- 07 9月, 2008 1 次提交
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由 Pawel MOLL 提交于
This patch clarifies usage of irq_chip->startup() callback: 1. The "if (startup) startup(); else enabled();" code in setup_irq() is unnecessary, as startup() falls back to enabled() via default callbacks, set by irq_chip_set_defaults(). 2. When using set_irq_chained_handler() the startup() was never called, which is not good at all... Fixed. And again - when startup() is not defined the call will fall back to enable() than to unmask() via default callbacks. Signed-off-by: NPawel Moll <pawel.moll@st.com> Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 22 8月, 2008 1 次提交
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由 Anton Vorontsov 提交于
When DEBUG_SHIRQ is selected, a spurious IRQ is issued before the setup_irq() initializes the desc->depth. An IRQ handler may call disable_irq_nosync(), but then setup_irq() will overwrite desc->depth, and upon enable_irq() we'll catch this WARN: ------------[ cut here ]------------ Badness at kernel/irq/manage.c:180 NIP: c0061ab8 LR: c0061f10 CTR: 00000000 REGS: cf83be50 TRAP: 0700 Not tainted (2.6.27-rc3-23450-g74919b0) MSR: 00021032 <ME,IR,DR> CR: 22042022 XER: 20000000 TASK = cf829100[5] 'events/0' THREAD: cf83a000 GPR00: c0061f10 cf83bf00 cf829100 c038e674 00000016 00000000 cf83bef8 00000038 GPR08: c0298910 00000000 c0310d28 cf83a000 00000c9c 1001a1a8 0fffe000 00800000 GPR16: ffffffff 00000000 007fff00 00000000 007ffeb0 c03320a0 c031095c c0310924 GPR24: cf8292ec cf807190 cf83a000 00009032 c038e6a4 c038e674 cf99b1cc c038e674 NIP [c0061ab8] __enable_irq+0x20/0x80 LR [c0061f10] enable_irq+0x50/0x70 Call Trace: [cf83bf00] [c038e674] irq_desc+0x630/0x9000 (unreliable) [cf83bf10] [c0061f10] enable_irq+0x50/0x70 [cf83bf30] [c01abe94] phy_change+0x68/0x108 [cf83bf50] [c0046394] run_workqueue+0xc4/0x16c [cf83bf90] [c0046834] worker_thread+0x74/0xd4 [cf83bfd0] [c004ab7c] kthread+0x48/0x84 [cf83bff0] [c00135e0] kernel_thread+0x44/0x60 Instruction dump: 4e800020 3d20c031 38a94214 4bffffcc 9421fff0 7c0802a6 93e1000c 7c7f1b78 90010014 8123001c 2f890000 409e001c <0fe00000> 80010014 83e1000c 38210010 That trace corresponds to this line: WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq); The patch fixes the problem by moving the SHIRQ code below the setup_irq(). Unfortunately we can't easily move the SHIRQ code inside the setup_irq(), since it grabs a spinlock, so to prvent a 'real' IRQ from interfere us we should disable that IRQ. p.s. The driver in question is drivers/net/phy/phy.c. Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 06 8月, 2008 1 次提交
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由 David Brownell 提交于
While I'm glad to finally see the hole fixed whereby passing an invalid IRQ trigger type to request_irq() would be ignored, the current diagnostic isn't quite useful. Fixed by also listing the trigger type which was rejected. Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net> Acked-by: NUwe Kleine-König <Uwe.Kleine-Koenig@digi.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 27 7月, 2008 1 次提交
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由 Arjan van de Ven 提交于
Replace a printk+WARN_ON() by a WARN(); this increases the chance of the string making it into the bugreport (ie: it goes inside the ---[ cut here ]--- section) Signed-off-by: NArjan van de Ven <arjan@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 26 7月, 2008 1 次提交
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由 Arjan van de Ven 提交于
Replace a printk+WARN_ON() by a WARN(); this increases the chance of the string making it into the bugreport (ie: it goes inside the ---[ cut here ]--- section) Signed-off-by: NArjan van de Ven <arjan@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 25 7月, 2008 1 次提交
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由 Uwe Kleine-König 提交于
set_type returns an int indicating success or failure, but up to now setup_irq ignores that. In my case this resulted in a machine hang: gpio-keys requested IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING, but arm/ns9xxx can only trigger on one direction so set_type didn't touch the configuration which happens do default to a level sensitiveness and returned -EINVAL. setup_irq ignored that and unmasked the irq. This resulted in an endless triggering of the gpio-key interrupt service routine which effectively killed the machine. With this patch applied setup_irq propagates the error to the caller. Note that before in the case chip && !chip->set_type && !chip->name a NULL pointer was feed to printk. This is fixed, too. Signed-off-by: NUwe Kleine-König <Uwe.Kleine-Koenig@digi.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 24 7月, 2008 1 次提交
