Re: [PATCH] genirq: Add the entropy pool function to the PPI interrupt handler

["enlin.mu" <enlin.mu@linux.dev>]

On 2026/6/16 15:24, Greg KH wrote:
> On Tue, Jun 16, 2026 at 03:17:00PM +0800, enlin.mu wrote:
>>
>>
>> On 2026/6/16 14:48, Greg KH wrote:
>>> A: http://en.wikipedia.org/wiki/Top_post
>>> Q: Were do I find info about this thing called top-posting?
>>> A: Because it messes up the order in which people normally read text.
>>> Q: Why is top-posting such a bad thing?
>>> A: Top-posting.
>>> Q: What is the most annoying thing in e-mail?
>>>
>>> A: No.
>>> Q: Should I include quotations after my reply?
>>>
>>> http://daringfireball.net/2007/07/on_top
>>>
>>> On Tue, Jun 16, 2026 at 02:26:18PM +0800, enlin.mu wrote:
>>>> Hi KH
>>>>
>>>> hardware: raspberrypi 5
>>>>
>>>> other patch(These two locations impact the entropy pool acceleration.
>>>> comment them out temporarily):
>>>> acer@raspberrypi:linux $ git diff drivers/of/fdt.c
>>>> drivers/char/hw_random/iproc-rng200.c
>>>> diff --git a/drivers/char/hw_random/iproc-rng200.c
>>>> b/drivers/char/hw_random/iproc-rng200.c
>>>> index 33bc28f429f6..af105faa88c6 100644
>>>> --- a/drivers/char/hw_random/iproc-rng200.c
>>>> +++ b/drivers/char/hw_random/iproc-rng200.c
>>>> @@ -296,10 +296,10 @@ static const struct dev_pm_ops iproc_rng200_pm_ops = {
>>>>    };
>>>>
>>>>    static const struct of_device_id iproc_rng200_of_match[] = {
>>>> -       { .compatible = "brcm,bcm2711-rng200", },
>>>> -       { .compatible = "brcm,bcm7211-rng200", },
>>>> -       { .compatible = "brcm,bcm7278-rng200", },
>>>> -       { .compatible = "brcm,iproc-rng200", },
>>>> +       { .compatible = "brcm,bcm2711-rng2000", },
>>>> +       { .compatible = "brcm,bcm7211-rng2000", },
>>>> +       { .compatible = "brcm,bcm7278-rng2000", },
>>>> +       { .compatible = "brcm,iproc-rng2000", },
>>>
>>> What is this change for?
>> This driver accelerates the initialization of the entropy pool. If this
>> dirver is added, the optimization effect of my patch will no longer be
>> clearly observable.
> 
> Great, obviously your patch is not needed!
> 
>>
>>>
>>>
>>>>           {},
>>>>    };
>>>>    MODULE_DEVICE_TABLE(of, iproc_rng200_of_match);
>>>> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
>>>> index 331646d667b9..13308d58785d 100644
>>>> --- a/drivers/of/fdt.c
>>>> +++ b/drivers/of/fdt.c
>>>> @@ -1100,7 +1100,7 @@ int __init early_init_dt_scan_chosen(char *cmdline)
>>>>
>>>>           rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l);
>>>>           if (rng_seed && l > 0) {
>>>> -               add_bootloader_randomness(rng_seed, l);
>>>> +               //add_bootloader_randomness(rng_seed, l);
>>>
>>> Why did you comment this out?
>> Before the kernel boots, the Raspberry Pi bootloader injects the rng-seed
>> property into the kernel's Device Tree to accelerate entropy pool
>> initialization. Therefore, I need to temporarily comment this out
>> to avoid interfering with the testing of my current patch.
> 
> Again, that seems like the correct fix, don't change the common code
> path of all systems just because you don't want to accept the changes
> that have already been made for your platform to resolve this very
> issue!

I think there might be a misunderstanding. The code below adds entropy 
pool initialization, but this logic is missing in the PPI interrupt 
handler. I believe this was simply an accidental omission.
---------------------------
irqreturn_t handle_irq_event_percpu(struct irq_desc *desc)
{
	irqreturn_t retval;

	retval = __handle_irq_event_percpu(desc);

	add_interrupt_randomness(desc->irq_data.irq);

	if (!irq_settings_no_debug(desc))
		note_interrupt(desc, retval);
	return retval;
}
> 
> thanks,
> 
> greg k-h