Commit cb17b2a6 authored Jun 21, 2015 by Thomas Gleixner

x86/hpet: Use proper hpet device number for MSI allocation



hpet_assign_irq() is called with hpet_device->num as "hardware
interrupt number", but hpet_device->num is initialized after the
interrupt has been assigned, so it's always 0. As a consequence only
the first MSI allocation succeeds, the following ones fail because the
"hardware interrupt number" already exists.

Move the initialization of dev->num and other fields before the call
to hpet_assign_irq(), which is the ordering before the offending
commit which introduced that regression.

Fixes: "3cb96f0c x86/hpet: Enhance HPET IRQ to support hierarchical irqdomains"
Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1506211635010.4107@nanos
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>

parent bafac298

arch/x86/kernel/hpet.c

+6 −5

Original line number	Diff line number	Diff line
		@@ -577,16 +577,17 @@ static void hpet_msi_capability_lookup(unsigned int start_timer)
		if (!(cfg & HPET_TN_FSB_CAP))
		continue;

		hdev->flags = 0;
		if (cfg & HPET_TN_PERIODIC_CAP)
		hdev->flags \|= HPET_DEV_PERI_CAP;
		sprintf(hdev->name, "hpet%d", i);
		hdev->num = i;

		irq = hpet_assign_irq(hpet_domain, hdev, hdev->num);
		if (irq <= 0)
		continue;

		sprintf(hdev->name, "hpet%d", i);
		hdev->num = i;
		hdev->irq = irq;
		hdev->flags = 0;
		if (cfg & HPET_TN_PERIODIC_CAP)
		hdev->flags \|= HPET_DEV_PERI_CAP;
		hdev->flags \|= HPET_DEV_FSB_CAP;
		hdev->flags \|= HPET_DEV_VALID;
		num_timers_used++;

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