Commit 00f89ae4 authored by Philipp Stanner's avatar Philipp Stanner Committed by Bjorn Helgaas
Browse files

PCI: Fix devres regression in pci_intx() 

pci_intx() becomes managed if pcim_enable_device() has been called in
advance. Commit 25216afc ("PCI: Add managed pcim_intx()") changed this
behavior so that pci_intx() always leads to creation of a separate device
resource for itself, whereas earlier, a shared resource was used for all
PCI devres operations.

Unfortunately, pci_intx() seems to be used in some drivers' remove() paths;
in the managed case this causes a device resource to be created on driver
detach, which causes .probe() to fail if the driver is reloaded:

  pci 0000:00:1f.2: Resources present before probing

Fix the regression by only redirecting pci_intx() to its managed twin
pcim_intx() if the pci_command changes.

Link: https://lore.kernel.org/r/20240725120729.59788-2-pstanner@redhat.com


Fixes: 25216afc ("PCI: Add managed pcim_intx()")
Reported-by: default avatarDamien Le Moal <dlemoal@kernel.org>
Closes: https://lore.kernel.org/all/b8f4ba97-84fc-4b7e-ba1a-99de2d9f0118@kernel.org/


Signed-off-by: default avatarPhilipp Stanner <pstanner@redhat.com>
[bhelgaas: add error message to commit log]
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Tested-by: default avatarDamien Le Moal <dlemoal@kernel.org>
parent 8400291e

drivers/pci/pci.c

+8 −7
Original line number Diff line number Diff line
@@ -4477,12 +4477,6 @@ void pci_intx(struct pci_dev *pdev, int enable) 
{

	u16 pci_command, new;



	/* Preserve the "hybrid" behavior for backwards compatibility */

	if (pci_is_managed(pdev)) {

		WARN_ON_ONCE(pcim_intx(pdev, enable) != 0);

		return;

	}



	pci_read_config_word(pdev, PCI_COMMAND, &pci_command);



	if (enable)
@@ -4490,9 +4484,16 @@ void pci_intx(struct pci_dev *pdev, int enable) 
	else

		new = pci_command | PCI_COMMAND_INTX_DISABLE;



	if (new != pci_command)

	if (new != pci_command) {

		/* Preserve the "hybrid" behavior for backwards compatibility */

		if (pci_is_managed(pdev)) {

			WARN_ON_ONCE(pcim_intx(pdev, enable) != 0);

			return;

		}



		pci_write_config_word(pdev, PCI_COMMAND, new);

	}

}

EXPORT_SYMBOL_GPL(pci_intx);



/**