[PATCH net] 8139cp: fix Rx and Tx not being disabled in cp_suspend

From: Karl Mehltretter

Date: Mon Aug 17 2026 - 00:32:27 EST


On QEMU rtl8139 model, frames that arrive while the interface is
suspended still end up in the stack after resume. With pm_test=devices,
which keeps devices suspended for 5s, 200 frames sent to interface
during that time and 50 frames after resume, eth0 reports 113
received frames.

cp_suspend() is supposed to stop receiver and the transmitter, but
the mask is wrong: (~RxOn | ~TxOn) is ~0, nothing is cleared and Cmd
still reads 0x0d when cp_suspend() returns.

Use ~(RxOn | TxOn) so both bits are actually cleared.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Karl Mehltretter <kmehltretter@xxxxxxxxx>
---
drivers/net/ethernet/realtek/8139cp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/realtek/8139cp.c b/drivers/net/ethernet/realtek/8139cp.c
index 5652da8a178c0..9016527e229ac 100644
--- a/drivers/net/ethernet/realtek/8139cp.c
+++ b/drivers/net/ethernet/realtek/8139cp.c
@@ -2066,7 +2066,7 @@ static int __maybe_unused cp_suspend(struct device *device)

/* Disable Rx and Tx */
cpw16 (IntrMask, 0);
- cpw8 (Cmd, cpr8 (Cmd) & (~RxOn | ~TxOn));
+ cpw8 (Cmd, cpr8 (Cmd) & ~(RxOn | TxOn));

spin_unlock_irqrestore (&cp->lock, flags);


base-commit: 3eb40771c00a8488fa6ed2cc1fe203477908bf38
--
2.53.0