r8169: avoid unsolicited interrupts

It was reported that after resume from suspend a PCI error is logged
and connectivity is broken. Error message is:
PCI error (cmd = 0x0407, status_errs = 0x0000)
The message seems to be a red herring as none of the error bits is set,
and the PCI command register value also is normal. Exception handling
for a PCI error includes a chip reset what apparently brakes connectivity
here. The interrupt status bit triggering the PCI error handling isn't
actually used on PCIe chip versions, so it's not clear why this bit is
set by the chip. Fix this by ignoring this bit on PCIe chip versions.

Fixes: 0e48515 ("r8169: merge with version 8.001.00 of Realtek's r8168 driver")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219388
Tested-by: Atlas Yu <[email protected]>
Signed-off-by: Heiner Kallweit <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>

Author: hkallweit

drivers/net/ethernet/realtek/r8169_main.c

@@ -4682,7 +4682,9 @@ static irqreturn_t rtl8169_interrupt(int irq, void *dev_instance)
 	if ((status & 0xffff) == 0xffff || !(status & tp->irq_mask))
 		return IRQ_NONE;
 
-	if (unlikely(status & SYSErr)) {
+	/* At least RTL8168fp may unexpectedly set the SYSErr bit */
+	if (unlikely(status & SYSErr &&
+	    tp->mac_version <= RTL_GIGA_MAC_VER_06)) {
 		rtl8169_pcierr_interrupt(tp->dev);
 		goto out;
 	}