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由 Uwe Kleine-König 提交于
Since 15a647eb set_irq_wake returned -ENXIO if another device had it already enabled. Zero is the right value to return in this case. Moreover the change to desc->status was not reverted if desc->chip->set_wake returned an error. Signed-off-by: NUwe Kleine-König <Uwe.Kleine-Koenig@digi.com> Acked-by: NDavid Brownell <dbrownell@users.sourceforge.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Andrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 10 7月, 2008 1 次提交
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由 Thomas Gleixner 提交于
In http://bugzilla.kernel.org/show_bug.cgi?id=9580 it was pointed out that the desc->chip checks are extraneous. In fact these are left overs from early development and can be removed safely. Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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- 05 6月, 2008 1 次提交
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由 Max Krasnyansky 提交于
Current IRQ affinity interface does not provide a way to set affinity for the IRQs that will be allocated/activated in the future. This patch creates /proc/irq/default_smp_affinity that lets users set default affinity mask for the newly allocated IRQs. Changing the default does not affect affinity masks for the currently active IRQs, they have to be changed explicitly. Updated based on Paul J's comments and added some more documentation. Signed-off-by: NMax Krasnyansky <maxk@qualcomm.com> Cc: pj@sgi.com Cc: a.p.zijlstra@chello.nl Cc: tglx@linutronix.de Cc: rdunlap@xenotime.net Cc: mingo@elte.hu Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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- 02 5月, 2008 1 次提交
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由 Thomas Gleixner 提交于
Uwe Kleine-Koenig has some strange hardware where one of the shared interrupts can be asserted during boot before the appropriate driver loads. Requesting the shared irq line from another driver result in a spurious interrupt storm which finally disables the interrupt line. I have seen similar behaviour on resume before (the hardware does not work anymore so I can not verify). Change the spurious disable logic to increment the disable depth and mark the interrupt with an extra flag which allows us to reenable the interrupt when a new driver arrives which requests the same irq line. In the worst case this will disable the irq again via the spurious trap, but there is a decent chance that the new driver is the one which can handle the already asserted interrupt and makes the box usable again. Eric Biederman said further: This case also happens on a regular basis in kdump kernels where we deliberately don't shutdown the hardware before starting the new kernel. This patch should reduce the need for using irqpoll in that situation by a small amount. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Tested-and-Acked-by: NUwe Kleine-König <Uwe.Kleine-Koenig@digi.com>
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- 29 4月, 2008 1 次提交
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由 Robert P. J. Day 提交于
Following an experimental deletion of the unnecessary directive #include <linux/slab.h> from the header file <linux/percpu.h>, these files under kernel/ were exposed as needing to include one of <linux/slab.h> or <linux/gfp.h>, so explicit includes were added where necessary. Signed-off-by: NRobert P. J. Day <rpjday@crashcourse.ca> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 30 1月, 2008 1 次提交
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由 Ingo Molnar 提交于
these bugs are harder to find than they seem, a stackdump helps. make it dependent on CONFIG_DEBUG_SHIRQ so that people can turn it off if it annoys them. Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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- 24 10月, 2007 1 次提交
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由 Herbert Xu 提交于
