sylvain Munaut
2d8179c0b7 [PATCH] ppc32/serial: Fix compiler errors with GCC 4.x in mpc52xx_uart.c
Signed-off-by: Wolfgang Denk <wd@denx.de>
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:33:30 -08:00
Dominik Brodowski
f8cfa618dc [PATCH] pcmcia: unify attach, EVENT_CARD_INSERTION handlers into one probe callback
Unify the EVENT_CARD_INSERTION and "attach" callbacks to one unified
probe() callback. As all in-kernel drivers are changed to this new
callback, there will be no temporary backwards-compatibility. Inside a
probe() function, each driver _must_ set struct pcmcia_device
*p_dev->instance and instance->handle correctly.

With these patches, the basic driver interface for 16-bit PCMCIA drivers
now has the classic four callbacks known also from other buses:

        int (*probe)            (struct pcmcia_device *dev);
        void (*remove)          (struct pcmcia_device *dev);

        int (*suspend)          (struct pcmcia_device *dev);
        int (*resume)           (struct pcmcia_device *dev);

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2006-01-06 00:03:24 +01:00
Dominik Brodowski
b463581154 [PATCH] pcmcia: remove dev_list from drivers
The linked list of devices managed by each PCMCIA driver is, in very most
cases, unused. Therefore, remove it from many drivers.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2006-01-06 00:03:20 +01:00
Dominik Brodowski
cc3b4866be [PATCH] pcmcia: unify detach, REMOVAL_EVENT handlers into one remove callback
Unify the "detach" and REMOVAL_EVENT handlers to one "remove" function.
Old functionality is preserved, for the moment.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2006-01-06 00:03:10 +01:00
Dominik Brodowski
98e4c28b7e [PATCH] pcmcia: new suspend core
Move the suspend and resume methods out of the event handler, and into
special functions. Also use these functions for pre- and post-reset, as
almost all drivers already do, and the remaining ones can easily be
converted.

Bugfix to include/pcmcia/ds.c
Signed-off-by: Andrew Morton <akpm@osdl.org>

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2006-01-05 23:59:02 +01:00
Andrew Morton
dd68e88c72 [SERIAL] 8520_pci: build fix
_INLINE_ went away.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-05 10:55:26 +00:00
Russell King
ea8874dc38 [SERIAL] Remove _INLINE_
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-04 19:43:24 +00:00
Russell King
45e2460192 [SERIAL] Move interrupt-time spinlocking inside serial8250_handle_port()
All call sites for serial8250_handle_port() acquired the port spinlock
and released it afterwards.  This is a needless duplication of code.
Move the spinlocking inside serial8250_handle_port().

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-04 19:19:06 +00:00
Russell King
50aec3b561 [SERIAL] Use uart_match_port() to find a matching port in find_port()
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-04 18:13:03 +00:00
Benjamin Herrenschmidt
1624f00334 [SERIAL] Fix matching of MMIO ports
The function uart_match_port() incorrectly compares the ioremap'd
virtual addresses of ports instead of the physical address to find
duplicate ports for MMIO based UARTs. This fixes it.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-04 18:09:44 +00:00
Gareth Howlett
26e92861be [SERIAL] Add support for more Connect Tech PCI serial boards
I've also fixed the sort-ordering comments on this naming convention.

Signed-off-by: Stuart MacDonald <stuartm@connecttech.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-04 17:00:42 +00:00
Russell King
2af7cd68f1 [Serial] Don't miss modem status changes
Reading the MSR register on 8250-compatible UARTs results in any
modem status interrupts being cleared.  To avoid missing any
status changes, arrange for get_mctrl() to read the current
status via check_modem_status(), which will process any pending
state changes for us.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-04 16:55:09 +00:00
Russell King
a8d3584a2d [ARM] Remove clk_use()/clk_unuse()
It seems that clk_use() and clk_unuse() are additional complexity
which isn't required anymore.  Remove them from the clock framework
to avoid the additional confusion which they cause, and update all
ARM machine types except for OMAP.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-03 18:41:37 +00:00
Erik Hovland
f02aa3f9a3 [ARM] 3216/1: indent and typo in drivers/serial/pxa.c
Patch from Erik Hovland

This patch provides two changes. An indent is supplied for an if/else clause so that it is more readable. An acronym is incorrectly typed as UER when it should be IER.

Signed-off-by: Erik Hovland <erik@hovland.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-12-30 15:57:35 +00:00
Russell King
a710ce0858 [SERIAL] Fix AMBA PL011 sysrq character handling
We only want the received character without the status bits for
sysrq handling.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-12-27 11:10:34 +00:00
Adrian Bunk
0b57ee9e55 [SPARC]: introduce a SPARC Kconfig symbol
Introduce a Kconfig symbol SPARC that is defined on both the sparc and
sparc64 architectures.

This symbol makes some dependencies more readable.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-12-22 23:09:54 -08:00
Dave Jones
c2cd6d3c12 [SERIAL] 8250_pci: Remove redundant assignment, and mark fallthrough.
Signed-off-by: Dave Jones <davej@redhat.com>
2005-12-07 18:11:26 +00:00
Arjan van de Ven
cb3592be27 [SERIAL] mark several serial tables const
This patch marks a few serial data structures const, moving them to
.rodata where they won't false-share cachelines with things that get
written to.

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-11-28 21:04:11 +00:00
Russell King
c889b89619 [SERIAL] imx: Fix missed platform_driver_unregister
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-11-21 17:05:21 +00:00
Linus Torvalds
8ee3f40267 Merge master.kernel.org:/home/rmk/linux-2.6-serial 2005-11-19 15:25:23 -08:00
Russell King
832f4ede79 [SERIAL] Remove unused variable in sa1100.c
Since the spinlock was removed from sa1100_start_tx(), the "flags"
variable becomes redundant.  Remove it.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-11-19 11:26:17 +00:00
Russell King
b63d4f0fb8 [SERIAL] Fix status reporting with PL011 serial driver
The receiver status register reports latched error conditions, which
must be cleared by writing to it.  However, the data register reports
unlatched conditions which are associated with the current character.
Use the data register to interpret error status rather than the RSR.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-11-19 11:10:35 +00:00
Matthew Wilcox
305f5167f1 [PARISC] Make Serial MUX depend on a specific bus type.
Depend on GSC, not PARISC.  Machines without GSC don't have a MUX.

Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2005-11-18 16:17:50 -05:00
Ryan Bradetich
a137ce8536 [PARISC] Define port->timeout to fix a long msleep in mux.c
This commit is in response to a bug reported by Vesa on the irc channel
a couple of weeks ago.

The bug was that the console would apparently hang (not return) while
using the mux console.

The root cause of this bug is that bash (with readline support) makes a
call to the tcsetattr() glibc function with the argument TCSADRAIN.  This
causes the serial core in the kernel use the uart_wait_until_sent() to be
called. This function verifies the mux transmit queue is empty or calls the
msleep_interruptable() with a calculated timeout value that is dependant
upon the port->timeout variable.

The real problem here is that the port->timeout was not defined so it
was defaulted to 0 and the timeout calculation performs the following
calculation:

char_time = (port->timeout - HZ/50) / port->fifosize;

where char_time is an unsigned long. Since the serial Mux does not use
interrupts, the msleep_interruptable() function waits until the timeout
has been reached ... and when the port->timeout < HZ/50 this timeout will
be a long time. (I have validated that the console will eventually
return ... but it takes quite a while for this to happen).

This patch simply sets the port->timeout on the Mux to HZ/50 to avoid
this long timeout period.

Signed-off-by: Ryan Bradetich <rbrad@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2005-11-17 16:38:28 -05:00