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* tty: move obsolete and broken tty drivers to drivers/staging/tty/Greg Kroah-Hartman2011-02-221-1560/+0
| | | | | | | | | | | | | | | | | | | As planned by Arnd Bergmann, this moves the following drivers to the drivers/staging/tty/ directory where they will be removed after 2.6.41 if no one steps up to claim them. epca epca ip2 istallion riscom8 serial167 specialix stallion Cc: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: now phase out the ioctl file pointer for goodAlan Cox2011-02-171-1/+1
| | | | | | | | | Only oddities here are a couple of drivers that bogusly called the ldisc helpers instead of returning -ENOIOCTLCMD. Fix the bug and the rest goes away. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tiocmset: kill the file pointer argumentAlan Cox2011-02-171-2/+2
| | | | | | | | Doing tiocmget was such fun we should do tiocmset as well for the same reasons Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tiocmget: kill off the passing of the struct fileAlan Cox2011-02-171-1/+1
| | | | | | | | | | We don't actually need this and it causes problems for internal use of this functionality. Currently there is a single use of the FILE * pointer. That is the serial core which uses it to check tty_hung_up_p. However if that is true then IO_ERROR is also already set so the check may be removed. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* riscom8: kill use of lock_kernelAlan Cox2010-08-101-6/+8
| | | | | | | | | | | | The riscom8 board uses lock_kernel to protect bits of the port setting ioctl logic. We can use the port mutex for this as the logic is internal and will also lock set versus open (a locking property that has been lost somewhere along the way) Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: Fix regressions in the char driver conversionAlan Cox2010-04-301-0/+1
| | | | | | | | | | | | | This forgot to update a field in the old char drivers. The fact nobody has basically noticed (except one mxser user) rather suggests most of these drivers could go into the bitbucket. Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Jiri Slaby <jirislaby@gmail.com> Cc: Dan Carpenter <error27@gmail.com> Cc: Andreas Pretzsch <apr@cn-eng.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: riscom8: switch to the tty_port_open APIAlan Cox2009-12-111-48/+41
| | | | | Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: riscom8, fix tty refcntJiri Slaby2009-09-191-1/+1
| | | | | | | | | | | Stanse found a tty refcnt leak on one fail path in rc_transmit. Fix that by jumping to the 'out' label. http://stanse.fi.muni.cz/ Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: riscom8, fix shutdown declarationJiri Slaby2009-09-191-2/+2
| | | | | | | | | | tty_port_ops.shutdown takes only one parameter: tty port. Remove the second one and use port->tty where needed instead. Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: riscom8 kref and tty_port_closeAlan Cox2009-09-191-72/+59
| | | | | | | We need to kref this driver in order to use port_close Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* riscom8: split open and close methods upAlan Cox2009-09-191-21/+26
| | | | | | | Moving towards a tty_port method for open/close Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* headers: smp_lock.h reduxAlexey Dobriyan2009-07-121-0/+1
| | | | | | | | | | | | | * Remove smp_lock.h from files which don't need it (including some headers!) * Add smp_lock.h to files which do need it * Make smp_lock.h include conditional in hardirq.h It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT This will make hardirq.h inclusion cheaper for every PREEMPT=n config (which includes allmodconfig/allyesconfig, BTW) Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* riscom8: Auto-load riscom8 module when device opened.Scott James Remnant2009-04-061-0/+2
| | | | | | | | | | | The riscom8 module is missing the char-major-48-* alias that would cause it to be auto-loaded when a device of that type is opened. This patch adds the alias. Signed-off-by: Scott James Remnant <scott@canonical.com> Signed-off-by: Tim Gardner <tim.gardner@canonical.com> Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: Remove some pointless castsAlan Cox2009-01-021-17/+17
| | | | | | | disc_data and driver_data are void * Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: Introduce some close helpers for portsAlan Cox2009-01-021-44/+5
| | | | | | | Again this is a lot of common code we can unify Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: Introduce a tty_port generic block_til_readyAlan Cox2009-01-021-85/+1
| | | | | | | | Start sucking more commonality out of the drivers into a single piece of core code. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: relock riscom8 using port locksAlan Cox2009-01-021-10/+20
| | | | | Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty_port: Add a port level carrier detect operationAlan Cox2009-01-021-25/+40
| | | | | | | | This is the first step to generalising the various pieces of waiting logic duplicated in all sorts of serial drivers. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* riscom8: Restore driver using new break functionalityAlan Cox2008-07-221-18/+9
| | | | | Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: add more tty_port fieldsAlan Cox2008-07-201-13/+11
| | | | | | | Move more bits into the tty_port structure Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* riscom8: remove bogus checksAlan Cox2008-07-201-24/+8
| | | | | | | | | Chris Malley posted a patch removing a NULL check in the riscom8 driver. Further analysis shows that even more of the tests are irrelevant so we can delete lots of stuff Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* riscom8: use tty_portAlan Cox2008-07-201-78/+67
| | | | | | | Switch riscom8 to use the new tty_port structure Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/char: replace remaining __FUNCTION__ occurrencesHarvey Harrison2008-04-301-2/+2
| | | | | | | | __FUNCTION__ is gcc-specific, use __func__ Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* riscom8: coding styleAlan Cox2008-04-301-340/+304
| | | | | | | Signed-off-by: Alan Cox <alan@redhat.com> Cc: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* riscom/rocket: switch to int put_char methodAlan Cox2008-04-301-3/+6
| | | | | | | Signed-off-by: Alan Cox <alan@redhat.com> Cc: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty/serial: lay the foundations for the next set of reworksAlan Cox2008-04-301-19/+19
| | | | | | | | | | | | | | | | | | | | | | | | - Stop drivers calling their own flush method indirectly, it obfuscates code and it will change soon anyway - A few more lock_kernel paths temporarily needed in some driver internal waiting code - Remove private put_char method that does a write call for one char - we have that anyway - Most but not yet all of the termios copy under lock fixing (some has other dependencies to follow) - Note a few locking bugs in drivers found in the process - Kill remaining [ab]users of TIOCG/SSOFTCAR in the driver, these must go to fix the termios locking Signed-off-by: Alan Cox <alan@redhat.com> Cc: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* riscom8: Prepare for BKL pushdownAlan Cox2008-04-301-14/+11
| | | | | | | | | | Push the locking down into a couple of functions that need it and remove bogus TIOCG/SSOFTCAR handling Signed-off-by: Alan Cox <alan@redhat.com> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* char: riscom, fix rc_board indexingJiri Slaby2008-03-131-1/+1
| | | | | | | | | | In riscom8_init_module, rc_board should be indexed by i, not by 0, otherwise the loop is useless. Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* riscom8: Fix hang on loadAlan Cox2008-03-101-6/+0
| | | | | | | | This has been around for a while but nobody reported it until recently. Resubmitting the fix as it's appropriate for 2.6.25 Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Char: riscom8, remove wakeup and hangup bottomhalvesJiri Slaby2008-02-071-47/+4
| | | | | | | | | | Both of them may be called directly from the code, don't add special code and variables and schedule a work for them. Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Char: riscom8, change rc_init_drivers prototypeJiri Slaby2008-02-071-1/+1
| | | | | | | | | | Let compiler decide if the rc_init_drivers function will be inlined and mark it as __init, because it's called only from __init function. Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* riscom8: fix SMP brokennessJeff Garzik2008-02-061-54/+93
| | | | | | | | | | | | | | | After analyzing the elements that save_flags/cli/sti/restore_flags were protecting, convert their usages to a global spinlock (the easiest and most obvious next-step). There were some usages of flags being intentionally cached, because the code already knew the state of interrupts. These have been taken into account. This allows us to remove CONFIG_BROKEN_ON_SMP. Completely untested. [akpm@linux-foundation.org: use DEFINE_SPINLOCK] Signed-off-by: Jeff Garzik <jgarzik@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/char/riscom8: clean up irq handlingJeff Garzik2007-10-231-11/+5
| | | | | | | | | | Make irq handling more efficient, by passing board pointer via request_irq() to our irq handler's dev_id argument. This eliminates a table lookup upon each interrupt, and eliminates an associated global variable (the table). Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* Char: riscom8, eliminate busy loopJiri Slaby2007-07-171-10/+2
| | | | | | | | riscom8, eliminate busy loop Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/char: use __set_current_state()Milind Arun Choudhary2007-05-081-1/+1
