Messages in this thread | | | Subject | Re: [PATCH v2 1/3] genirq/affinity: Add irq_update_affinity_desc() | From | John Garry <> | Date | Thu, 26 Nov 2020 10:47:33 +0000 |
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Hi Marc,
>> Right, I did consider this. > > FWIW, I've pushed my hack branch[1]
Did you miss that reference?
> out with a couple of patches > for you to try (the top 3 patches). They allow platform-MSI domains > created by devices (mbigen, ICU) to be advertised as shared between > devices, so that the low-level driver can handle that in an appropriate > way. > > I gave it a go on my D05 and nothing blew up, but I can't really remove > the kernel module, as that's where my disks are... :-/
You still should be able to enable my favorite CONFIG_DEBUG_TEST_DRIVER_REMOVE=y, while the distro still boot. But I'll just test if you want.
> Please let me know if that helps. > >>> It is just that passing that information down isn't a simple affair, >>> as msi_alloc_info_t isn't a generic type... Let me have a think. >> >> I think that there is a way to circumvent the problem, which you might >> call hacky, but OTOH, not sure if there's much point changing mbigen >> or related infrastructure at this stage. > > Bah, it's a simple change, and there is now more than the mbigen using > the same API... > >> >> Anyway, so we have 128 irqs in total for the mbigen domain, but the >> driver only is interesting in something like irq indexes 1,2,72-81, >> and 96-112. So we can just dispose the mappings for irq index 0-112 at >> removal stage, thereby keeping the its device around. We do still call >> platform_irq_count(), which sets up all 128 mappings, so maybe we >> should be unmapping all of these - this would be the contentious part. >> But maybe not, as the device driver is only interested in that subset, >> and has no business unmapping the rest. > > I don't think the driver should mess with interrupts it doesn't own.
I would tend to agree. But all 128 lines here are for the SAS controller. It's quite strange, as only about ~20 are useful.
> And while the mbigen port that is connected to the SAS controller > doesn't seem to be shared between endpoints, some other ports definitely > are: > > # cat /sys/kernel/debug/irq/domains/\\_SB.MBI1 > name: \_SB.MBI1 > size: 409 > mapped: 192 > flags: 0x00000003 > > [...] > > I guess that the other 217 lines are connected somewhere. >
I think that is not the right one. See https://github.com/tianocore/edk2-platforms/blob/master/Silicon/Hisilicon/Hi1616/D05AcpiTables/Dsdt/D05Sas.asl#L101
Thanks, John
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