[PATCH net] amd-xgbe: Enable IRQs only if napi_complete_done() is true

[Tom Lendacky]

Depending on the hardware, the amd-xgbe driver may use disable_irq_nosync()
and enable_irq() when an interrupt is received to process Rx packets. If
the napi_complete_done() return value isn't checked an unbalanced enable
for the IRQ could result, generating a warning stack trace.

Update the driver to only enable interrupts if napi_complete_done() returns
true.

Reported-by: Jeremy Linton <jeremy.lin...@arm.com>
Signed-off-by: Tom Lendacky <thomas.lenda...@amd.com>
---
 drivers/net/ethernet/amd/xgbe/xgbe-drv.c |   10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c 
b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
index 248f60d..ffea985 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
@@ -2272,10 +2272,7 @@ static int xgbe_one_poll(struct napi_struct *napi, int 
budget)
        processed = xgbe_rx_poll(channel, budget);
 
        /* If we processed everything, we are done */
-       if (processed < budget) {
-               /* Turn off polling */
-               napi_complete_done(napi, processed);
-
+       if ((processed < budget) && napi_complete_done(napi, processed)) {
                /* Enable Tx and Rx interrupts */
                if (pdata->channel_irq_mode)
                        xgbe_enable_rx_tx_int(pdata, channel);
@@ -2317,10 +2314,7 @@ static int xgbe_all_poll(struct napi_struct *napi, int 
budget)
        } while ((processed < budget) && (processed != last_processed));
 
        /* If we processed everything, we are done */
-       if (processed < budget) {
-               /* Turn off polling */
-               napi_complete_done(napi, processed);
-
+       if ((processed < budget) && napi_complete_done(napi, processed)) {
                /* Enable Tx and Rx interrupts */
                xgbe_enable_rx_tx_ints(pdata);
        }