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

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Jun 16, 2026 at 03:40:10PM +0800, enlin.mu wrote:
> 
> 
> 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;

Look back at your original patch.  It contained none of this
information...