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From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     =?UTF-8?q?Antti=20J=C3=A4rvinen?= <antti.jarvinen@gmail.com>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Kishon Vijay Abraham I <kishon@ti.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: [PATCH 4.14 49/88] PCI: Mark TI C667X to avoid bus reset
Date:   Mon, 28 Jun 2021 10:35:49 -0400
Message-Id: <20210628143628.33342-50-sashal@kernel.org>
In-Reply-To: <20210628143628.33342-1-sashal@kernel.org>
References: <20210628143628.33342-1-sashal@kernel.org>
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From: Antti Järvinen <antti.jarvinen@gmail.com>

commit b5cf198e74a91073d12839a3e2db99994a39995d upstream.

Some TI KeyStone C667X devices do not support bus/hot reset.  The PCIESS
automatically disables LTSSM when Secondary Bus Reset is received and
device stops working.  Prevent bus reset for these devices.  With this
change, the device can be assigned to VMs with VFIO, but it will leak state
between VMs.

Reference: https://e2e.ti.com/support/processors/f/791/t/954382
Link: https://lore.kernel.org/r/20210315102606.17153-1-antti.jarvinen@gmail.com
Signed-off-by: Antti Järvinen <antti.jarvinen@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kishon Vijay Abraham I <kishon@ti.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/pci/quirks.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 510cb05aa96f..f0cd8f7ce881 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3402,6 +3402,16 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x003c, quirk_no_bus_reset);
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x0033, quirk_no_bus_reset);
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x0034, 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
+ * the device stops working.  Prevent bus reset for these devices.  With
+ * this change, the device can be assigned to VMs with VFIO, but it will
+ * leak state between VMs.  Reference
+ * https://e2e.ti.com/support/processors/f/791/t/954382
+ */
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_TI, 0xb005, quirk_no_bus_reset);
+
 static void quirk_no_pm_reset(struct pci_dev *dev)
 {
 	/*
-- 
2.30.2