r8169: avoid unsolicited interrupts

[ Upstream commit 10ce0db787004875f4dba068ea952207d1d8abeb ]

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: 0e4851502f84 ("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 <atlas.yu@canonical.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/78e2f535-438f-4212-ad94-a77637ac6c9c@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index e9296d63450d854dd8f8bba8c8e1301f68615d6a..3aa1dda3406cd80efb3d0d06914f7fb04cd6b89a 100644 (file)
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -4650,7 +4650,9 @@ 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;
        }