Commit Graph

47 Commits

Author SHA1 Message Date
David S. Miller 457931de3b serial: suncore: Fix RSC/LOM handling in sunserial_console_termios().
RSC and LOM devices have fixed speed settings.

We already had some code to match and handle "rsc" named devices on
E250 systems, but we also have to handle 'rsc-console', 'rsc-control',
and 'lom-console'.

Also, in order to get this right regardless of what 'output-device'
happens to be, explicitly pass the UART device node pointer to this
routine.

Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-24 14:09:56 -08:00
David S. Miller 4e3533d05b serial: suncore: Add 'ignore_line' argument to sunserial_console_match().
This tells the logic to ignore the line match when deciding whether the
device is the OpenFirmware specified console device or not.

This is going to be used in the SU driver for rsc-console detection.

There is probably a better way to handle this, but this is the least
intrusive solution for now which we can validate won't break any other
cases.

Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-24 14:03:34 -08:00
Alan Cox bdc04e3174 serial: move delta_msr_wait into the tty_port
This is used by various drivers not just serial and can be extracted
as commonality

Signed-off-by: Alan Cox <alan@linux.intel.com>
2009-09-19 13:13:31 -07:00
Alan Cox ebd2c8f6d2 serial: kill off uart_info
We moved this into uart_state, now move the fields out of the separate
structure and kill it off.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:28 -07:00
Kay Sievers 65a212dd71 serial: struct device - replace bus_id with dev_name(), dev_set_name()
Cc: davem@davemloft.net
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
2009-03-24 16:38:21 -07:00
David S. Miller fd098316ef sparc: Annotate of_device_id arrays with const or __initdata.
As suggested by Stephen Rothwell.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-31 01:23:17 -07:00
Stephen Rothwell c6ed413ddc sparc/drivers: use linux/of_device.h instead of asm/of_device.h
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-11 14:30:53 -07:00
Stephen Rothwell 2f7a697a13 ttydev: fix pamc_zilog for tty pointer move
Today's linux-next build (sparc64 defconfig) failed like this:

drivers/serial/sunhv.c: In function `receive_chars':
drivers/serial/sunhv.c:188: error: structure has no member named `tty'
drivers/serial/sunsu.c: In function `receive_chars':
drivers/serial/sunsu.c:314: error: structure has no member named `tty'
drivers/serial/sunsab.c: In function `receive_chars':
drivers/serial/sunsab.c:121: error: structure has no member named `tty'

I applied the following patch (which, again, may not be correct).

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-20 17:12:35 -07:00
David S. Miller 32039f4954 serial: Fix sparc driver name strings.
They were all "serial" so if multiple of these drivers registered,
we'd trigger sysfs directory creation errors:

[    1.695793] proc_dir_entry 'serial' already registered
[    1.695839] Call Trace:
[    1.831891]  [00000000004f2534] create_proc_entry+0x7c/0x98
[    1.833608]  [00000000004f3a58] proc_tty_register_driver+0x40/0x70
[    1.833663]  [0000000000594700] tty_register_driver+0x1fc/0x208
[    1.835371]  [00000000005aade4] uart_register_driver+0x134/0x16c
[    1.841762]  [00000000005ac274] sunserial_register_minors+0x34/0x68
[    1.841818]  [00000000007db2a4] sunsu_init+0xf8/0x150
[    1.867697]  [00000000007c62a4] kernel_init+0x190/0x330
[    1.939147]  [0000000000426cf8] kernel_thread+0x38/0x48
[    1.939198]  [00000000006a0d90] rest_init+0x18/0x5c

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-02 05:22:51 -07:00
Robert Reif 3ade11601f sparc: sunzilog.c remove unused argument
Remove unused argument in function call.

