* Balaji Rao <[EMAIL PROTECTED]> [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 <[EMAIL PROTECTED]>
>
> 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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