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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org,
	stable@vger.kernel.org
Cc: Edmund Raile <edmund.raile@proton.me>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Sasha Levin <sashal@kernel.org>,
	linux-pci@vger.kernel.org
Subject: [PATCH AUTOSEL 6.6 52/75] PCI: Mark LSI FW643 to avoid bus reset
Date: Fri, 29 Mar 2024 08:42:33 -0400
Message-ID: <20240329124330.3089520-52-sashal@kernel.org>
In-Reply-To: <20240329124330.3089520-1-sashal@kernel.org>
References: <20240329124330.3089520-1-sashal@kernel.org>
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From: Edmund Raile <edmund.raile@proton.me>

[ Upstream commit 29a43dc130ce65d365a8ea9e1cc4bc51005a353e ]

Apparently the LSI / Agere FW643 can't recover after a Secondary Bus Reset
and requires a power-off or suspend/resume and rescan.

VFIO resets a device before assigning it to a VM, and the FW643 doesn't
support any other reset methods, so this problem prevented assignment of
FW643 to VMs.

Prevent use of Secondary Bus Reset for this device.

With this change, the FW643 can be assigned to VMs with VFIO.  Note that it
will not be reset, resulting in leaking state between VMs and host.

Link: https://lore.kernel.org/r/20240227131401.17913-1-edmund.raile@proton.me
Signed-off-by: Edmund Raile <edmund.raile@proton.me>
[bhelgaas: commit log, comment]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.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 b5b96d2a9f4ba..687f9b00b3057 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3758,6 +3758,14 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x003e, quirk_no_bus_reset);
  */
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_CAVIUM, 0xa100, quirk_no_bus_reset);
 
+/*
+ * Apparently the LSI / Agere FW643 can't recover after a Secondary Bus
+ * Reset and requires a power-off or suspend/resume and rescan.  Prevent
+ * use of that reset.
+ */
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATT, 0x5900, quirk_no_bus_reset);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATT, 0x5901, quirk_no_bus_reset);
+
 /*
  * Some TI KeyStone C667X devices do not support bus/hot reset.  The PCIESS
  * automatically disables LTSSM when Secondary Bus Reset is received and
-- 
2.43.0