Signed-off-by: Robert Reif <reif@earthlink.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-26 23:10:19 -07:00
Robert Reif 227739bf4c sparc: sunzilog uart order
I have a sparcstation 20 clone with a lot of on board serial ports.
The serial core code assumes that uarts are assigned contiguously
and that may not be the case when there are multiple zs devices
present.  This patch insures that uart chips are placed in front of
keyboard/mouse chips in the port table.

ffd37420: ttyS0 at MMIO 0xf1100000 (irq = 44) is a zs (ESCC)
Console: ttyS0 (SunZilog zs0)
console [ttyS0] enabled
ffd37420: ttyS1 at MMIO 0xf1100004 (irq = 44) is a zs (ESCC)
ffd37500: Keyboard at MMIO 0xf1000000 (irq = 44) is a zs
ffd37500: Mouse at MMIO 0xf1000004 (irq = 44) is a zs
ffd3c5c0: ttyS2 at MMIO 0xf1100008 (irq = 44) is a zs (ESCC)
ffd3c5c0: ttyS3 at MMIO 0xf110000c (irq = 44) is a zs (ESCC)
ffd3c6a0: ttyS4 at MMIO 0xf1100010 (irq = 44) is a zs (ESCC)
ffd3c6a0: ttyS5 at MMIO 0xf1100014 (irq = 44) is a zs (ESCC)
ffd3c780: ttyS6 at MMIO 0xf1100018 (irq = 44) is a zs (ESCC)
ffd3c780: ttyS7 at MMIO 0xf110001c (irq = 44) is a zs (ESCC)

Signed-off-by: Robert Reif <reif@earthlink.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-24 03:37:51 -07:00
Martin Habets 58d784a5c7 [SERIAL] sparc: Infrastructure to fix section mismatch bugs.
This patch against 2.6.23 sparc-2.6.git contains a number of minor
cleanups of the sparc serial drivers.  Initially I fixed this build
warning:

WARNING: vmlinux.o(.text+0x107a2c): Section mismatch: reference to .init.text:add_preferred_console (between 'sunserial_console_match' and 'sunserial_console_termios')

which is done by declaring sunserial_console_match() as __init.  This
resulted in build warnings on sunserial_current_minor.  To resolve
these the variable was changed so it is no longer global, and to hide
operations on it inside 2 new functions. These functions handle the
UART minor handling code that is common to all sparc serial drivers.

These changes allowed to clean up the uart counters in all the sparc
serial drivers, and the administration of minor device numbers.

Lastly, sunserial_console_termios() does not need to be exported since
it is only called from non-modular code.

Sadly, the following build warning still exists:

WARNING: vmlinux.o(__ksymtab+0x2910): Section mismatch: reference to .init.text:sunserial_console_match (between '__ksymtab_sunserial_console_match' and '__ksymtab_sunserial_unregister_minors')

This could be resolved by not exporting sunserial_console_match(), but
this is not possible at the moment because it is being called from
modular code. On the other hand, this is a bogus warning since it
comes from a ksymtab section.

Signed-off-by: Martin Habets <errandir_news@mph.eclipse.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-12-12 07:36:34 -08:00
David S. Miller 4f1296a516 [SERIAL]: Fix 32-bit warnings in sunzilog.c and sunsu.c
resource_size_t can be either a u64 or a u32, and we can't
really know for sure, so when printing such a value out
always use long-long printf formatting and cast the argument
to that type.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-08-26 18:49:11 -07:00
David S. Miller c73fcc846c [SPARC]: Fix serial console device detection.
The current scheme works on static interpretation of text names, which
is wrong.

The output-device setting, for example, must be resolved via an alias
or similar to a full path name to the console device.

Paths also contain an optional set of 'options', which starts with a
colon at the end of the path.  The option area is used to specify
which of two serial ports ('a' or 'b') the path refers to when a
device node drives multiple ports.  'a' is assumed if the option
specification is missing.

This was caught by the UltraSPARC-T1 simulator.  The 'output-device'
property was set to 'ttya' and we didn't pick upon the fact that this
is an OBP alias set to '/virtual-devices/console'.  Instead we saw it
as the first serial console device, instead of the hypervisor console.

The infrastructure is now there to take advantage of this to resolve
the console correctly even in multi-head situations in fbcon too.

