net: broadcom: bcm4908_enet: reset DMA rings sw indexes properly

[ Upstream commit ddeacc4f6494e07cbb6f033627926623f3e7a9d0 ]

Resetting software indexes in bcm4908_dma_alloc_buf_descs() is not
enough as it's called during device probe only. Driver resets DMA on
every .ndo_open callback and it's required to reset indexes then.

This fixes inconsistent rings state and stalled traffic after interface
down & up sequence.

Fixes: 4feffeadbcb2 ("net: broadcom: bcm4908enet: add BCM4908 controller driver")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/broadcom/bcm4908_enet.c b/drivers/net/ethernet/broadcom/bcm4908_enet.c
index 65981931a79899fb54754aecee86392ed544a51f..a31984cd0fb7b0c5b1b115a2955d37e4a297e9cd 100644 (file)
--- a/drivers/net/ethernet/broadcom/bcm4908_enet.c
+++ b/drivers/net/ethernet/broadcom/bcm4908_enet.c
@@ -165,9 +165,6 @@ static int bcm4908_dma_alloc_buf_descs(struct bcm4908_enet *enet,
        if (!ring->slots)
                goto err_free_buf_descs;
 
-       ring->read_idx = 0;
-       ring->write_idx = 0;
-
        return 0;
 
 err_free_buf_descs:
@@ -295,6 +292,9 @@ static void bcm4908_enet_dma_ring_init(struct bcm4908_enet *enet,
 
        enet_write(enet, ring->st_ram_block + ENET_DMA_CH_STATE_RAM_BASE_DESC_PTR,
                   (uint32_t)ring->dma_addr);
+
+       ring->read_idx = 0;
+       ring->write_idx = 0;
 }
 
 static void bcm4908_enet_dma_uninit(struct bcm4908_enet *enet)