On Fri, 2017-12-29 at 14:10 +0100, Thomas Gleixner wrote:
> On Fri, 29 Dec 2017, Andy Shevchenko wrote:
> 
> > On Thu, 2017-12-28 at 22:59 +0100, Thomas Gleixner wrote:
> > > On Thu, 28 Dec 2017, Thomas Gleixner wrote:
> > > > On Thu, 28 Dec 2017, Andy Shevchenko wrote:
> > > > > The result w/o above is (full log is available here
> > > > > https://pastebin.com
> > > > > /J5yaTbM9):
> > > > 
> > > > Ok. Which irqs are related to that ISP thingy?
> > > > 
> > > > Are these interrupts MSI?
> > 
> > Yes, they are MSI.
> > 
> > > And looking at the log, I see that you can load the driver
> > > successfully and
> > > the trouble starts afterwards when you actually use it.
> > 
> > Correct.
> > 
> > > Can you please enable CONFIG_GENERIC_IRQ_DEBUGFS and after login,
> > > check
> > > which interrupt is assigned to that atomisp thingy and then
> > > provide
> > > the
> > > output of
> > > 
> > > cat /sys/kernel/debug/irq/irqs/$ATOMISPIRQ
> > 
> > Full log, including output of the above.
> > 
> > https://pastebin.com/4jammqi5
> 
> Thanks for the info. Can you please test the patch below?

Thanks for the patch. It does a trick!

P.S. I noticed that it's combined from at least one that is already in
x86/urgent, so, feel free to add my

Reported-by: Andy Shevchenko <andriy.shevche...@linux.intel.com>
Tested-by: Andy Shevchenko <andriy.shevche...@linux.intel.com>