Thanks to Greg Onufer for the bug report.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-20 16:59:26 -07:00
David S. Miller f3c681c028 [SERIAL]: Fix console write locking in sparc drivers.
Mirror the logic in 8250 for proper console write locking
when SYSRQ is triggered or an OOPS is in progress.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-16 04:05:28 -07:00
Krzysztof Helt 9977e390dd [SERIAL] sunzilog: section mismatch fix
This patch fixes section mismatch warnings in the sunzilog driver.

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-05-29 02:49:17 -07:00
Mark Fortescue 7cc5c8559c [SERIAL] sunzilog: Interrupt enable before ISR handler installed
This patch changes the interrupt enable sequence for the sunzilog driver 
so that interrupts are not enabled untill after the interrupt handler has 
been installed. If this is not done, some SS1 and SS2 sun4c systems panic 
on un-handled interrupt before the handler gets installed preventing boot.

It also adds in support for the ESCC version of the zilog chips. The
changes mean that the FIFO will be enabled for ESCC versions of the
SCC UART. My interpretation of the SCC manual and the existing interrupt
handler code is that it sould be able to make good use of the FIFO without
issues.

Signed-off-by: Mark Fortescue <mark@mtfhpc.demon.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-05-09 13:49:04 -07:00
Tim Schmielau cd354f1ae7 [PATCH] remove many unneeded #includes of sched.h
After Al Viro (finally) succeeded in removing the sched.h #include in module.h
recently, it makes sense again to remove other superfluous sched.h includes.
There are quite a lot of files which include it but don't actually need
anything defined in there.  Presumably these includes were once needed for
macros that used to live in sched.h, but moved to other header files in the
course of cleaning it up.

To ease the pain, this time I did not fiddle with any header files and only
removed #includes from .c-files, which tend to cause less trouble.

Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
configs in arch/arm/configs on arm.  I also checked that no new warnings were
introduced by the patch (actually, some warnings are removed that were emitted
by unnecessarily included header files).

Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14 08:09:54 -08:00
David S. Miller e3a411a3df [SPARC64]: Fix of_iounmap() region release.
We need to pass in the resource otherwise we cannot
release the region properly.  We must know whether it is
an I/O or MEM resource.

Spotted by Eric Brower.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-31 14:06:05 -08:00
Alan Cox 606d099cdd [PATCH] tty: switch to ktermios
This is the grungy swap all the occurrences in the right places patch that
goes with the updates.  At this point we have the same functionality as
before (except that sgttyb() returns speeds not zero) and are ready to
begin turning new stuff on providing nobody reports lots of bugs

If you are a tty driver author converting an out of tree driver the only
impact should be termios->ktermios name changes for the speed/property
setting functions from your upper layers.

If you are implementing your own TCGETS function before then your driver
was broken already and its about to get a whole lot more painful for you so
please fix it 8)

Also fill in c_ispeed/ospeed on init for most devices, although the current
code will do this for you anyway but I'd like eventually to lose that extra
paranoia

[akpm@osdl.org: bluetooth fix]
[mp3@de.ibm.com: sclp fix]
[mp3@de.ibm.com: warning fix for tty3270]
[hugh@veritas.com: fix tty_ioctl powerpc build]
[jdike@addtoit.com: uml: fix ->set_termios declaration]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Acked-by: Peter Oberparleiter <oberpar@de.ibm.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 08:28:57 -08:00
Martin Habets eba8cefc78 [SPARC32]: Fix sparc32 modpost warnings with sunzilog
Fix this 2.6.19-rc1 build warnings from modpost:

WARNING: vmlinux - Section mismatch: reference to .init.text:sunzilog_console_setup from .data between 'sunzilog_console' (at offset 0x8394) and 'devices_subsys'

Signed-off-by: Martin Habets <errandir_news@mph.eclipse.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-10-11 23:56:53 -07:00
Al Viro 48343273e8 [PATCH] __iomem annotations in sunzilog
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-10 15:37:20 -07:00
David Howells 7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00
David S. Miller fbe96f92b3 [SERIAL] sunzilog: Mark sunzilog_init_hw as __devinit.
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-29 16:12:43 -07:00
David S. Miller b8b99e857d [SERIAL] sunzilog: Mirror the sunsab serial setup bug fix.
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-08-23 15:53:39 -07:00
David S. Miller 8a84eb164c [SERIAL] sunzilog: Fix instance enumeration.
Just do a linear enumeration so that we handle sun4d systems
correctly.  As a consequence, eliminate the hard coded keyboard and
mouse channel line values, use the CONS_{KEYB,MS} flags instead.