As it is some callers of synchronize_irq rely on memory barriers to provide synchronisation against the IRQ handlers. For example, the tg3 driver does tp->irq_sync = 1; smp_mb(); synchronize_irq(); and then in the IRQ handler: if (!tp->irq_sync) netif_rx_schedule(dev, &tp->napi); Unfortunately memory barriers only work well when they come in pairs. Because we don't actually have memory barriers on the IRQ path, the memory barrier before the synchronize_irq() doesn't actually protect us. In particular, synchronize_irq() may return followed by the result of netif_rx_schedule being made visible. This patch (mostly written by Linus) fixes this by using spin locks instead of memory barries on the synchronize_irq() path. Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au> Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 17 10月, 2007 1 次提交
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由 David Woodhouse 提交于
Andy Gospodarek pointed out that because we return in the middle of the free_irq() function, we never actually do call the IRQ handler that just got deregistered. This should fix it, although I expect Andrew will want to convert those 'return's to 'break'. That's a separate change though. Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org> Cc: Andy Gospodarek <andy@greyhouse.net> Cc: Fernando Luis Vzquez Cao <fernando@oss.ntt.co.jp> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 31 8月, 2007 1 次提交
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由 Jarek Poplawski 提交于
Mariusz Kozlowski reported lockdep's warning: > ================================= > [ INFO: inconsistent lock state ] > 2.6.23-rc2-mm1 #7 > --------------------------------- > inconsistent {in-hardirq-W} -> {hardirq-on-W} usage. > ifconfig/5492 [HC0[0]:SC0[0]:HE1:SE1] takes: > (&tp->lock){+...}, at: [<de8706e0>] rtl8139_interrupt+0x27/0x46b [8139too] > {in-hardirq-W} state was registered at: > [<c0138eeb>] __lock_acquire+0x949/0x11ac > [<c01397e7>] lock_acquire+0x99/0xb2 > [<c0452ff3>] _spin_lock+0x35/0x42 > [<de8706e0>] rtl8139_interrupt+0x27/0x46b [8139too] > [<c0147a5d>] handle_IRQ_event+0x28/0x59 > [<c01493ca>] handle_level_irq+0xad/0x10b > [<c0105a13>] do_IRQ+0x93/0xd0 > [<c010441e>] common_interrupt+0x2e/0x34 ... > other info that might help us debug this: > 1 lock held by ifconfig/5492: > #0: (rtnl_mutex){--..}, at: [<c0451778>] mutex_lock+0x1c/0x1f > > stack backtrace: ... > [<c0452ff3>] _spin_lock+0x35/0x42 > [<de8706e0>] rtl8139_interrupt+0x27/0x46b [8139too] > [<c01480fd>] free_irq+0x11b/0x146 > [<de871d59>] rtl8139_close+0x8a/0x14a [8139too] > [<c03bde63>] dev_close+0x57/0x74 ... This shows that a driver's irq handler was running both in hard interrupt and process contexts with irqs enabled. The latter was done during free_irq() call and was possible only with CONFIG_DEBUG_SHIRQ enabled. This was fixed by another patch. But similar problem is possible with request_irq(): any locks taken from irq handler could be vulnerable - especially with soft interrupts. This patch fixes it by disabling local interrupts during handler's run. (It seems, disabling softirqs should be enough, but it needs more checking on possible races or other special cases). Reported-by: NMariusz Kozlowski <m.kozlowski@tuxland.pl> Signed-off-by: NJarek Poplawski <jarkao2@o2.pl> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 23 8月, 2007 1 次提交
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由 Andrew Morton 提交于
If we're going to run the handler from free_irq() then we must do it with local irq's disabled. Otherwise lockdep complains that the handler is taking irq-safe spinlocks in a non-irq-safe fashion. Cc: Ingo Molnar <mingo@elte.hu> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 09 5月, 2007 1 次提交
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由 Ahmed S. Darwish 提交于
An irqaction structure won't be added to an IRQ descriptor irqaction list if it doesn't agree with other irqactions on the IRQF_PERCPU flag. Don't check for this flag to change IRQ descriptor `status' for every irqaction added to the list, Doing the check only for the first irqaction added is enough. Signed-off-by: NAhmed S. Darwish <darwish.07@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 17 2月, 2007 2 次提交
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由 Thomas Gleixner 提交于
Provide funtions to: - check, whether an interrupt can set the affinity - pin the interrupt to a given cpu Necessary for the ability to setup clocksources more flexible (e.g. use the different HPET channels per CPU) [akpm@osdl.org: alpha build fix] Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NIngo Molnar <mingo@elte.hu> Cc: john stultz <johnstul@us.ibm.com> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Thomas Gleixner 提交于
Add a flag so we can prevent the irq balancing of an interrupt. Move the bits, so we have room for more :) Necessary for the ability to setup clocksources more flexible (e.g. use the different HPET channels per CPU) Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NIngo Molnar <mingo@elte.hu> Cc: john stultz <johnstul@us.ibm.com> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 15 2月, 2007 1 次提交
