Messages in this thread | | | From | (Eric W. Biederman) | Date | Wed, 30 Apr 2008 14:19:05 -0700 | Subject | Re: [PATCH] let setup_irq reenable a shared irq |
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Thomas Gleixner <tglx@linutronix.de> writes: > > Subject: genirq: reenable a nobody cared disabled irq when a new driver arrives > From: Thomas Gleixner <tglx@linutronix.de> > Date: Mon, 28 Apr 2008 17:01:56 +0200 > > 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 results 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) and this spurious irq issue is > raised on a regular base in bugreports.
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.
> Index: linux-2.6/include/linux/irq.h > =================================================================== > --- linux-2.6.orig/include/linux/irq.h > +++ linux-2.6/include/linux/irq.h > @@ -61,6 +61,7 @@ typedef void (*irq_flow_handler_t)(unsig > #define IRQ_WAKEUP 0x00100000 /* IRQ triggers system wakeup */ > #define IRQ_MOVE_PENDING 0x00200000 /* need to re-target IRQ destination */ > #define IRQ_NO_BALANCING 0x00400000 /* IRQ is excluded from balancing */ > +#define IRQ_SPURIOUS_DISABLED 0x00400000 /* IRQ was disabled by the spurious trap */
Looks like a duplicate define here. Don't you want: +#define IRQ_SPURIOUS_DISABLED 0x00800000 /* IRQ was disabled by the spurious trap */
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