Also, report the keyboard/mouse Zilog channels just like the uart ones
do.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-07-21 14:18:25 -07:00
David S. Miller b77d35b722 [SERIAL] sunzilog: Remove duplicate IRQ registry in zs_probe().
We do it now in sunzilog_init() after all devices have been
probed.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-07-21 14:18:22 -07:00
David S. Miller 67e23a1e60 [SERIAL] sunzilog: Register IRQ after all devices have been probed.
Otherwise we will deref half-initialized channel pointers
and crash in the interrupt handler.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-07-21 14:18:08 -07:00
Thomas Gleixner 40663cc7f1 [PATCH] irq-flags: serial: Use the new IRQF_ constants
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-02 13:58:53 -07:00
Jörn Engel 6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
David S. Miller 9efc3715f7 [SERIAL] sun{su,zilog}: Add missing MODULE_*() niceties.
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-29 16:37:48 -07:00
David S. Miller 4fa97dcf9d [SERIAL] sunzilog: Fix bugs in device deregristration.
1) Need to unregister 2 ports per of_device.
2) Need to of_iounmap() 1 mapping per of_device.
3) Need to free up the IRQ only after all devices
   have been unregistered.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-29 16:37:44 -07:00
David S. Miller 3676463178 [SERIAL] sunzilog: Convert to of_driver.
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-29 16:37:42 -07:00
Greg Kroah-Hartman aa4148cfc7 [PATCH] devfs: Remove devfs support from the serial subsystem
Also fixes all serial drivers.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-26 12:25:05 -07:00
David S. Miller cecc4e9222 [SPARC64]: Convert central bus layer to in-kernel PROM device tree.
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-23 23:15:32 -07:00
David S. Miller c6387a48cf [SPARC]: Kill __irq_itoa().
This ugly hack was long overdue to die.

It was a way to print out Sparc interrupts in a more freindly format,
since IRQ numbers were arbitrary opaque 32-bit integers which vectored
into PIL levels.  These 32-bit integers were not necessarily in the
0-->NR_IRQS range, but the PILs they vectored to were.

The idea now is that we will increase NR_IRQS a little bit and use a
virtual<-->real IRQ number mapping scheme similar to PowerPC.

That makes this IRQ printing hack irrelevant, and furthermore only a
handful of drivers actually used __irq_itoa() making it even less
useful.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-20 01:21:29 -07:00
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
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
David S. Miller f5deb807b8 [SPARC] serial: Make sure sysfs nodes get named correctly.
Because we play this trick where we use ttyS? in increasing minor
numbers for different sunfoo.c drivers, we have to inform the TTY
layer of this.

Do so by setting the tty->name_base appropriately.

Probably there should be a generic way to do this in the serial core,
but for now...

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:13:47 -08:00
David S. Miller 1ddb7c98d4 [SPARC64]: Prevent registering wrong serial console.
If the console is not for a particular Sun serial
controller, set the drv->cons to NULL.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:12:42 -08:00
Russell King 9b4a161777 [SERIAL] uart_port iotype member should use UPIO_*
Convert usage of SERIAL_IO_* to UPIO_*.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-02-05 10:48:10 +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
David S. Miller b8df110fea [SPARC64]: Fix oops on runlevel change with serial console.
Incorrect uart_write_wakeup() calls cause reference to a
NULL tty pointer in sunsab and sunzilog serial drivers.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-10 20:43:22 -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
William Lee Irwin III 3761657853 [SPARC]: sunzilog warning fixes
From: William Lee Irwin III <wli@holomorphy.com>

This small patch silences some iomem-related warnings in sunzilog.c by
declaring mapped_addr as void __iomem * and inserting a cast in one case.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-24 20:06:18 -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