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path: root/drivers/char/rtc.c
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2006-10-09[RTC] Consistently use of tabs for formatting.Ralf Baechle
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[PATCH] remove unnecessary barrier in rtc_get_rtc_timeSteven Rostedt
Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-25[PATCH] rtc: lockdep fix/workaroundPeter Zijlstra
BUG: warning at kernel/lockdep.c:1816/trace_hardirqs_on() (Not tainted) [<c04051ee>] show_trace_log_lvl+0x58/0x171 [<c0405802>] show_trace+0xd/0x10 [<c040591b>] dump_stack+0x19/0x1b [<c043abee>] trace_hardirqs_on+0xa2/0x11e [<c06143c3>] _spin_unlock_irq+0x22/0x26 [<c0541540>] rtc_get_rtc_time+0x32/0x176 [<c0419ba4>] hpet_rtc_interrupt+0x92/0x14d [<c0450f94>] handle_IRQ_event+0x20/0x4d [<c0451055>] __do_IRQ+0x94/0xef [<c040678d>] do_IRQ+0x9e/0xbd [<c0404a49>] common_interrupt+0x25/0x2c DWARF2 unwinder stuck at common_interrupt+0x25/0x2c Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-12[PATCH] lockdep: HPET/RTC fixIngo Molnar
Joseph Fannin reported that hpet_rtc_interrupt() enables hardirqs in irq context: [ 25.628000] [<c014af4e>] trace_hardirqs_on+0xce/0x200 [ 25.628000] [<c036cf21>] _spin_unlock_irq+0x31/0x70 [ 25.628000] [<c0296584>] rtc_get_rtc_time+0x44/0x1a0 [ 25.628000] [<c01198bb>] hpet_rtc_interrupt+0x21b/0x280 [ 25.628000] [<c0161141>] handle_IRQ_event+0x31/0x70 [ 25.628000] [<c0162d37>] handle_edge_irq+0xe7/0x210 [ 25.628000] [<c0106192>] do_IRQ+0x92/0x120 [ 25.628000] [<c0104121>] common_interrupt+0x25/0x2c the call of rtc_get_rtc_time() is highly suspect. At a minimum we need the patch below to save/restore hardirq state. Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Joseph Fannin <jfannin@gmail.com> Cc: John Stultz <johnstul@us.ibm.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10[PATCH] char/rtc: Handle memory-mapped chips properlyMaciej W. Rozycki
Handle memory-mapped chips properly, needed for example on DECstations. This support was in Linux 2.4 but for some reason got lost in 2.6. This patch is taken directly from the linux-mips repository. [akpm@osdl.org: cleanup] Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Martin Michlmayr <tbm@cyrius.com> Cc: Paul Gortmaker <penguin@muskoka.com> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03[PATCH] make more file_operation structs staticArjan van de Ven
Mark the static struct file_operations in drivers/char as const. Making them const prevents accidental bugs, and moves them to the .rodata section so that they no longer do any false sharing; in addition with the proper debug option they are then protected against corruption.. [akpm@osdl.org: build fix] Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-02[PATCH] irq-flags: drivers/char: 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> 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>
2006-06-23[SPARC64]: Use in-kernel PROM tree for EBUS and ISA.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>
2006-01-11[PATCH] Allow reading CMOS day of week registerAlan Cox
Someone wanted access to this usually unused (and unused by Linux) value for the day of week. Existing kernels have the field in the struct but return 0 always. This updates the kernel to fill in the field. The usual case of 'not set' conveniently is 0. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07[PATCH] Fix wrong irq enable via rtc_control()Takashi Iwai
rtc_control() may be called in the interrupt context in ALSA rtc-timer driver. The patch fixes the wrong irq enable in rtc.c, and also fixes the possible race of bit flags. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2005-09-05[RTC]: Use SA_SHIRQ in sparc specific code.David S. Miller
Based upon a report from Jason Wever. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-05[PATCH] rtc: msleep() cannot be used from interruptPetr Vandrovec
Since the beginning of July my Opteron box was randomly crashing and being rebooted by hardware watchdog. Today it finally did it in front of me, and this patch will hopefully fix it. The problem is that at the end of June (the 28th, to be exact: commit 47f176fdaf8924bc83fddcf9658f2fd3ef60d573, "[PATCH] Using msleep() instead of HZ") rtc_get_rtc_time was converted to use msleep() instead of busy waiting. But rtc_get_rtc_time is used by hpet_rtc_interrupt, and scheduling is not allowed during interrupt. So I'm reverting this part of original change, replacing msleep() back with busy loop. The original code was busy waiting for up to 20ms, but on my hardware in the worst case update-in-progress bit was asserted for at most 363 passes through loop (on 2GHz dual Opteron), much less than even one jiffie, not even talking about 20ms. So I changed code to just wait only as long as necessary. Otherwise when RTC was set to generate 8192Hz timer, it stopped doing anything for 20ms (160 pulses were skipped!) from time to time, and this is rather suboptimal as far as I can tell. Signed-off-by: Petr Vandrovec <vandrove@vc.cvut.cz> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-28[PATCH] Using msleep() instead of HZLuca Falavigna
Use msleep() in a few places. Signed-off-by: Luca Falavigna <dktrkranz@gmail.com> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Jeff Garzik <jgarzik@pobox.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
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!