Messages in this thread Patch in this message | | | From | Sven Joachim <> | Subject | Re: [ 57/72] genirq: Unmask oneshot irqs when thread was not woken | Date | Sun, 04 Mar 2012 22:06:32 +0100 |
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On 2012-02-28 02:05 +0100, Greg KH wrote:
> 3.2-stable review patch. If anyone has any objections, please let me know.
Alas, the commit below broke the WiFi on my laptop, where "iwlist wlan0 scan" now just reports: " wlan0 No scan results".
This is not specific to 3.2, the same problem exists in 3.0.23 and 3.3-rc6 while previous releases worked.
The laptop is an Acer TravelMate 2490 with a Broadcom chip:
,---- | 06:02.0 Network controller: Broadcom Corporation BCM4318 [AirForce One 54g] 802.11g Wireless LAN Controller (rev 02) | Subsystem: AMBIT Microsystem Corp. TravelMate 2410 | Flags: bus master, fast devsel, latency 64, IRQ 10 | Memory at d0002000 (32-bit, non-prefetchable) [size=8K] | Kernel driver in use: b43-pci-bridge `----
I'll be happy to give more information when needed.
Cheers, Sven
> From: Thomas Gleixner <tglx@linutronix.de> > > commit ac5637611150281f398bb7a47e3fcb69a09e7803 upstream. > > When the primary handler of an interrupt which is marked IRQ_ONESHOT > returns IRQ_HANDLED or IRQ_NONE, then the interrupt thread is not > woken and the unmask logic of the interrupt line is never > invoked. This keeps the interrupt masked forever. > > This was not noticed as most IRQ_ONESHOT users wake the thread > unconditionally (usually because they cannot access the underlying > device from hard interrupt context). Though this behaviour was nowhere > documented and not necessarily intentional. Some drivers can avoid the > thread wakeup in certain cases and run into the situation where the > interrupt line s kept masked. > > Handle it gracefully. > > Reported-and-tested-by: Lothar Wassmann <lw@karo-electronics.de> > Signed-off-by: Thomas Gleixner <tglx@linutronix.de> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > > --- > kernel/irq/chip.c | 25 +++++++++++++++++++++++-- > 1 file changed, 23 insertions(+), 2 deletions(-) > > --- a/kernel/irq/chip.c > +++ b/kernel/irq/chip.c > @@ -330,6 +330,24 @@ out_unlock: > } > EXPORT_SYMBOL_GPL(handle_simple_irq); > > +/* > + * Called unconditionally from handle_level_irq() and only for oneshot > + * interrupts from handle_fasteoi_irq() > + */ > +static void cond_unmask_irq(struct irq_desc *desc) > +{ > + /* > + * We need to unmask in the following cases: > + * - Standard level irq (IRQF_ONESHOT is not set) > + * - Oneshot irq which did not wake the thread (caused by a > + * spurious interrupt or a primary handler handling it > + * completely). > + */ > + if (!irqd_irq_disabled(&desc->irq_data) && > + irqd_irq_masked(&desc->irq_data) && !desc->threads_oneshot) > + unmask_irq(desc); > +} > + > /** > * handle_level_irq - Level type irq handler > * @irq: the interrupt number > @@ -362,8 +380,8 @@ handle_level_irq(unsigned int irq, struc > > handle_irq_event(desc); > > - if (!irqd_irq_disabled(&desc->irq_data) && !(desc->istate & IRQS_ONESHOT)) > - unmask_irq(desc); > + cond_unmask_irq(desc); > + > out_unlock: > raw_spin_unlock(&desc->lock); > } > @@ -417,6 +435,9 @@ handle_fasteoi_irq(unsigned int irq, str > preflow_handler(desc); > handle_irq_event(desc); > > + if (desc->istate & IRQS_ONESHOT) > + cond_unmask_irq(desc); > + > out_eoi: > desc->irq_data.chip->irq_eoi(&desc->irq_data); > out_unlock:
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