net: stmmac: fix completely hung TX when using TSO
[ Upstream commit 426849e6611f2092553f8d53372ae310818a6292 ]
stmmac_tso_allocator can fail to set the Last Descriptor bit
on a descriptor that actually was the last descriptor.
This happens when the buffer of the last descriptor ends
up having a size of exactly TSO_MAX_BUFF_SIZE.
When the IP eventually reaches the next last descriptor,
which actually has the bit set, the DMA will hang.
When the DMA hangs, we get a tx timeout, however,
since stmmac does not do a complete reset of the IP
in stmmac_tx_timeout, we end up in a state with
completely hung TX.
Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
Acked-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Acked-by: Alexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index b2893fb..ef6bff8 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1953,7 +1953,7 @@
priv->hw->desc->prepare_tso_tx_desc(desc, 0, buff_size,
0, 1,
- (last_segment) && (buff_size < TSO_MAX_BUFF_SIZE),
+ (last_segment) && (tmp_len <= TSO_MAX_BUFF_SIZE),
0, 0);
tmp_len -= TSO_MAX_BUFF_SIZE;