On Tue, Jun 08, 2021 at 10:04:09AM +0200, Javier Martinez Canillas wrote: > IRQ handlers that are registered for shared interrupts can be called at > any time after have been registered using the request_irq() function. > > It's up to drivers to ensure that's always safe for these to be called. > > Both the "pcie-sys" and "pcie-client" interrupts are shared, but since > their handlers are registered very early in the probe function, an error > later can lead to these handlers being executed before all the required > resources have been properly setup. > > For example, the rockchip_pcie_read() function used by these IRQ handlers > expects that some PCIe clocks will already be enabled, otherwise trying > to access the PCIe registers causes the read to hang and never return. The read *never* completes? That might be a bit problematic because it implies that we may not be able to recover from PCIe errors. Most controllers will timeout eventually, log an error, and either fabricate some data (typically ~0) to complete the CPU's read or cause some kind of abort or machine check. Just asking in case there's some controller configuration that should be tweaked.
