Re: [PATCH REPOST #2] IB/ehca: In case of lost interrupts, trigger EOI to reenable interrupts

From: Roland Dreier
Date: Thu Jun 19 2008 - 18:35:54 EST


> During corner case testing, we noticed that some versions of ehca
> do not properly transition to interrupt done in special load situations.
> This can be resolved by periodically triggering EOI through H_EOI,
> if eqes are pending.
>
> Signed-off-by: Stefan Roscher <stefan.roscher@xxxxxxxxxx>
> ---
> As firmware team suggested I moved the call of the EOI h_call into
> the handler function, this ensures that we will call EOI only when we
> find a valid eqe on the event queue.
> Additionally I changed the calculation of the xirr value as Roland suggested.

paulus / benh -- does this version still get your ack? Seems that fw
team is OK with it according to Stefan...

If so I will add this to my tree for 2.6.27.

> diff --git a/drivers/infiniband/hw/ehca/ehca_irq.c b/drivers/infiniband/hw/ehca/ehca_irq.c
> index ce1ab05..0792d93 100644
> --- a/drivers/infiniband/hw/ehca/ehca_irq.c
> +++ b/drivers/infiniband/hw/ehca/ehca_irq.c
> @@ -531,7 +531,7 @@ void ehca_process_eq(struct ehca_shca *shca, int is_irq)
> {
> struct ehca_eq *eq = &shca->eq;
> struct ehca_eqe_cache_entry *eqe_cache = eq->eqe_cache;
> - u64 eqe_value;
> + u64 eqe_value, ret;
> unsigned long flags;
> int eqe_cnt, i;
> int eq_empty = 0;
> @@ -583,8 +583,13 @@ void ehca_process_eq(struct ehca_shca *shca, int is_irq)
> ehca_dbg(&shca->ib_device,
> "No eqe found for irq event");
> goto unlock_irq_spinlock;
> - } else if (!is_irq)
> + } else if (!is_irq) {
> + ret = hipz_h_eoi(eq->ist);
> + if (ret != H_SUCCESS)
> + ehca_err(&shca->ib_device,
> + "bad return code EOI -rc = %ld\n", ret);
> ehca_dbg(&shca->ib_device, "deadman found %x eqe", eqe_cnt);
> + }
> if (unlikely(eqe_cnt == EHCA_EQE_CACHE_SIZE))
> ehca_dbg(&shca->ib_device, "too many eqes for one irq event");
> /* enable irq for new packets */
> diff --git a/drivers/infiniband/hw/ehca/hcp_if.c b/drivers/infiniband/hw/ehca/hcp_if.c
> index 5245e13..415d3a4 100644
> --- a/drivers/infiniband/hw/ehca/hcp_if.c
> +++ b/drivers/infiniband/hw/ehca/hcp_if.c
> @@ -933,3 +933,13 @@ u64 hipz_h_error_data(const struct ipz_adapter_handle adapter_handle,
> r_cb,
> 0, 0, 0, 0);
> }
> +
> +u64 hipz_h_eoi(int irq)
> +{
> + unsigned long xirr;
> +
> + iosync();
> + xirr = (0xffULL << 24) | irq;
> +
> + return plpar_hcall_norets(H_EOI, xirr);
> +}
> diff --git a/drivers/infiniband/hw/ehca/hcp_if.h b/drivers/infiniband/hw/ehca/hcp_if.h
> index 60ce02b..2c3c6e0 100644
> --- a/drivers/infiniband/hw/ehca/hcp_if.h
> +++ b/drivers/infiniband/hw/ehca/hcp_if.h
> @@ -260,5 +260,6 @@ u64 hipz_h_error_data(const struct ipz_adapter_handle adapter_handle,
> const u64 ressource_handle,
> void *rblock,
> unsigned long *byte_count);
> +u64 hipz_h_eoi(int irq);
>
> #endif /* __HCP_IF_H__ */
> --
> 1.5.5
>
>
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