Messages in this thread | | | Date | Sat, 12 Jan 2008 17:33:12 +0530 | From | Balbir Singh <> | Subject | Re: [PATCH] Assign IRQs to HPET Timers |
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* Balaji Rao <balajirrao@gmail.com> [2008-01-12 00:36:11]:
> Assign an IRQ to HPET Timer devices when interrupt enable is requested. > This now makes the HPET userspace API work. >
A more detailed changelog will better help understand the nature and origin of the problem and how to reproduce it.
> drivers/char/hpet.c | 31 +++++++++++++++++++++++++++++-- > include/linux/hpet.h | 2 +- > 2 files changed, 30 insertions(+), 3 deletions(-) > > Signed-off-by: Balaji Rao R <balajirrao@gmail.com> > > diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c > index 4c16778..92bd889 100644 > --- a/drivers/char/hpet.c > +++ b/drivers/char/hpet.c > @@ -390,7 +390,8 @@ static int hpet_ioctl_ieon(struct hpet_dev *devp) > struct hpets *hpetp; > int irq; > unsigned long g, v, t, m; > - unsigned long flags, isr; > + unsigned long flags, isr, irq_bitmap; > + u64 hpet_config; > > timer = devp->hd_timer; > hpet = devp->hd_hpet; > @@ -412,7 +413,29 @@ static int hpet_ioctl_ieon(struct hpet_dev *devp) > devp->hd_flags |= HPET_SHARED_IRQ; > spin_unlock_irq(&hpet_lock); > > - irq = devp->hd_hdwirq; > + /* Assign an IRQ to the timer */ > + hpet_config = readq(&timer->hpet_config); > + irq_bitmap = > + (hpet_config & Tn_INT_ROUTE_CAP_MASK) >> Tn_INT_ROUTE_CAP_SHIFT;
Should we check if the interrupts are being delivered via FSB, prior to doing this?
> + if (!irq_bitmap) > + irq = 0; /* No IRQ Assignable */ > + else { > + irq = find_first_bit(&irq_bitmap, 32);
> + do { > + hpet_config |= irq << Tn_INT_ROUTE_CNF_SHIFT; > + writeq(hpet_config, &timer->hpet_config); > + > + /* Check whether we wrote a valid IRQ > + * number by reading back the field > + */ > + hpet_config = readq(&timer->hpet_config); > + if (irq == (hpet_config & Tn_INT_ROUTE_CNF_MASK) > + >> Tn_INT_ROUTE_CNF_SHIFT) { > + devp->hd_hdwirq = irq; > + break; /* Success */ > + } > + } while ((irq = (find_next_bit(&irq_bitmap, 32, irq)))); > + }
Shouldn't we do this at hpet_alloc() time?
> > if (irq) { > unsigned long irq_flags; > @@ -509,6 +532,10 @@ hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel) > break; > v = readq(&timer->hpet_config); > v &= ~Tn_INT_ENB_CNF_MASK; > + > + /* Zero out the IRQ field*/ > + v &= ~Tn_INT_ROUTE_CNF_MASK; > + > writeq(v, &timer->hpet_config); > if (devp->hd_irq) { > free_irq(devp->hd_irq, devp); > diff --git a/include/linux/hpet.h b/include/linux/hpet.h > index 707f7cb..e3c0b2a 100644 > --- a/include/linux/hpet.h > +++ b/include/linux/hpet.h > @@ -64,7 +64,7 @@ struct hpet { > */ > > #define Tn_INT_ROUTE_CAP_MASK (0xffffffff00000000ULL) > -#define Tn_INI_ROUTE_CAP_SHIFT (32UL) > +#define Tn_INT_ROUTE_CAP_SHIFT (32UL) > #define Tn_FSB_INT_DELCAP_MASK (0x8000UL) > #define Tn_FSB_INT_DELCAP_SHIFT (15) > #define Tn_FSB_EN_CNF_MASK (0x4000UL)
The patch looks good overall!
-- Warm Regards, Balbir Singh Linux Technology Center IBM, ISTL
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