Messages in this thread Patch in this message | | | From | Balaji Rao <> | Subject | Re: hpet_late_init hang | Date | Wed, 16 Jan 2008 14:04:33 +0530 |
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On Wednesday 16 January 2008 12:21:33 pm Ingo Molnar wrote: Hi Ingo, > * Yinghai Lu <yhlu.kernel@gmail.com> wrote: > > " > > commit e5ed385fa0d6f35406e3e3ed75e5eb9adeb811df > > Author: Balaji Rao <balajirrao@gmail.com> > > Date: Tue Jan 15 16:53:29 2008 +0100 > > > > Assign IRQs to HPET Timers > > " > > in x86.git > > > > cause my servers hang > > after > > Calling initcall 0xffffffff80b9a465: hpet_late_init+0x0/0x100() > > i'm wondering, where does it hang exactly and why? > > > after reverting that I got: > > > > initcall 0xffffffff80b947d1 ran for 19 msecs: pci_iommu_init+0x0/0x13() > > Calling initcall 0xffffffff80b9a465: hpet_late_init+0x0/0x100() > > hpet0: at MMIO 0xfed00000, IRQs 2, 8, 31 > > hpet0: 3 32-bit timers, 25000000 Hz > > initcall 0xffffffff80b9a465: hpet_late_init+0x0/0x100() returned 0. > > initcall 0xffffffff80b9a465 ran for 7 msecs: hpet_late_init+0x0/0x100() > > Looks like IRQ 31 is assigned to timer 3, even without the patch! I wonder who wrote the number 31. But the manual says that it is zero by default.
I think we should check whether the timer has been allocated an IRQ before proceeding to assign one to it. Here is a patch that does this.
Yinghai, could you please apply this on top of my patch and check ?
--- Index: linux-2.6/arch/x86/kernel/hpet.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/hpet.c +++ linux-2.6/arch/x86/kernel/hpet.c @@ -116,7 +116,8 @@ int is_hpet_enabled(void) static void hpet_reserve_platform_timers(unsigned long id) { struct hpet __iomem *hpet = hpet_virt_address; - unsigned int nrtimers; + struct hpet_timer __iomem *timer = &hpet->hpet_timers[2]; + unsigned int nrtimers, i; struct hpet_data hd; nrtimers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1; @@ -134,10 +135,9 @@ static void hpet_reserve_platform_timers hd.hd_irq[0] = HPET_LEGACY_8254; hd.hd_irq[1] = HPET_LEGACY_RTC; - /* - * IRQs for the other timers are assigned dynamically - * in hpet_alloc - */ + for (i = 2; i < nrtimers; timer++, i++) + hd.hd_irq[i] = (timer->hpet_config & Tn_INT_ROUTE_CNF_MASK) >> + Tn_INT_ROUTE_CNF_SHIFT; hpet_alloc(&hd); } #else Index: linux-2.6/drivers/char/hpet.c =================================================================== --- linux-2.6.orig/drivers/char/hpet.c +++ linux-2.6/drivers/char/hpet.c @@ -852,6 +852,12 @@ int hpet_alloc(struct hpet_data *hdp) timer = &hpet->hpet_timers[devp - hpetp->hp_dev]; + /* Check if there's already an IRQ assigned to the timer */ + if (hdp->hd_irq[i]) { + hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i]; + continue; + } + hpet_config = readq(&timer->hpet_config); irq_bitmap = (hpet_config & Tn_INT_ROUTE_CAP_MASK) >> Tn_INT_ROUTE_CAP_SHIFT; --- regards, balaji rao
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