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path: root/drivers/serial/mux.c
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* Build fixes for struct pt_regs removalMatthew Wilcox2006-10-061-1/+1
| | | | Signed-off-by: Matthew Wilcox <matthew@wil.cx>
* [PATCH] ioremap balanced with iounmap for drivers/serial/mux.cAmol Lad2006-10-011-0/+2
| | | | | | | | | | ioremap must be balanced by an iounmap and failing to do so can result in a memory leak. Signed-off-by: Amol Lad <amol@verismonetworks.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>
* Remove obsolete #include <linux/config.h>Jörn Engel2006-06-301-1/+0
| | | | | Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* [PARISC] I/O-Space must be ioremap_nocache()'dHelge Deller2006-03-301-2/+2
| | | | | | | Addresses in F-space must be accessed uncached on most parisc machines. Signed-off-by: Helge Deller <deller@parisc-linux.org> Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
* [SERIAL] uart_port iotype member should use UPIO_*Russell King2006-02-051-1/+1
| | | | | | Convert usage of SERIAL_IO_* to UPIO_*. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [PATCH] TTY layer buffering revampAlan Cox2006-01-101-8/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [PARISC] Define port->timeout to fix a long msleep in mux.cRyan Bradetich2005-11-171-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [PARISC] Compile fixups for serial/mux.cRyan Bradetich2005-11-171-8/+4
| | | | | | | | | This patch does the following: * Fixes compiler warnings. * Replaces a __raw_readl call with the existing macro. Signed-off-by: Ryan Bradetich <rbrad@parisc-linux.org> Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
* [PARISC] Fix mux.c driverMatthew Wilcox2005-10-211-2/+5
| | | | | | | | | | | | Missing spin_lock_init() made the Mux driver hang on SMP systems. Fix up users of ->hpa to use ->hpa.start instead Remove warning in 8250_gsc.c by eliminating serial_line_nr Signed-off-by: Matthew Wilcox <willy@parisc-linux.org> Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
* [PARISC] Convert parisc_device to use struct resource for hpaMatthew Wilcox2005-10-211-1/+1
| | | | | | | | | | | | Convert pa_dev->hpa from an unsigned long to a struct resource. Signed-off-by: Matthew Wilcox <willy@parisc-linux.org> Fix up users of ->hpa to use ->hpa.start instead. Signed-off-by: Matthew Wilcox <willy@parisc-linux.org> Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
* [PARISC] Change the driver names so /sys/bus/parisc/drivers/ looks betterMatthew Wilcox2005-10-211-1/+1
| | | | | | | | | Make /sys/bus/parisc/drivers look better by cleaning up parisc_driver names. Signed-off-by: Matthew Wilcox <willy@parisc-linux.org> Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
* [SERIAL] Clean up and fix tty transmission start/stopingRussell King2005-08-311-6/+4
| | | | | | | | | | | | | | | | | | | | | | | 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>
* Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds2005-04-161-0/+539
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!
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