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path: root/drivers/serial/sunzilog.c
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2010-08-06of/device: Replace struct of_device with struct platform_deviceGrant Likely
of_device is just an alias for platform_device, so remove it entirely. Also replace to_of_device() with to_platform_device() and update comment blocks. This patch was initially generated from the following semantic patch, and then edited by hand to pick up the bits that coccinelle didn't catch. @@ @@ -struct of_device +struct platform_device Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Reviewed-by: David S. Miller <davem@davemloft.net>
2010-07-24of/platform: remove all of_bus_type and of_platform_bus_type referencesGrant Likely
Both of_bus_type and of_platform_bus_type are just #define aliases for the platform bus. This patch removes all references to them and switches to the of_register_platform_driver()/of_unregister_platform_driver() API for registering. Subsequent patches will convert each user of of_register_platform_driver() into plain platform_drivers without the of_platform_driver shim. At which point the of_register_platform_driver()/of_unregister_platform_driver() functions can be removed. Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: David S. Miller <davem@davemloft.net>
2010-06-28sparc/of: Move of_device fields into struct pdev_archdataGrant Likely
This patch moves SPARC architecture specific data members out of struct of_device and into the pdev_archdata structure. The reason for this change is to unify the struct of_device definition amongst all the architectures. It also remvoes the .sysdata, .slot, .portid and .clock_freq properties because they aren't actually used by anything. A subsequent patch will replace struct of_device entirely with struct platform_device and the of_platform support code will share common routines with the platform bus (but the bus instances themselves can remain separate). This patch also adds 'struct resources *resource' and num_resources to match the fields defined in struct platform_device. After this change, 'struct platform_device' can be used as a drop-in replacement for 'struct of_platform'. This change is in preparation for merging the of_platform_bus_type with the platform_bus_type. Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: David S. Miller <davem@davemloft.net> Cc: Stephen Rothwell <sfr@canb.auug.org.au>
2010-05-22Merge remote branch 'origin' into secretlab/next-devicetreeGrant Likely
Merging in current state of Linus' tree to deal with merge conflicts and build failures in vio.c after merge. Conflicts: drivers/i2c/busses/i2c-cpm.c drivers/i2c/busses/i2c-mpc.c drivers/net/gianfar.c Also fixed up one line in arch/powerpc/kernel/vio.c to use the correct node pointer. Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-05-22of: Remove duplicate fields from of_platform_driverGrant Likely
.name, .match_table and .owner are duplicated in both of_platform_driver and device_driver. This patch is a removes the extra copies from struct of_platform_driver and converts all users to the device_driver members. This patch is a pretty mechanical change. The usage model doesn't change and if any drivers have been missed, or if anything has been fixed up incorrectly, then it will fail with a compile time error, and the fixup will be trivial. This patch looks big and scary because it touches so many files, but it should be pretty safe. Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Sean MacLennan <smaclennan@pikatech.com>
2010-05-20sparc,sunzilog: Add console polling support for sunzilog serial driverJason Wessel
Allow kgdboc to work on sparc hardware with the Zilog serial chips. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Acked-by: David S. Miller <davem@davemloft.net>
2010-05-18of: Always use 'struct device.of_node' to get device node pointer.Grant Likely
The following structure elements duplicate the information in 'struct device.of_node' and so are being eliminated. This patch makes all readers of these elements use device.of_node instead. (struct of_device *)->node (struct dev_archdata *)->prom_node (sparc) (struct dev_archdata *)->of_node (powerpc & microblaze) Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2009-11-24serial: suncore: Fix RSC/LOM handling in sunserial_console_termios().David S. Miller
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>
2009-11-24serial: suncore: Add 'ignore_line' argument to sunserial_console_match().David S. Miller
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>
2009-09-19serial: move delta_msr_wait into the tty_portAlan Cox
This is used by various drivers not just serial and can be extracted as commonality Signed-off-by: Alan Cox <alan@linux.intel.com>
2009-09-19serial: kill off uart_infoAlan Cox
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>
2009-03-24serial: struct device - replace bus_id with dev_name(), dev_set_name()Kay Sievers
