[PATCH 5.4 3/9] net: ethernet: microchip: lan743x: Fix skb allocation failure

Greg Kroah-Hartman
2021-11-04T14:16:47Z

From: Yuiko Oshino <yuiko.oshino@microchip.com>

commit e8684db191e4164f3f5f3ad7dec04a6734c25f1c upstream.

The driver allocates skb during ndo_open with GFP_ATOMIC which has high chance of failure when there are multiple instances.
GFP_KERNEL is enough while open and use GFP_ATOMIC only from interrupt context.

Fixes: 23f0703c125b ("lan743x: Add main source files for new lan743x driver")
Signed-off-by: Yuiko Oshino <yuiko.oshino@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/net/ethernet/microchip/lan743x_main.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

--- a/drivers/net/ethernet/microchip/lan743x_main.c
+++ b/drivers/net/ethernet/microchip/lan743x_main.c
@@ -1898,13 +1898,13 @@ static int lan743x_rx_next_index(struct
return ((++index) % rx->ring_size);
}

-static struct sk_buff *lan743x_rx_allocate_skb(struct lan743x_rx *rx)
+static struct sk_buff *lan743x_rx_allocate_skb(struct lan743x_rx *rx, gfp_t gfp)
{
int length = 0;

length = (LAN743X_MAX_FRAME_SIZE + ETH_HLEN + 4 + RX_HEAD_PADDING);
return __netdev_alloc_skb(rx->adapter->netdev,
- length, GFP_ATOMIC | GFP_DMA);
+ length, gfp);
}

static void lan743x_rx_update_tail(struct lan743x_rx *rx, int index)
@@ -2077,7 +2077,8 @@ static int lan743x_rx_process_packet(str
struct sk_buff *new_skb = NULL;
int packet_length;

- new_skb = lan743x_rx_allocate_skb(rx);
+ new_skb = lan743x_rx_allocate_skb(rx,
+ GFP_ATOMIC | GFP_DMA);
if (!new_skb) {
/* failed to allocate next skb.
* Memory is very low.
@@ -2314,7 +2315,8 @@ static int lan743x_rx_ring_init(struct l

rx->last_head = 0;
for (index = 0; index < rx->ring_size; index++) {
- struct sk_buff *new_skb = lan743x_rx_allocate_skb(rx);
+ struct sk_buff *new_skb = lan743x_rx_allocate_skb(rx,
+ GFP_KERNEL);

ret = lan743x_rx_init_ring_element(rx, index, new_skb);
if (ret)