| | | | | | | | | use __set_current_state(TASK_*) instead of current->state = TASK_*, Signed-off-by: Milind Arun Choudhary <milindchoudhary@gmail.com> Cc: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] Char: tty_wakeup cleanupJiri Slaby2007-02-111-4/+1
| | | | | | | | | | | | | | tty_wakeup cleanup - remove wake_up_interruptible(&tty->write_wait) surrounding tty_wakup(tty); - substitute tty->ldisc.write_wakeup(tty) + wake_up() by tty_wakeup(tty); Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Acked-by: Tilman Schmidt <tilman@imap.cc> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] tty: switch to ktermiosAlan Cox2006-12-081-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] remove drivers/char/riscom8.c:baud_table[]Adrian Bunk2006-12-071-5/+0
| | | | | | | | | | | Commit c7bce3097c0f9bbed76ee6fd03742f2624031a45 removed all usages of baud_table[] but not the array itself. Spotted by the GNU C compiler. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] drivers/{char|isdn}: work_struct-induced breakageAl Viro2006-12-061-6/+6
| | | | | | | part 1 of fsck-knows-how-many Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Various drivers' irq handlers: kill dead code, needless castsJeff Garzik2006-10-061-4/+3
| | | | | | | | | | | | | | | | - Eliminate casts to/from void* - Eliminate checks for conditions that never occur. These typically fall into two classes: 1) Checking for 'dev_id == NULL', then it is never called with NULL as an argument. 2) Checking for invalid irq number, when the only caller (the system) guarantees the irq handler is called with the proper 'irq' number argument. Signed-off-by: Jeff Garzik <jeff@garzik.org>
* IRQ: Maintain regs pointer globally rather than passing to IRQ handlersDavid Howells2006-10-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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)
* [PATCH] char: kill unneeded memsetsJiri Slaby2006-10-041-9/+1
| | | | | | | | | | | | char, another tmp_buf cleanup No need to allocate one page as a side buffer. It's no more used. Clean this (de)allocs of this useless memory pages in char subtree. Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] const struct tty_operationsJeff Dike2006-10-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | As part of an SMP cleanliness pass over UML, I consted a bunch of structures in order to not have to document their locking. One of these structures was a struct tty_operations. In order to const it in UML without introducing compiler complaints, the declaration of tty_set_operations needs to be changed, and then all of its callers need to be fixed. This patch declares all struct tty_operations in the tree as const. In all cases, they are static and used only as input to tty_set_operations. As an extra check, I ran an i386 allyesconfig build which produced no extra warnings. 53 drivers are affected. I checked the history of a bunch of them, and in most cases, there have been only a handful of maintenance changes in the last six months. serial_core.c was the busiest one that I looked at. Signed-off-by: Jeff Dike <jdike@addtoit.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] serial: Fix up offenders peering at baud bits directlyAlan Cox2006-10-011-18/+4
| | | | | | | | | | | Stop some other people peering into the baud bits on their own and make them use the tty_get_baud_rate() helper as a preperation for the move to the new termios. Corrected dependancy previous one had on new termios structs Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] irq-flags: drivers/char: Use the new IRQF_ constantsThomas Gleixner2006-07-021-1/+1
| | | | | | | | | 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> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] devfs: Remove the tty_driver devfs_name field as it's no longer neededGreg Kroah-Hartman2006-06-261-1/+0
| | | | | | Also fixes all drivers that set this field. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] Remove MODULE_PARMRusty Russell2006-03-251-4/+4
| | | | | | | | | | MODULE_PARM was actually breaking: recent gcc version optimize them out as unused. It's time to replace the last users, which are generally in the most unloved drivers anyway. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] remove unused tmp_buf_sem'sAdrian Bunk2006-01-141-1/+0
| | | | | | | | 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>
* [PATCH] TTY layer buffering revampAlan Cox2006-01-101-26/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] drivers/char: Use ARRAY_SIZE macroTobias Klauser2006-01-101-4/+4
| | | | | | | | | Use ARRAY_SIZE macro instead of sizeof(x)/sizeof(x[0]) and remove duplicates of ARRAY_SIZE. Signed-off-by: Tobias Klauser <tklauser@nuerscht.ch> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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