On Wed, 06 Jul 2022 09:19:01 +0100, Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx> wrote: > > On Wed, Jul 06, 2022 at 08:05:30AM +0100, Marc Zyngier wrote: > > On Sun, 03 Jul 2022 19:15:11 +0100, > > Sander Vanheule <sander@xxxxxxxxxxxxx> wrote: > > > > > > Hi Aleksander, > > > > > > Since this is IRQ related: +CC Marc Zyngier > > > > > > On Sat, 2022-07-02 at 21:07 +0200, Aleksander Jan Bajkowski wrote: > > > > This patch is needed to handle interrupts by the second VPE on > > > > the Lantiq xRX200, xRX300 and xRX330 SoCs. In these chips, 32 ICU > > > > interrupts are connected to each hardware line. The SoC supports > > > > a total of 160 interrupts. Currently changing smp_affinity to the > > > > second VPE hangs interrupts. > > > > > > > > This problem affects multithreaded SoCs with a custom interrupt > > > > controller. Chips with 1004Kc core and newer use the MIPS GIC. > > > > > > > > Also CC'ed Birger Koblitz and Sander Vanheule. Both are working > > > > on support for Realtek RTL930x chips with 34Kc core and Birger > > > > has added a patch in OpenWRT that also enables all interrupt > > > > lines. So it looks like this patch is useful for more SoCs. > > > > > > > > Tested on lantiq xRX200 and xRX330. > > > > > > > > Signed-off-by: Aleksander Jan Bajkowski <olek2@xxxxx> > > > > > > Thanks for bringing up this issue. Like you say OpenWrt carries a > > > similar patch, and I also carry a patch on my tree to enable all CPU > > > IRQ lines. > > > > > > Indiscriminately enabling all IRQ lines doesn't sit quite right with > > > me though, since I would expect these to be enabled > > > on-demand. I.e. when a peripheral requests an IRQ, or when an IRQ > > > controller is cascaded into one of the CPU's interrupt lines. If I > > > understand correctly, the IRQ mask/unmask functions in > > > drivers/irqchip/irq-mips-cpu.c should do this. > > > > But this is only enabling interrupts at the CPU level, right? And the > > irqchip is still in control of the masking of the individual > > interrupts? > > in the Lantiq case yes > > > If both assertions are true, then this patch seems OK. If it just let > > any interrupt through without any control, then this is wrong. > > > > So which one is it? > > if there isn't an additional irqchip connected to the cpu interrupt lines, > this patch will cause problems. And that's what the irq-mips-cpu driver should solve, right? In this case, what's the problem with adopting this driver for the Lantiq platform (and all other ones using the same CPU)? M. -- Without deviation from the norm, progress is not possible.
