[PATCH v2] PCI/portdev: Disable AER for Titan Ridge 4C 2018

[Atharva Tiwari <atharvatiwarilinuxdev@gmail.com>]

Changes since v1:
	Transferred logic to drivers/pci/quicks.c

Disable AER for Intel Titan Ridge 4C 2018
(used in T2 iMacs, where the warnings appear)
that generate continuous pcieport warnings. such as:

pcieport 0000:00:1c.4: AER: Correctable error message received from 0000:07:00.0
pcieport 0000:07:00.0: PCIe Bus Error: severity=Correctable, type=Data Link Layer, (Receiver ID)
pcieport 0000:07:00.0:   device [8086:15ea] error status/mask=00000080/00002000
pcieport 0000:07:00.0:    [ 7] BadDLLP

(see: https://bugzilla.kernel.org/show_bug.cgi?id=220651)

macOS also disables AER for Thunderbolt devices and controllers in their drivers.

Signed-off-by: Atharva Tiwari <atharvatiwarilinuxdev@gmail.com>
---
 drivers/pci/pcie/aer.c     | 3 +++
 drivers/pci/pcie/portdrv.c | 2 +-
 drivers/pci/quirks.c       | 9 +++++++++
 include/linux/pci.h        | 1 +
 4 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index e0bcaa896803..45604564ce6f 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -389,6 +389,9 @@ void pci_aer_init(struct pci_dev *dev)
 {
 	int n;
 
+	if (dev->no_aer)
+		return;
+
 	dev->aer_cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
 	if (!dev->aer_cap)
 		return;
diff --git a/drivers/pci/pcie/portdrv.c b/drivers/pci/pcie/portdrv.c
index 38a41ccf79b9..ab904a224296 100644
--- a/drivers/pci/pcie/portdrv.c
+++ b/drivers/pci/pcie/portdrv.c
@@ -240,7 +240,7 @@ static int get_port_device_capability(struct pci_dev *dev)
 	if ((pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT ||
              pci_pcie_type(dev) == PCI_EXP_TYPE_RC_EC) &&
 	    dev->aer_cap && pci_aer_available() &&
-	    (pcie_ports_native || host->native_aer))
+	    (pcie_ports_native || host->native_aer) && !dev->no_aer)
 		services |= PCIE_PORT_SERVICE_AER;
 #endif
 
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index b9c252aa6fe0..d36dd3f8bbf6 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -6340,4 +6340,13 @@ static void pci_mask_replay_timer_timeout(struct pci_dev *pdev)
 }
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_GLI, 0x9750, pci_mask_replay_timer_timeout);
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_GLI, 0x9755, pci_mask_replay_timer_timeout);
+
+static void pci_disable_aer(struct pci_dev *pdev)
+{
+	pdev->no_aer = 1;
+}
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x15EA, pci_disable_aer);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x15EB, pci_disable_aer);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x15EC, pci_disable_aer);
+
 #endif
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 864775651c6f..f447f86c6bdf 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -440,6 +440,7 @@ struct pci_dev {
 	unsigned int	multifunction:1;	/* Multi-function device */
 
 	unsigned int	is_busmaster:1;		/* Is busmaster */
+	unsigned int	no_aer:1;		/* May not use AER */
 	unsigned int	no_msi:1;		/* May not use MSI */
 	unsigned int	no_64bit_msi:1;		/* May only use 32-bit MSIs */
 	unsigned int	block_cfg_access:1;	/* Config space access blocked */
-- 
2.43.0