to the rest

> 
> Thanks,
> 
>       tglx
> 
> 8<--------------------
> --- a/kernel/irq/msi.c
> +++ b/kernel/irq/msi.c
> @@ -339,6 +339,40 @@ int msi_domain_populate_irqs(struct irq_
>       return ret;
>  }
>  
> +/*
> + * Carefully check whether the device can use reservation mode. If
> + * reservation mode is enabled then the early activation will assign
> a
> + * dummy vector to the device. If the PCI/MSI device does not support
> + * masking of the entry then this can result in spurious interrupts
> when
> + * the device driver is not absolutely careful. But even then a
> malfunction
> + * of the hardware could result in a spurious interrupt on the dummy
> vector
> + * and render the device unusable. If the entry can be masked then
> the core
> + * logic will prevent the spurious interrupt and reservation mode can
> be
> + * used. For now reservation mode is restricted to PCI/MSI.
> + */
> +static bool msi_check_reservation_mode(struct irq_domain *domain,
> +                                    struct msi_domain_info *info,
> +                                    struct device *dev)
> +{
> +     struct msi_desc *desc;
> +
> +     if (domain->bus_token != DOMAIN_BUS_PCI_MSI)
> +             return false;
> +
> +     if (!(info->flags & MSI_FLAG_MUST_REACTIVATE))
> +             return false;
> +
> +     if (IS_ENABLED(CONFIG_PCI_MSI) && pci_msi_ignore_mask)
> +             return false;
> +
> +     /*
> +      * Checking the first MSI descriptor is sufficient. MSIX
> supports
> +      * masking and MSI does so when the maskbit is set.
> +      */
> +     desc = first_msi_entry(dev);
> +     return desc->msi_attrib.is_msix || desc->msi_attrib.maskbit;
> +}
> +
>  /**
>   * msi_domain_alloc_irqs - Allocate interrupts from a MSI interrupt
> domain
>   * @domain:  The domain to allocate from
> @@ -353,9 +387,11 @@ int msi_domain_alloc_irqs(struct irq_dom
>  {
>       struct msi_domain_info *info = domain->host_data;
>       struct msi_domain_ops *ops = info->ops;
> -     msi_alloc_info_t arg;
> +     struct irq_data *irq_data;
>       struct msi_desc *desc;
> +     msi_alloc_info_t arg;
>       int i, ret, virq;
> +     bool can_reserve;
>  
>       ret = msi_domain_prepare_irqs(domain, dev, nvec, &arg);
>       if (ret)
> @@ -385,6 +421,8 @@ int msi_domain_alloc_irqs(struct irq_dom
>       if (ops->msi_finish)
>               ops->msi_finish(&arg, 0);
>  
> +     can_reserve = msi_check_reservation_mode(domain, info, dev);
> +
>       for_each_msi_entry(desc, dev) {
>               virq = desc->irq;
>               if (desc->nvec_used == 1)
> @@ -397,17 +435,28 @@ int msi_domain_alloc_irqs(struct irq_dom
>                * the MSI entries before the PCI layer enables MSI
> in the
>                * card. Otherwise the card latches a random msi
> message.
>                */
> -             if (info->flags & MSI_FLAG_ACTIVATE_EARLY) {
> -                     struct irq_data *irq_data;
> +             if (!(info->flags & MSI_FLAG_ACTIVATE_EARLY))
> +                     continue;
>  
> +             irq_data = irq_domain_get_irq_data(domain, desc-
> >irq);
> +             if (!can_reserve)
> +                     irqd_clr_can_reserve(irq_data);
> +             ret = irq_domain_activate_irq(irq_data, can_reserve);
> +             if (ret)
> +                     goto cleanup;
> +     }
> +
> +     /*
> +      * If these interrupts use reservation mode clear the
> activated bit
> +      * so request_irq() will assign the final vector.
> +      */
> +     if (can_reserve) {
> +             for_each_msi_entry(desc, dev) {
>                       irq_data = irq_domain_get_irq_data(domain,
> desc->irq);
> -                     ret = irq_domain_activate_irq(irq_data,
> true);
> -                     if (ret)
> -                             goto cleanup;
> -                     if (info->flags & MSI_FLAG_MUST_REACTIVATE)
> -                             irqd_clr_activated(irq_data);
> +                     irqd_clr_activated(irq_data);
>               }
>       }
> +
>       return 0;
>  
>  cleanup:
> --- a/arch/x86/kernel/apic/vector.c
> +++ b/arch/x86/kernel/apic/vector.c
> @@ -184,6 +184,7 @@ static void reserve_irq_vector_locked(st
>       irq_matrix_reserve(vector_matrix);
>       apicd->can_reserve = true;
>       apicd->has_reserved = true;
> +     irqd_set_can_reserve(irqd);
>       trace_vector_reserve(irqd->irq, 0);
>       vector_assign_managed_shutdown(irqd);
>  }
> @@ -368,8 +369,18 @@ static int activate_reserved(struct irq_
>       int ret;
>  
>       ret = assign_irq_vector_any_locked(irqd);
> -     if (!ret)
> +     if (!ret) {
>               apicd->has_reserved = false;
> +             /*
> +              * Core might have disabled reservation mode after
> +              * allocating the irq descriptor. Ideally this should
> +              * happen before allocation time, but that would
> require
> +              * completely convoluted ways of transporting that
> +              * information.
> +              */
> +             if (!irqd_can_reserve(irqd))
> +                     apicd->can_reserve = false;
> +     }
>       return ret;
>  }
>  
> @@ -478,6 +489,7 @@ static bool vector_configure_legacy(unsi
>       } else {
>               /* Release the vector */
>               apicd->can_reserve = true;
> +             irqd_set_can_reserve(irqd);
>               clear_irq_vector(irqd);
>               realloc = true;
>       }
> --- a/include/linux/irq.h
> +++ b/include/linux/irq.h
> @@ -212,6 +212,7 @@ struct irq_data {
>   *                             mask. Applies only to affinity
> managed irqs.
>   * IRQD_SINGLE_TARGET                - IRQ allows only a single
