[PATCH 4.14 17/21] PCI: Avoid FLR for SolidRun SNET DPU rev 1

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Alvaro Karsz <alvaro.karsz@solid-run.com>

[ Upstream commit d089d69cc1f824936eeaa4fa172f8fa1a0949eaa ]

This patch fixes a FLR bug on the SNET DPU rev 1 by setting the
PCI_DEV_FLAGS_NO_FLR_RESET flag.

As there is a quirk to avoid FLR (quirk_no_flr), I added a new quirk
to check the rev ID before calling to quirk_no_flr.

Without this patch, a SNET DPU rev 1 may hang when FLR is applied.

Signed-off-by: Alvaro Karsz <alvaro.karsz@solid-run.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Message-Id: <20230110165638.123745-3-alvaro.karsz@solid-run.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/pci/quirks.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index b9fedf9c77cb9..d0bff9a9f9a9c 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -5068,6 +5068,14 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_AMD, 0x7901, quirk_no_flr);
 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1502, quirk_no_flr);
 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1503, quirk_no_flr);
 
+/* FLR may cause the SolidRun SNET DPU (rev 0x1) to hang */
+static void quirk_no_flr_snet(struct pci_dev *dev)
+{
+	if (dev->revision == 0x1)
+		quirk_no_flr(dev);
+}
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SOLIDRUN, 0x1000, quirk_no_flr_snet);
+
 static void quirk_no_ext_tags(struct pci_dev *pdev)
 {
 	struct pci_host_bridge *bridge = pci_find_host_bridge(pdev->bus);
-- 
2.39.2