gianfar: Fix P1010 config regression (SQ polling)
The P1010 device tree restricts the number of
supported interrupt groups to 1, although the eth
controller can support 2 interrupt groups and the
driver assumes the Multi-Group mode ("fsl,etsec2" model).
So, in this case the assumption that the Multi-Group
mode (MQ_MG_MODE) devices always support 2 interrupt
groups is false. To fix this, a check for the actual
number of interrupt groups enabled in the board's
device tree has been added in gfar_probe for the
"fsl,etsec2" devices.
Without this fix, P1010 based boards claim support for
2 Tx queues to the net stack but only one is actually
allocated, leading to NULL access in xmit. This issue
was introduced by enabling Single-Queue polling for
the P1010 devices.
(71ff9e3 gianfar: Use Single-Queue polling for
"fsl,etsec2")
Fixes: 71ff9e3df7e1c5d3293af6b595309124e8c97412
Signed-off-by: Claudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c
index 6e12f93..9125d9a 100644
--- a/drivers/net/ethernet/freescale/gianfar.c
+++ b/drivers/net/ethernet/freescale/gianfar.c
@@ -754,9 +754,19 @@
num_tx_qs = 1;
num_rx_qs = 1;
} else { /* MQ_MG_MODE */
+ /* get the actual number of supported groups */
+ unsigned int num_grps = of_get_available_child_count(np);
+
+ if (num_grps == 0 || num_grps > MAXGROUPS) {
+ dev_err(&ofdev->dev, "Invalid # of int groups(%d)\n",
+ num_grps);
+ pr_err("Cannot do alloc_etherdev, aborting\n");
+ return -EINVAL;
+ }
+
if (poll_mode == GFAR_SQ_POLLING) {
- num_tx_qs = 2; /* one txq per int group */
- num_rx_qs = 2; /* one rxq per int group */
+ num_tx_qs = num_grps; /* one txq per int group */
+ num_rx_qs = num_grps; /* one rxq per int group */
} else { /* GFAR_MQ_POLLING */
num_tx_qs = tx_queues ? *tx_queues : 1;
num_rx_qs = rx_queues ? *rx_queues : 1;