Cc: davem@davemloft.net Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
2008-08-31sparc: Annotate of_device_id arrays with const or __initdata.David S. Miller
As suggested by Stephen Rothwell. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-11sparc/drivers: use linux/of_device.h instead of asm/of_device.hStephen Rothwell
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-20ttydev: fix pamc_zilog for tty pointer moveStephen Rothwell
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>
2008-05-02serial: Fix sparc driver name strings.David S. Miller
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>
2008-04-26sparc: sunzilog.c remove unused argumentRobert Reif
Remove unused argument in function call. Signed-off-by: Robert Reif <reif@earthlink.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-24sparc: sunzilog uart orderRobert Reif
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>
2007-12-12[SERIAL] sparc: Infrastructure to fix section mismatch bugs.Martin Habets
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>
2007-08-26[SERIAL]: Fix 32-bit warnings in sunzilog.c and sunsu.cDavid S. Miller
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>
2007-07-20[SPARC]: Fix serial console device detection.David S. Miller
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>
2007-07-16[SERIAL]: Fix console write locking in sparc drivers.David S. Miller
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>
2007-05-29[SERIAL] sunzilog: section mismatch fixKrzysztof Helt
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>
2007-05-09[SERIAL] sunzilog: Interrupt enable before ISR handler installedMark Fortescue
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>
2007-02-14[PATCH] remove many unneeded #includes of sched.hTim Schmielau
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>
2006-12-31[SPARC64]: Fix of_iounmap() region release.David S. Miller
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>
2006-12-08[PATCH] tty: switch to ktermiosAlan Cox
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>
2006-10-11[SPARC32]: Fix sparc32 modpost warnings with sunzilogMartin Habets
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>
2006-10-10[PATCH] __iomem annotations in sunzilogAl Viro
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>
2006-10-05IRQ: Maintain regs pointer globally rather than passing to IRQ handlersDavid Howells
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)
2006-09-29[SERIAL] sunzilog: Mark sunzilog_init_hw as __devinit.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-08-23[SERIAL] sunzilog: Mirror the sunsab serial setup bug fix.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-07-21[SERIAL] sunzilog: Fix instance enumeration.David S. Miller
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[SERIAL] sunzilog: Remove duplicate IRQ registry in zs_probe().David S. Miller
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[SERIAL] sunzilog: Register IRQ after all devices have been probed.David S. Miller
Otherwise we will deref half-initialized channel pointers and crash in the interrupt handler. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-07-02[PATCH] irq-flags: serial: Use the new IRQF_ constantsThomas Gleixner
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>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-29[SERIAL] sun{su,zilog}: Add missing MODULE_*() niceties.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-29[SERIAL] sunzilog: Fix bugs in device deregristration.David S. Miller
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[SERIAL] sunzilog: Convert to of_driver.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-26[PATCH] devfs: Remove devfs support from the serial subsystemGreg Kroah-Hartman
Also fixes all serial drivers. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-23[SPARC64]: Convert central bus layer to in-kernel PROM device tree.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-20[SPARC]: Kill __irq_itoa().David S. Miller
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>
2006-03-22Merge master.kernel.org:/home/rmk/linux-2.6-serialLinus Torvalds
* 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
2006-03-20[SERIAL] kernel console should send CRLF not LFCRRussell King
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[SPARC] serial: Make sure sysfs nodes get named correctly.David S. Miller
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[SPARC64]: Prevent registering wrong serial console.David S. Miller
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>
2006-02-05[SERIAL] uart_port iotype member should use UPIO_*Russell King
Convert usage of SERIAL_IO_* to UPIO_*. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-10[PATCH] TTY layer buffering revampAlan Cox
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>
2005-10-10[SPARC64]: Fix oops on runlevel change with serial console.David S. Miller
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>