> On 02 November 2026 at 04:39 am, Ritesh Harjani <[email protected]> wrote:
>
> [email protected] writes:
>
>> From: Christian Zigotzky A-EON Open Source <[email protected]>
>>
>> Since pas_pci_init() is now called later during boot, the i8259
>> initialization in pas_init_IRQ() happens too early and accesses
>> registers that are not yet mapped, preventing the board from booting.
>>
>> Move the Nemo-specific i8259 initialization to pas_add_bridge(),
>> after the ISA bridge has been discovered.
>
>
> That make sense to me. The patch looks good. However, shouldn't we also
> add Fixes tag and Cc: stable tag - so that this gets backported to older
> stable kernels.
>
>
> Fixes: c144bc719234 ("powerpc/pasemi: Move PHB discovery")
> Cc: [email protected]
>
> I think the fixes tag should be above - but feel free to correct that.
>
> Otherwise looks good to me. Feel free to add:
> Reviewed-by: Ritesh Harjani (IBM) <[email protected]>
>
>
>>
>> Suggested-by: Darren Stevens <[email protected]>
>> Tested-by: Christian Zigotzky <[email protected]>
>> Signed-off-by: Christian Zigotzky A-EON Open Source <[email protected]>
>> ---
>> arch/powerpc/platforms/pasemi/pasemi.h | 6 ++++++
>> arch/powerpc/platforms/pasemi/pci.c | 5 +++++
>> arch/powerpc/platforms/pasemi/setup.c | 12 ++++--------
>> 3 files changed, 15 insertions(+), 8 deletions(-)
>>
>> diff --git a/arch/powerpc/platforms/pasemi/pasemi.h
>> b/arch/powerpc/platforms/pasemi/pasemi.h
>> index 6f6743b8e48d..01bcfa258625 100644
>> --- a/arch/powerpc/platforms/pasemi/pasemi.h
>> +++ b/arch/powerpc/platforms/pasemi/pasemi.h
>> @@ -7,6 +7,12 @@ extern void pas_pci_init(void);
>> struct pci_dev;
>> extern void pas_pci_dma_dev_setup(struct pci_dev *dev);
>>
>> +#ifdef CONFIG_PPC_PASEMI_NEMO
>> +void __init nemo_init_IRQ(void);
>> +#else
>> +static inline void __init nemo_init_IRQ(void) { }
>> +#endif
>> +
>> void __iomem *__init pasemi_pci_getcfgaddr(struct pci_dev *dev, int offset);
>>
>> extern void __init pasemi_map_registers(void);
>> diff --git a/arch/powerpc/platforms/pasemi/pci.c
>> b/arch/powerpc/platforms/pasemi/pci.c
>> index 2df955274652..fb53782da7ec 100644
>> --- a/arch/powerpc/platforms/pasemi/pci.c
>> +++ b/arch/powerpc/platforms/pasemi/pci.c
>> @@ -265,6 +265,11 @@ static int __init pas_add_bridge(struct device_node
>> *dev)
>> */
>> isa_bridge_find_early(hose);
>>
>> + /*
>> + * ISA bridge is now active, add the i8259 cascade (if needed)
>> + */
>> + nemo_init_IRQ();
>> +
>> return 0;
>> }
>>
>> diff --git a/arch/powerpc/platforms/pasemi/setup.c
>> b/arch/powerpc/platforms/pasemi/setup.c
>> index 45792ecd5dfd..7a961f2a228f 100644
>> --- a/arch/powerpc/platforms/pasemi/setup.c
>> +++ b/arch/powerpc/platforms/pasemi/setup.c
>> @@ -216,10 +216,12 @@ static void sb600_8259_cascade(struct irq_desc *desc)
>> chip->irq_eoi(&desc->irq_data);
>> }
>>
>> -static void __init nemo_init_IRQ(struct mpic *mpic)
>> +void __init nemo_init_IRQ(void)
>> {
>> struct device_node *np;
>> int gpio_virq;
>> + struct mpic *mpic;
>> +
>> /* Connect the SB600's legacy i8259 controller */
>> np = of_find_node_by_path("/pxp@0,e0000000");
>> i8259_init(np, 0);
>> @@ -230,14 +232,10 @@ static void __init nemo_init_IRQ(struct mpic *mpic)
>> irq_set_chained_handler(gpio_virq, sb600_8259_cascade);
>> mpic_unmask_irq(irq_get_irq_data(gpio_virq));
>>
>> + mpic = irq_get_chip_data(gpio_virq);
>> irq_set_default_domain(mpic->irqhost);
>> }
>>
>> -#else
>> -
>> -static inline void nemo_init_IRQ(struct mpic *mpic)
>> -{
>> -}
>> #endif
>>
>> static __init void pas_init_IRQ(void)
>> @@ -300,8 +298,6 @@ static __init void pas_init_IRQ(void)
>> mpic_unmask_irq(irq_get_irq_data(nmi_virq));
>> }
>>
>> - nemo_init_IRQ(mpic);
>> -
>> of_node_put(mpic_node);
>> of_node_put(root);
>> }
>> --
>> 2.43.0
Hi Michael,
I would like to ask about the status of my patch.
The patch received a positive review from Ritesh Harjani.
This fix is important for our Nemo boards, otherwise fails to boot with recent
kernels.
Thanks,
Christian
