Re: [PATCH v3 14/18] PCI: rcar-gen4: Route Root Port AER to a virtual Root Port IRQ

[sashiko-bot@kernel.org]

> On R-Car Gen4 SoCs, the APP block exposes the Root Port interrupt
> signals in PCIEINTSTS0 and routes them to platform IRQs: AER to
> intreq_pcim_lperr, and PME and bandwidth notifications to
> intreq_pcim_sub. On an R-Car S4 with GIC ITS, a link retrain set
> LnkSta.LBMS and latched PCIEINTSTS0[23] (cfg_bw_mgt_msi), but the Root
> Port's MSI never fired while endpoint MSIs worked fine. With iMSI-RX the
> Root Port MSI capabilities are already hidden, but its INTx maps to
> intreq_pcim_sub. Note that even before this driver took over the IRQ
> with rcar_gen4_pcie_msi_irq_handler, the port service was unable to
> request it, as the DWC core used that IRQ for its chained MSI handler.
> In either case, iMSI-RX or an external MSI controller, Root Port
> interrupts are not delivered to the port services.
> 
> Set no_rp_msi so the Root Port services use INTx regardless of the MSI
> controller. Use a virtual IRQ to deliver notifications from separate
> [ ... ]
> disabled, so the level parents can retry through the reset checks.
> This avoids losing notifications without a raw lock around port
> services that take regular spinlocks.
> 
> Signed-off-by: Koichiro Den <den@valinux.co.jp>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20261006084638.3821710-1-den@valinux.co.jp?part=14