| From foo@baz Thu Jun 8 08:58:26 CEST 2017 |
| From: Niklas Cassel <niklas.cassel@axis.com> |
| Date: Tue, 6 Jun 2017 09:25:00 +0200 |
| Subject: net: stmmac: fix completely hung TX when using TSO |
| |
| 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(-) |
| |
| --- 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; |
