[PATCH 1/1] PCI/PME+pciehp: Request IRQF_ONESHOT because bwctrl shares IRQ

[Ilpo Järvinen]

PCIe BW controller uses IRQF_ONESHOT to solve the problem fixed by the
commit 3e82a7f9031f ("PCI/LINK: Supply IRQ handler so level-triggered
IRQs are acked"). The IRQ is shared with PME and PCIe hotplug. Due to
probe order, PME and hotplug can request IRQ first without IRQF_ONESHOT
and when BW controller requests IRQ later with IRQF_ONESHOT, the IRQ
request fails. The problem is seen at least on Rasperry Pi 4:

pcieport 0000:00:00.0: PME: Signaling with IRQ 39
pcieport 0000:00:00.0: AER: enabled with IRQ 39
genirq: Flags mismatch irq 39. 00002084 (PCIe bwctrl) vs.00200084 (PCIe PME)
pcie_bwctrl 0000:00:00.0:pcie010: probe with driver pcie_bwctrl failed with error -16

BW controller is always enabled so change PME and pciehp too to use
IRQF_ONESHOT.

Fixes: 470b218c2bdf ("PCI/bwctrl: Re-add BW notification portdrv as PCIe BW controller")
Reported-by: Stefan Wahren <wahrenst@xxxxxxx>
Link: https://lore.kernel.org/linux-pci/dcd660fd-a265-4f47-8696-776a85e097a0@xxxxxxx/
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
---
 drivers/pci/hotplug/pciehp_hpc.c | 3 ++-
 drivers/pci/pcie/pme.c           | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 736ad8baa2a5..0778305cff9d 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -68,7 +68,8 @@ static inline int pciehp_request_irq(struct controller *ctrl)
 
 	/* Installs the interrupt handler */
 	retval = request_threaded_irq(irq, pciehp_isr, pciehp_ist,
-				      IRQF_SHARED, "pciehp", ctrl);
+				      IRQF_SHARED | IRQF_ONESHOT,
+				      "pciehp", ctrl);
 	if (retval)
 		ctrl_err(ctrl, "Cannot get irq %d for the hotplug controller\n",
 			 irq);
diff --git a/drivers/pci/pcie/pme.c b/drivers/pci/pcie/pme.c
index a2daebd9806c..04f0e5a7b74c 100644
--- a/drivers/pci/pcie/pme.c
+++ b/drivers/pci/pcie/pme.c
@@ -347,7 +347,8 @@ static int pcie_pme_probe(struct pcie_device *srv)
 	pcie_pme_interrupt_enable(port, false);
 	pcie_clear_root_pme_status(port);
 
-	ret = request_irq(srv->irq, pcie_pme_irq, IRQF_SHARED, "PCIe PME", srv);
+	ret = request_irq(srv->irq, pcie_pme_irq, IRQF_SHARED | IRQF_ONESHOT,
+			  "PCIe PME", srv);
 	if (ret) {
 		kfree(data);
 		return ret;
-- 
2.39.5