[PATCH v2 07/11] PCI: MSI: Use never-managed version of pci_intx()

Philipp Stanner posted 11 patches 1 week, 2 days ago
[PATCH v2 07/11] PCI: MSI: Use never-managed version of pci_intx()
Posted by Philipp Stanner 1 week, 2 days ago
pci_intx() is a hybrid function which can sometimes be managed through
devres. To remove this hybrid nature from pci_intx(), it is necessary to
port users to either an always-managed or a never-managed version.

MSI sets up its own separate devres callback implicitly in
pcim_setup_msi_release(). This callback ultimately uses pci_intx(),
which is problematic since the callback of course runs on driver-detach.

That problem has last been described here:
https://lore.kernel.org/all/ee44ea7ac760e73edad3f20b30b4d2fff66c1a85.camel@redhat.com/

Replace the call to pci_intx() with one to the never-managed version
pci_intx_unmanaged().

Signed-off-by: Philipp Stanner <pstanner@redhat.com>
---
 drivers/pci/msi/api.c | 2 +-
 drivers/pci/msi/msi.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/msi/api.c b/drivers/pci/msi/api.c
index b956ce591f96..c95e2e7dc9ab 100644
--- a/drivers/pci/msi/api.c
+++ b/drivers/pci/msi/api.c
@@ -289,7 +289,7 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
 			 */
 			if (affd)
 				irq_create_affinity_masks(1, affd);
-			pci_intx(dev, 1);
+			pci_intx_unmanaged(dev, 1);
 			return 1;
 		}
 	}
diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c
index 3a45879d85db..53f13b09db50 100644
--- a/drivers/pci/msi/msi.c
+++ b/drivers/pci/msi/msi.c
@@ -268,7 +268,7 @@ EXPORT_SYMBOL_GPL(pci_write_msi_msg);
 static void pci_intx_for_msi(struct pci_dev *dev, int enable)
 {
 	if (!(dev->dev_flags & PCI_DEV_FLAGS_MSI_INTX_DISABLE_BUG))
-		pci_intx(dev, enable);
+		pci_intx_unmanaged(dev, enable);
 }
 
 static void pci_msi_set_enable(struct pci_dev *dev, int enable)
-- 
2.47.0
Re: [PATCH v2 07/11] PCI: MSI: Use never-managed version of pci_intx()
Posted by Thomas Gleixner 1 week ago
On Wed, Nov 13 2024 at 13:41, Philipp Stanner wrote:
> pci_intx() is a hybrid function which can sometimes be managed through
> devres. To remove this hybrid nature from pci_intx(), it is necessary to
> port users to either an always-managed or a never-managed version.
>
> MSI sets up its own separate devres callback implicitly in
> pcim_setup_msi_release(). This callback ultimately uses pci_intx(),
> which is problematic since the callback of course runs on driver-detach.
>
> That problem has last been described here:
> https://lore.kernel.org/all/ee44ea7ac760e73edad3f20b30b4d2fff66c1a85.camel@redhat.com/
>
> Replace the call to pci_intx() with one to the never-managed version
> pci_intx_unmanaged().
>
> Signed-off-by: Philipp Stanner <pstanner@redhat.com>

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>