From 6c72e65d57dc2a7d811f76a126a9a006abd0ab75 Mon Sep 17 00:00:00 2001
From: fangying <fangying1@huawei.com>
Date: Wed, 18 Mar 2020 12:51:33 +0800
Subject: [PATCH] pcie: Compat with devices which do not support Link Width,
 such as ioh3420

We hack into PCI_EXP_LNKCAP to support device fast plug/unplug
for pcie-root-port. However some devices like ioh3420 does not
suport it, so PCI_EXP_LNKCAP is not set for such devices.

Signed-off-by: Ying Fang <fangying1@huawei.com>
Signed-off-by: Yan Wang <wangyan122@huawei.com>
---
 hw/pci/pcie.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
index 6db0cf69cd..dccf204451 100644
--- a/hw/pci/pcie.c
+++ b/hw/pci/pcie.c
@@ -97,13 +97,6 @@ static void pcie_cap_fill_slot_lnk(PCIDevice *dev)
         return;
     }
 
-    /* Clear and fill LNKCAP from what was configured above */
-    pci_long_test_and_clear_mask(exp_cap + PCI_EXP_LNKCAP,
-                                 PCI_EXP_LNKCAP_MLW | PCI_EXP_LNKCAP_SLS);
-    pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP,
-                               QEMU_PCI_EXP_LNKCAP_MLW(s->width) |
-                               QEMU_PCI_EXP_LNKCAP_MLS(s->speed));
-
     /*
      * Link bandwidth notification is required for all root ports and
      * downstream ports supporting links wider than x1 or multiple link
@@ -111,6 +104,12 @@ static void pcie_cap_fill_slot_lnk(PCIDevice *dev)
      */
     if (s->width > QEMU_PCI_EXP_LNK_X1 ||
         s->speed > QEMU_PCI_EXP_LNK_2_5GT) {
+        /* Clear and fill LNKCAP from what was configured above */
+        pci_long_test_and_clear_mask(exp_cap + PCI_EXP_LNKCAP,
+                                 PCI_EXP_LNKCAP_MLW | PCI_EXP_LNKCAP_SLS);
+        pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP,
+                               QEMU_PCI_EXP_LNKCAP_MLW(s->width) |
+                               QEMU_PCI_EXP_LNKCAP_MLS(s->speed));
         pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP,
                                    PCI_EXP_LNKCAP_LBNC);
     }
-- 
2.27.0