Linux PCI subsystem development
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From: Marcos Del Sol Vives <marcos@orca.pet>
To: linux-kernel@vger.kernel.org
Cc: marcos@orca.pet, Bjorn Helgaas <bhelgaas@google.com>,
	linux-pci@vger.kernel.org
Subject: [PATCH] pci: disable MSI on RDC PCI to PCI-E bridges
Date: Sun,  6 Jul 2025 01:32:08 +0200	[thread overview]
Message-ID: <20250705233209.721507-1-marcos@orca.pet> (raw)

These bridges, present on Vortex86DX3 and Vortex86EX2 SoCs, do not
support MSIs. If enabled, interrupts generated by PCI-E devices never
reach the processor.

I have contacted the manufacturer (DM&P) and they confirmed that PCI MSIs
need to be disabled for them.

Signed-off-by: Marcos Del Sol Vives <marcos@orca.pet>
---
 drivers/pci/quirks.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index d7f4ee634263..f610ea45ca9e 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -2715,6 +2715,7 @@ static void quirk_disable_msi(struct pci_dev *dev)
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_8131_BRIDGE, quirk_disable_msi);
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_VIA, 0xa238, quirk_disable_msi);
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x5a3f, quirk_disable_msi);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_RDC, 0x1031, quirk_disable_msi);
 
 /*
  * The APC bridge device in AMD 780 family northbridges has some random
-- 
2.34.1


             reply	other threads:[~2025-07-05 23:49 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-07-05 23:32 Marcos Del Sol Vives [this message]
2025-08-06 21:23 ` [PATCH] pci: disable MSI on RDC PCI to PCI-E bridges Bjorn Helgaas

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