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由 Thomas Gleixner 提交于
The obsolete SA_xxx interrupt flags have been used despite the scheduled removal. Fixup the remaining users. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Acked-by: NIngo Molnar <mingo@elte.hu> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Jeff Garzik <jeff@garzik.org> Cc: Wim Van Sebroeck <wim@iguana.be> Cc: Roland Dreier <rolandd@cisco.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: James Bottomley <James.Bottomley@steeleye.com> Cc: Greg KH <greg@kroah.com> Cc: Dave Airlie <airlied@linux.ie> Cc: James Simmons <jsimmons@infradead.org> Cc: "Antonino A. Daplas" <adaplas@pol.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 13 2月, 2007 2 次提交
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由 Alan Cox 提交于
The problem is various drivers legally validly and sensibly try to claim IRQs but the kernel insists on vomiting forth a giant irrelevant debugging spew when the types clash. Edit kernel/irq/manage.c go down to mismatch: in setup_irq() and ifdef out the if clause that checks for mismatches. It'll then just do the right thing and work sanely. For the current -mm kernel this will do the trick (and moves it into shared irq debugging as in debug mode the info spew is useful). I've had a variant of this in my private tree for some time as I got fed up on the mess on boxes where old legacy IRQs get reused. Signed-off-by: NAlan Cox <alan@redhat.com> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Woodhouse 提交于
Drivers registering IRQ handlers with SA_SHIRQ really ought to be able to handle an interrupt happening before request_irq() returns. They also ought to be able to handle an interrupt happening during the start of their call to free_irq(). Let's test that hypothesis.... [bunk@stusta.de: Kconfig fixes] Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org> Cc: Arjan van de Ven <arjan@infradead.org> Signed-off-by: NJesper Juhl <jesper.juhl@gmail.com> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NAdrian Bunk <bunk@stusta.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 12 2月, 2007 1 次提交
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由 Al Viro 提交于
* Split the implementation-agnostic stuff in separate files. * Make sure that targets using non-default request_irq() pull kernel/irq/devres.o * Introduce new symbols (HAS_IOPORT and HAS_IOMEM) defaulting to positive; allow architectures to turn them off (we needed these symbols anyway for dependencies of quite a few drivers). * protect the ioport-related parts of lib/devres.o with CONFIG_HAS_IOPORT. Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 10 2月, 2007 1 次提交
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由 Tejun Heo 提交于
Implement device resource management, in short, devres. A device driver can allocate arbirary size of devres data which is associated with a release function. On driver detach, release function is invoked on the devres data, then, devres data is freed. devreses are typed by associated release functions. Some devreses are better represented by single instance of the type while others need multiple instances sharing the same release function. Both usages are supported. devreses can be grouped using devres group such that a device driver can easily release acquired resources halfway through initialization or selectively release resources (e.g. resources for port 1 out of 4 ports). This patch adds devres core including documentation and the following managed interfaces. * alloc/free : devm_kzalloc(), devm_kzfree() * IO region : devm_request_region(), devm_release_region() * IRQ : devm_request_irq(), devm_free_irq() * DMA : dmam_alloc_coherent(), dmam_free_coherent(), dmam_declare_coherent_memory(), dmam_pool_create(), dmam_pool_destroy() * PCI : pcim_enable_device(), pcim_pin_device(), pci_is_managed() * iomap : devm_ioport_map(), devm_ioport_unmap(), devm_ioremap(), devm_ioremap_nocache(), devm_iounmap(), pcim_iomap_table(), pcim_iomap(), pcim_iounmap() Signed-off-by: NTejun Heo <htejun@gmail.com> Signed-off-by: NJeff Garzik <jeff@garzik.org>
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- 24 1月, 2007 1 次提交
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由 Linus Torvalds 提交于
