[PATCH v2] rtlwifi: rtl8723be: Disable ASPM if RTL8723BE connects to Intel PCI bridge

[Jian-Hong Pan]

Disable rtl8723be's ASPM if the Realtek RTL8723BE PCIe Wireless adapter
connects to some Intel PCI bridges, such as Skylake and Kabylake.
Otherwise, the PCI AER flood hangs system:

pcieport 0000:00:1c.5: PCIe Bus Error: severity=Corrected, type=Physical Layer, (Receiver ID)
pcieport 0000:00:1c.5:   device [8086:9d15] error status/mask=00000001/00002000
pcieport 0000:00:1c.5:    [ 0] RxErr                  (First)
pcieport 0000:00:1c.5: AER: Corrected error received: 0000:00:1c.5
pcieport 0000:00:1c.5: AER: can't find device of ID00e5
pcieport 0000:00:1c.5: AER: Corrected error received: 0000:00:1c.5
pcieport 0000:00:1c.5: AER: can't find device of ID00e5
pcieport 0000:00:1c.5: AER: Multiple Corrected error received: 0000:00:1c.5
pcieport 0000:00:1c.5: AER: can't find device of ID00e5

Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=218127
Signed-off-by: Jian-Hong Pan <jhp@xxxxxxxxxxxxx>
---
v2: Add the switch case's default condition with comment:
    "The ASPM has already been enabled by initializing
    rtl8723be_mod_params' aspm_support as 1."

 .../wireless/realtek/rtlwifi/rtl8723be/sw.c   | 24 +++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8723be/sw.c b/drivers/net/wireless/realtek/rtlwifi/rtl8723be/sw.c
index 43b611d5288d..b20c0b9d8393 100644
--- a/drivers/net/wireless/realtek/rtlwifi/rtl8723be/sw.c
+++ b/drivers/net/wireless/realtek/rtlwifi/rtl8723be/sw.c
@@ -25,10 +25,34 @@ static void rtl8723be_init_aspm_vars(struct ieee80211_hw *hw)
 {
 	struct rtl_priv *rtlpriv = rtl_priv(hw);
 	struct rtl_pci *rtlpci = rtl_pcidev(rtl_pcipriv(hw));
+	struct pci_dev *bridge_pdev;
 
 	/*close ASPM for AMD defaultly */
 	rtlpci->const_amdpci_aspm = 0;
 
+	/* Disable ASPM if RTL8723BE connects to some Intel PCI bridges, such as
+	 * Skylake and Kabylake. Otherwise, the PCI AER flood hangs system.
+	 */
+	bridge_pdev = rtlpci->pdev->bus->self;
+	if (bridge_pdev->vendor == PCI_VENDOR_ID_INTEL) {
+		switch(bridge_pdev->device) {
+		case 0x9d15:
+		/* PCI bridges on Skylake */
+		case 0xa110 ... 0xa11f:
+		case 0xa167 ... 0xa16a:
+		/* PCI bridges on Kabylake */
+		case 0xa290 ... 0xa29f:
+		case 0xa2e7 ... 0xa2ee:
+			rtlpriv->cfg->mod_params->aspm_support = 0;
+			break;
+		default:
+			/* The ASPM has already been enabled by initializing
+			 * rtl8723be_mod_params' aspm_support as 1.
+			 */
+			break;
+		}
+	}
+
 	/* ASPM PS mode.
 	 * 0 - Disable ASPM,
 	 * 1 - Enable ASPM without Clock Req,
-- 
2.42.1