net: ti: am65-cpsw-nuss: avoid errors due to imbalanced start()/stop()
The eth-uclass state machine doesn't prevent imbalanced start()/stop()
calls - to the contrary, it even provides eth_init_state_only() and
eth_halt_state_only() functions that change the state without any calls
into the driver. This means that the driver must be robust against
duplicate start() and stop() calls as well as send/recv calls while the
interface is down.
We decide not to print error messages but just to return an error in the
latter case, as trying to send packets on a disabled interface commonly
happens when the netconsole is still active after the Ethernet has been
halted during bootm.
Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
diff --git a/drivers/net/ti/am65-cpsw-nuss.c b/drivers/net/ti/am65-cpsw-nuss.c
index 335c8be..e0968f6 100644
--- a/drivers/net/ti/am65-cpsw-nuss.c
+++ b/drivers/net/ti/am65-cpsw-nuss.c
@@ -327,6 +327,9 @@
struct ti_udma_drv_chan_cfg_data *dma_rx_cfg_data;
int ret, i;
+ if (common->started)
+ return 0;
+
ret = power_domain_on(&common->pwrdmn);
if (ret) {
dev_err(dev, "power_domain_on() failed %d\n", ret);
@@ -487,6 +490,9 @@
struct ti_udma_drv_packet_data packet_data;
int ret;
+ if (!common->started)
+ return -ENETDOWN;
+
packet_data.pkt_type = AM65_CPSW_CPPI_PKT_TYPE;
packet_data.dest_tag = priv->port_id;
ret = dma_send(&common->dma_tx, packet, length, &packet_data);
@@ -503,6 +509,9 @@
struct am65_cpsw_priv *priv = dev_get_priv(dev);
struct am65_cpsw_common *common = priv->cpsw_common;
+ if (!common->started)
+ return -ENETDOWN;
+
/* try to receive a new packet */
return dma_receive(&common->dma_rx, (void **)packetp, NULL);
}