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

["Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>]

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On Thu, 14 Nov 2024, Ilpo Järvinen wrote:

> 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")

This should be:

Fixes: 058a4cb11620 ("PCI/bwctrl: Re-add BW notification portdrv as PCIe BW controller")

(I wasn't thinking and used the local commit id instead of the one from 
pci repo.)

> Reported-by: Stefan Wahren <wahrenst@gmx.net>
> Link: https://lore.kernel.org/linux-pci/dcd660fd-a265-4f47-8696-776a85e097a0@gmx.net/
> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
> ---
>  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;
> 

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 i.