Re: [PATCH] mailbox: pcc: Free the channel before unmapping the shared memory

[Sudeep Holla]

On Thu, Aug 13, 2026 at 01:18:58AM -0700, Breno Leitao wrote:
> Hello Sudeep,
> 
> On Thu, Aug 13, 2026 at 03:57:29AM +0100, Sudeep Holla wrote:
> > On Wed, Aug 12, 2026 at 05:36:03AM -0700, Breno Leitao wrote:
> > > I am seeing a crash on PCC that is related to a an shared memory being
> > > unmapped before the IRQ is disabled, and the IRQ kicks in and hits the
> > > unmapped (NULL) address. This is a summary of what I see on my box:
> > > 
> > > 	scmi_protocol scmi_dev.1: Message for 1 type 0 is not expected!
> > > 	Unable to handle kernel NULL pointer dereference at virtual address 0000000000000004
> > > 	 __handle_irq_event_percpu+0x1c4/0x9e0
> > > 	 handle_irq_event+0x98/0x218
> > > 	 handle_fasteoi_irq+0x230/0x750
> > > 	 generic_handle_domain_irq+0xac/0x138
> > > 	 gic_handle_irq+0x344/0x740
> > > 	 call_on_irq_stack+0x30/0x48
> > > 
> > 
> > Just curious as how are you testing ACPI PCC + SCMI using upstream and
> > on which platform ?
> 
> I am using Arm AGI CPU with the latest SCMI patches that are being under
> discussion in the mailing list.
> 

Thanks, I just wanted to rule out any hidden issues in the ACPI PCC driver
I wrote which hasn't got much review 😉.

-- 
Regards,
Sudeep