The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From e8684db191e4164f3f5f3ad7dec04a6734c25f1c Mon Sep 17 00:00:00 2001

From: Yuiko Oshino yuiko.oshino@microchip.com Date: Wed, 27 Oct 2021 14:23:02 -0400 Subject: [PATCH] net: ethernet: microchip: lan743x: Fix skb allocation failure

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

diff --git a/drivers/net/ethernet/microchip/lan743x_main.c b/drivers/net/ethernet/microchip/lan743x_main.c index c4f32c7e0db1..4d5a5d6595b3 100644 --- a/drivers/net/ethernet/microchip/lan743x_main.c +++ b/drivers/net/ethernet/microchip/lan743x_main.c @@ -1944,7 +1944,8 @@ static void lan743x_rx_update_tail(struct lan743x_rx *rx, int index) index); }

-static int lan743x_rx_init_ring_element(struct lan743x_rx *rx, int index) +static int lan743x_rx_init_ring_element(struct lan743x_rx *rx, int index, + gfp_t gfp) { struct net_device *netdev = rx->adapter->netdev; struct device *dev = &rx->adapter->pdev->dev; @@ -1958,7 +1959,7 @@ static int lan743x_rx_init_ring_element(struct lan743x_rx *rx, int index)

descriptor = &rx->ring_cpu_ptr[index]; buffer_info = &rx->buffer_info[index]; - skb = __netdev_alloc_skb(netdev, buffer_length, GFP_ATOMIC | GFP_DMA); + skb = __netdev_alloc_skb(netdev, buffer_length, gfp); if (!skb) return -ENOMEM; dma_ptr = dma_map_single(dev, skb->data, buffer_length, DMA_FROM_DEVICE); @@ -2120,7 +2121,8 @@ static int lan743x_rx_process_buffer(struct lan743x_rx *rx)

/* save existing skb, allocate new skb and map to dma */ skb = buffer_info->skb; - if (lan743x_rx_init_ring_element(rx, rx->last_head)) { + if (lan743x_rx_init_ring_element(rx, rx->last_head, + GFP_ATOMIC | GFP_DMA)) { /* failed to allocate next skb. * Memory is very low. * Drop this packet and reuse buffer. @@ -2335,13 +2337,16 @@ static int lan743x_rx_ring_init(struct lan743x_rx *rx)

rx->last_head = 0; for (index = 0; index < rx->ring_size; index++) { - ret = lan743x_rx_init_ring_element(rx, index); + ret = lan743x_rx_init_ring_element(rx, index, GFP_KERNEL); if (ret) goto cleanup; } return 0;

cleanup: + netif_warn(rx->adapter, ifup, rx->adapter->netdev, + "Error allocating memory for LAN743x\n"); + lan743x_rx_ring_cleanup(rx); return ret; }