PCI: dw-rockchip: Move INTx IRQ setup to probe

Since commit b376b3ff9cb0 ("PCI: dw-rockchip: Implement .reset_root_port()
and use for link down"), .reset_root_port() re-runs the host ops .init()
callback to reprogram the Root Complex after a controller reset. That
works for the register programming, but .init() is not re-entrant: it
also creates the INTx IRQ domain and installs the chained INTx handler.
Every Root Port reset therefore ends up with a second IRQ domain
registered for the same fwnode: the previous one is leaked, as it is
never removed, and worse, the INTx virqs of the downstream PCI devices
were allocated in the previous IRQ domain and are never re-mapped, while
the chained handler now looks up virqs in the new, empty domain. After a
link down recovery, INTx interrupts are silently lost.

Fix it by moving the of_irq_get_byname() lookup, the INTx IRQ domain
creation and the chained handler installation out of .init() and into
rockchip_pcie_configure_rc(), just before dw_pcie_host_init(). The
lookup has to happen before the host is initialized, because
dw_pcie_host_init() enumerates the bus and probes the downstream
devices, and pci_assign_irq() maps their INTx interrupts at that point:
if the domain does not exist yet, the mapping fails and the devices end
up without a usable INTx. This also mirrors how the qcom driver requests
its global IRQ, and leaves .init() with nothing but idempotent register
programming, so both .reset_root_port() and dw_pcie_resume_noirq() can
safely re-run it. Re-running of_irq_get_byname() on every resume is also
gone.

Fixes: b376b3ff9cb0 ("PCI: dw-rockchip: Implement .reset_root_port() and use for link down")
Suggested-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Diederik de Haas <diederik@cknow-tech.com>  # NanoPC-T6 Plus
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Link: https://patch.msgid.link/1790222793-77182-1-git-send-email-shawn.lin@rock-chips.com

0 files changed, 0 insertions, 0 deletions