[4.9,011/119] net: stmmac: fix completely hung TX when using TSO
diff mbox series

Message ID 20170612152557.193882097@linuxfoundation.org
State New, archived
Headers show
  • 4.9.32-stable review
Related show

Commit Message

Greg Kroah-Hartman June 12, 2017, 3:24 p.m. UTC
4.9-stable review patch.  If anyone has any objections, please let me know.


From: Niklas Cassel <niklas.cassel@axis.com>

[ 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>
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff mbox series

--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1953,7 +1953,7 @@  static void stmmac_tso_allocator(struct
 		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;