diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index ac0557a305af..ea5bdf6107f6 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -192,11 +192,54 @@ static void pcie_clkpm_cap_init(struct pcie_link_state *link, int blacklist)
 	link->clkpm_disable = blacklist ? 1 : 0;
 }
 
+static int pcie_change_tls_to_gen1(struct pci_dev *parent)
+{
+	u16 reg16;
+	u32 reg32;
+	int ret;
+
+	/* Check if link speed can be forced to 2.5 GT/s */
+	pcie_capability_read_dword(parent, PCI_EXP_LNKCAP2, &reg32);
+	if (!(reg32 & PCI_EXP_LNKCAP2_SLS_2_5GB)) {
+		pci_err(parent, "ASPM: Bridge does not support changing Link Speed to 2.5 GT/s\n");
+		return -EOPNOTSUPP;
+	}
+
+	/* Force link speed to 2.5 GT/s */
+	ret = pcie_capability_clear_and_set_word(parent, PCI_EXP_LNKCTL2,
+						 PCI_EXP_LNKCTL2_TLS,
+						 PCI_EXP_LNKCTL2_TLS_2_5GT);
+	if (ret == 0) {
+		/* Verify that new value was really set */
+		pcie_capability_read_word(parent, PCI_EXP_LNKCTL2, &reg16);
+		if ((reg16 & PCI_EXP_LNKCTL2_TLS) != PCI_EXP_LNKCTL2_TLS_2_5GT)
+			ret = -EINVAL;
+	}
+
+	if (ret != 0)
+		pci_err(parent, "ASPM: Changing Target Link Speed to 2.5 GT/s failed: %d\n", ret);
+
+	return ret;
+}
+
 static bool pcie_retrain_link(struct pcie_link_state *link)
 {
 	struct pci_dev *parent = link->pdev;
 	unsigned long end_jiffies;
 	u16 reg16;
+	u32 reg32;
+
+	if (link->downstream->dev_flags & PCI_DEV_FLAGS_NO_RETRAIN_LINK_WHEN_NOT_GEN1) {
+		/* Check if link is capable of higher speed than 2.5 GT/s and needs quirk */
+		pcie_capability_read_dword(parent, PCI_EXP_LNKCAP, &reg32);
+		if ((reg32 & PCI_EXP_LNKCAP_SLS) > PCI_EXP_LNKCAP_SLS_2_5GB) {
+			if (pcie_change_tls_to_gen1(parent) != 0) {
+				pci_err(parent, "ASPM: Retrain Link at higher speed is disallowed by quirk\n");
+				return false;
+			}
+			pci_info(parent, "ASPM: Target Link Speed changed to 2.5 GT/s due to quirk\n");
+		}
+	}
 
 	pcie_capability_read_word(parent, PCI_EXP_LNKCTL, &reg16);
 	reg16 |= PCI_EXP_LNKCTL_RL;
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 653660e3ba9e..8ff690c7679d 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3558,6 +3558,11 @@ static void quirk_no_bus_reset(struct pci_dev *dev)
 	dev->dev_flags |= PCI_DEV_FLAGS_NO_BUS_RESET;
 }
 
+static void quirk_no_bus_reset_and_no_retrain_link(struct pci_dev *dev)
+{
+	dev->dev_flags |= PCI_DEV_FLAGS_NO_BUS_RESET | PCI_DEV_FLAGS_NO_RETRAIN_LINK_WHEN_NOT_GEN1;
+}
+
 /*
  * Some Atheros AR9xxx and QCA988x chips do not behave after a bus reset.
  * The device will throw a Link Down error on AER-capable systems and
@@ -3567,10 +3572,18 @@ static void quirk_no_bus_reset(struct pci_dev *dev)
  */
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x0030, quirk_no_bus_reset);
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x0032, quirk_no_bus_reset);
-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);
 
+/*
+ * Atheros QCA9880 and QCA9890 chips do not behave after a bus reset and also
+ * after retrain link when PCIe bridge is not in GEN1 mode at 2.5 GT/s speed.
+ * The device will throw a Link Down error and config space is not accessible
+ * again. Retrain link can be called only when using GEN1 PCIe bridge or when
+ * PCIe bridge has forced link speed to 2.5 GT/s via PCI_EXP_LNKCTL2 register.
+ */
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x003c, quirk_no_bus_reset_and_no_retrain_link);
+
 /*
  * Root port on some Cavium CN8xxx chips do not successfully complete a bus
  * reset when used with certain child devices.  After the reset, config
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 86c799c97b77..fdbf7254e4ab 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -227,6 +227,8 @@ enum pci_dev_flags {
 	PCI_DEV_FLAGS_NO_FLR_RESET = (__force pci_dev_flags_t) (1 << 10),
 	/* Don't use Relaxed Ordering for TLPs directed at this device */
 	PCI_DEV_FLAGS_NO_RELAXED_ORDERING = (__force pci_dev_flags_t) (1 << 11),
+	/* Don't Retrain Link for device when bridge is not in GEN1 mode */
+	PCI_DEV_FLAGS_NO_RETRAIN_LINK_WHEN_NOT_GEN1 = (__force pci_dev_flags_t) (1 << 12),
 };
 
 enum pci_irq_reroute_variant {