Any newly added irq handler may obviously make any old spurious irq status invalid, since the new handler may well be the thing that is supposed to handle any interrupts that came in. So just clear the statistics when adding handlers. Pointed-out-by: NAlan Cox <alan@lxorguk.ukuu.org.uk> Acked-by: NThomas Gleixner <tglx@linutronix.de> Acked-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 15 11月, 2006 1 次提交
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由 Andrew Morton 提交于
When we get a mismatch between handlers on the same IRQ, all we get is "IRQ handler type mismatch for IRQ n". Let's print the name of the presently-registered handler with which we got the mismatch. Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 05 10月, 2006 1 次提交
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由 David Howells 提交于
Typedef the IRQ handler function type. Signed-Off-By: NDavid Howells <dhowells@redhat.com> (cherry picked from 1356d1e5fd256997e3d3dce0777ab787d0515c7a commit)
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- 01 8月, 2006 1 次提交
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由 David Brownell 提交于
IRQs need refcounting and a state flag to track whether the the IRQ should be enabled or disabled as a "normal IRQ" source after a series of calls to {en,dis}able_irq(). For shared IRQs, the IRQ must be enabled so long as at least one driver needs it active. Likewise, IRQs need the same support to track whether the IRQ should be enabled or disabled as a "wakeup event" source after a series of calls to {en,dis}able_irq_wake(). For shared IRQs, the IRQ must be enabled as a wakeup source during sleep so long as at least one driver needs it. But right now they _don't have_ that refcounting ... which means sharing a wakeup-capable IRQ can't work correctly in some configurations. This patch adds the refcount and flag mechanisms to set_irq_wake() -- which is what {en,dis}able_irq_wake() call -- and minimal documentation of what the irq wake mechanism does. Drivers relying on the older (broken) "toggle" semantics will trigger a warning; that'll be a handful of drivers on ARM systems. Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net> Acked-by: NIngo Molnar <mingo@elte.hu> Acked-by: NThomas Gleixner <tglx@linutronix.de> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 04 7月, 2006 1 次提交
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由 Ingo Molnar 提交于
Do 'make oldconfig' and accept all the defaults for new config options - reboot into the kernel and if everything goes well it should boot up fine and you should have /proc/lockdep and /proc/lockdep_stats files. Typically if the lock validator finds some problem it will print out voluminous debug output that begins with "BUG: ..." and which syslog output can be used by kernel developers to figure out the precise locking scenario. What does the lock validator do? It "observes" and maps all locking rules as they occur dynamically (as triggered by the kernel's natural use of spinlocks, rwlocks, mutexes and rwsems). Whenever the lock validator subsystem detects a new locking scenario, it validates this new rule against the existing set of rules. If this new rule is consistent with the existing set of rules then the new rule is added transparently and the kernel continues as normal. If the new rule could create a deadlock scenario then this condition is printed out. When determining validity of locking, all possible "deadlock scenarios" are considered: assuming arbitrary number of CPUs, arbitrary irq context and task context constellations, running arbitrary combinations of all the existing locking scenarios. In a typical system this means millions of separate scenarios. This is why we call it a "locking correctness" validator - for all rules that are observed the lock validator proves it with mathematical certainty that a deadlock could not occur (assuming that the lock validator implementation itself is correct and its internal data structures are not corrupted by some other kernel subsystem). [see more details and conditionals of this statement in include/linux/lockdep.h and Documentation/lockdep-design.txt] Furthermore, this "all possible scenarios" property of the validator also enables the finding of complex, highly unlikely multi-CPU multi-context races via single single-context rules, increasing the likelyhood of finding bugs drastically. In practical terms: the lock validator already found a bug in the upstream kernel that could only occur on systems with 3 or more CPUs, and which needed 3 very unlikely code sequences to occur at once on the 3 CPUs. That bug was found and reported on a single-CPU system (!). So in essence a race will be found "piecemail-wise", triggering all the necessary components for the race, without having to reproduce the race scenario itself! In its short existence the lock validator found and reported many bugs before they actually caused a real deadlock. To further increase the efficiency of the validator, the mapping is not per "lock instance", but per "lock-class". For example, all struct inode objects in the kernel have inode->inotify_mutex. If there are 10,000 inodes cached, then there are 10,000 lock objects. But ->inotify_mutex is a single "lock type", and all locking activities that occur against ->inotify_mutex are "unified" into this single lock-class. The advantage of the lock-class approach is that all historical ->inotify_mutex uses are mapped into a single (and as narrow as possible) set of locking rules - regardless of how many different tasks or inode structures it took to build this set of rules. The set of rules persist during the lifetime of the kernel. To see the rough magnitude of checking that the lock validator does, here's a portion of /proc/lockdep_stats, fresh after bootup: lock-classes: 694 [max: 2048] direct dependencies: 1598 [max: 8192] indirect dependencies: 17896 all direct dependencies: 16206 dependency chains: 1910 [max: 8192] in-hardirq chains: 17 in-softirq chains: 105 in-process chains: 1065 stack-trace entries: 38761 [max: 131072] combined max dependencies: 2033928 hardirq-safe locks: 24 hardirq-unsafe locks: 176 softirq-safe locks: 53 softirq-unsafe locks: 137 irq-safe locks: 59 irq-unsafe locks: 176 The lock validator has observed 1598 actual single-thread locking patterns, and has validated all possible 2033928 distinct locking scenarios. More details about the design of the lock validator can be found in Documentation/lockdep-design.txt, which can also found at: http://redhat.com/~mingo/lockdep-patches/lockdep-design.txt [bunk@stusta.de: cleanups] Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NArjan van de Ven <arjan@linux.intel.com> Signed-off-by: NAdrian Bunk <bunk@stusta.de> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 03 7月, 2006 2 次提交
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由 Thomas Gleixner 提交于
The irqflags consolidation converted SA_PERCPU_IRQ to IRQF_PERCPU but did not define the new constant. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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由 Thomas Gleixner 提交于
Signed-off-by: NThomas 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: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 02 7月, 2006 2 次提交
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由 Bjorn Helgaas 提交于
Make warnings more consistent. Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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由 Bjorn Helgaas 提交于
IRQ_PER_CPU is a bit in the struct irq_desc "status" field, not in the struct irqaction "flags", so the previous code checked the wrong bit. SA_PERCPU_IRQ is only used by drivers/char/mmtimer.c for SGI ia64 boxes. Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com> Acked-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 01 7月, 2006 1 次提交
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由 Jörn Engel 提交于
Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: NAdrian Bunk <bunk@stusta.de>
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- 30 6月, 2006 6 次提交
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由 Ingo Molnar 提交于
Rename no_irq_type to no_irq_chip. Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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由 Thomas Gleixner 提交于
Enable drivers to request an IRQ with a given irq-flow (trigger/polarity) setting. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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由 Thomas Gleixner 提交于
Enable platforms to set the irq-wake (power-management) properties of an IRQ. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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由 Thomas Gleixner 提交于
Core genirq support: add the irq-chip and irq-flow abstractions. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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由 Ingo Molnar 提交于
Update/add copyrights in the generic IRQ code. Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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由 Thomas Gleixner 提交于
Enable platforms to disable the automatic enabling of freshly set up irqs. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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