> affinity target
>   * IRQD_DEFAULT_TRIGGER_SET  - Expected trigger already been
> set
> + * IRQD_CAN_RESERVE          - Can use reservation mode
>   */
>  enum {
>       IRQD_TRIGGER_MASK               = 0xf,
> @@ -233,6 +234,7 @@ enum {
>       IRQD_MANAGED_SHUTDOWN           = (1 << 23),
>       IRQD_SINGLE_TARGET              = (1 << 24),
>       IRQD_DEFAULT_TRIGGER_SET        = (1 << 25),
> +     IRQD_CAN_RESERVE                = (1 << 26),
>  };
>  
>  #define __irqd_to_state(d) ACCESS_PRIVATE((d)->common,
> state_use_accessors)
> @@ -377,6 +379,21 @@ static inline bool irqd_is_managed_and_s
>       return __irqd_to_state(d) & IRQD_MANAGED_SHUTDOWN;
>  }
>  
> +static inline void irqd_set_can_reserve(struct irq_data *d)
> +{
> +     __irqd_to_state(d) |= IRQD_CAN_RESERVE;
> +}
> +
> +static inline void irqd_clr_can_reserve(struct irq_data *d)
> +{
> +     __irqd_to_state(d) &= ~IRQD_CAN_RESERVE;
> +}
> +
> +static inline bool irqd_can_reserve(struct irq_data *d)
> +{
> +     return __irqd_to_state(d) & IRQD_CAN_RESERVE;
> +}
> +
>  #undef __irqd_to_state
>  
>  static inline irq_hw_number_t irqd_to_hwirq(struct irq_data *d)
> --- a/kernel/irq/debugfs.c
> +++ b/kernel/irq/debugfs.c
> @@ -113,6 +113,7 @@ static const struct irq_bit_descr irqdat
>       BIT_MASK_DESCR(IRQD_SETAFFINITY_PENDING),
>       BIT_MASK_DESCR(IRQD_AFFINITY_MANAGED),
>       BIT_MASK_DESCR(IRQD_MANAGED_SHUTDOWN),
> +     BIT_MASK_DESCR(IRQD_CAN_RESERVE),
>  
>       BIT_MASK_DESCR(IRQD_FORWARDED_TO_VCPU),
>  
> --- a/arch/x86/kernel/apic/apic_flat_64.c
> +++ b/arch/x86/kernel/apic/apic_flat_64.c
> @@ -151,7 +151,7 @@ static struct apic apic_flat __ro_after_
>       .apic_id_valid                  =
> default_apic_id_valid,
>       .apic_id_registered             = flat_apic_id_registered,
>  
> -     .irq_delivery_mode              = dest_LowestPrio,
> +     .irq_delivery_mode              = dest_Fixed,
>       .irq_dest_mode                  = 1, /* logical */
>  
>       .disable_esr                    = 0,
> --- a/arch/x86/kernel/apic/apic_noop.c
> +++ b/arch/x86/kernel/apic/apic_noop.c
> @@ -110,7 +110,7 @@ struct apic apic_noop __ro_after_init =
>       .apic_id_valid                  =
> default_apic_id_valid,
>       .apic_id_registered             = noop_apic_id_registered,
>  
> -     .irq_delivery_mode              = dest_LowestPrio,
> +     .irq_delivery_mode              = dest_Fixed,
>       /* logical delivery broadcast to all CPUs: */
>       .irq_dest_mode                  = 1,
>  
> --- a/arch/x86/kernel/apic/msi.c
> +++ b/arch/x86/kernel/apic/msi.c
> @@ -39,17 +39,13 @@ static void irq_msi_compose_msg(struct i
>               ((apic->irq_dest_mode == 0) ?
>                       MSI_ADDR_DEST_MODE_PHYSICAL :
>                       MSI_ADDR_DEST_MODE_LOGICAL) |
> -             ((apic->irq_delivery_mode != dest_LowestPrio) ?
> -                     MSI_ADDR_REDIRECTION_CPU :
> -                     MSI_ADDR_REDIRECTION_LOWPRI) |
> +             MSI_ADDR_REDIRECTION_CPU |
>               MSI_ADDR_DEST_ID(cfg->dest_apicid);
>  
>       msg->data =
>               MSI_DATA_TRIGGER_EDGE |
>               MSI_DATA_LEVEL_ASSERT |
> -             ((apic->irq_delivery_mode != dest_LowestPrio) ?
> -                     MSI_DATA_DELIVERY_FIXED :
> -                     MSI_DATA_DELIVERY_LOWPRI) |
> +             MSI_DATA_DELIVERY_FIXED |
>               MSI_DATA_VECTOR(cfg->vector);
>  }
>  
> --- a/arch/x86/kernel/apic/probe_32.c
> +++ b/arch/x86/kernel/apic/probe_32.c
> @@ -105,7 +105,7 @@ static struct apic apic_default __ro_aft
>       .apic_id_valid                  =
> default_apic_id_valid,
>       .apic_id_registered             =
> default_apic_id_registered,
>  
> -     .irq_delivery_mode              = dest_LowestPrio,
> +     .irq_delivery_mode              = dest_Fixed,
>       /* logical delivery broadcast to all CPUs: */
>       .irq_dest_mode                  = 1,
>  
> --- a/arch/x86/kernel/apic/x2apic_cluster.c
> +++ b/arch/x86/kernel/apic/x2apic_cluster.c
> @@ -184,7 +184,7 @@ static struct apic apic_x2apic_cluster _
>       .apic_id_valid                  = x2apic_apic_id_valid,
>       .apic_id_registered             =
> x2apic_apic_id_registered,
>  
> -     .irq_delivery_mode              = dest_LowestPrio,
> +     .irq_delivery_mode              = dest_Fixed,
>       .irq_dest_mode                  = 1, /* logical */
>  
>       .disable_esr                    = 0,
> --- a/drivers/pci/host/pci-hyperv.c
> +++ b/drivers/pci/host/pci-hyperv.c
> @@ -985,9 +985,7 @@ static u32 hv_compose_msi_req_v1(
>       int_pkt->wslot.slot = slot;
>       int_pkt->int_desc.vector = vector;
>       int_pkt->int_desc.vector_count = 1;
> -     int_pkt->int_desc.delivery_mode =
> -             (apic->irq_delivery_mode == dest_LowestPrio) ?
> -                     dest_LowestPrio : dest_Fixed;
> +     int_pkt->int_desc.delivery_mode = dest_Fixed;
>  
>       /*
>        * Create MSI w/ dummy vCPU set, overwritten by subsequent
> retarget in
> @@ -1008,9 +1006,7 @@ static u32 hv_compose_msi_req_v2(
>       int_pkt->wslot.slot = slot;
>       int_pkt->int_desc.vector = vector;
>       int_pkt->int_desc.vector_count = 1;
> -     int_pkt->int_desc.delivery_mode =
> -             (apic->irq_delivery_mode == dest_LowestPrio) ?
> -                     dest_LowestPrio : dest_Fixed;
> +     int_pkt->int_desc.delivery_mode = dest_Fixed;
>  
>       /*
>        * Create MSI w/ dummy vCPU set targeting just one vCPU,
> overwritten

-- 
Andy Shevchenko <andriy.shevche...@linux.intel.com>
Intel Finland Oy

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