From: Vladimir Oltean vladimir.oltean@nxp.com
[ Upstream commit 601e984f23abcaa7cf3eb078c13de4db3cf6a4f0 ]
Tail dropping is enabled for a port when:
1. A source port consumes more packet buffers than the watermark encoded in SYS:PORT:ATOP_CFG.ATOP.
AND
2. Total memory use exceeds the consumption watermark encoded in SYS:PAUSE_CFG:ATOP_TOT_CFG.
The unit of these watermarks is a 60 byte memory cell. That unit is programmed properly into ATOP_TOT_CFG, but not into ATOP. Actually when written into ATOP, it would get truncated and wrap around.
Fixes: a556c76adc05 ("net: mscc: Add initial Ocelot switch support") Signed-off-by: Vladimir Oltean vladimir.oltean@nxp.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/mscc/ocelot.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c index 1438839e3f6ea..61bbb7a090042 100644 --- a/drivers/net/ethernet/mscc/ocelot.c +++ b/drivers/net/ethernet/mscc/ocelot.c @@ -2001,7 +2001,7 @@ void ocelot_port_set_maxlen(struct ocelot *ocelot, int port, size_t sdu) struct ocelot_port *ocelot_port = ocelot->ports[port]; int maxlen = sdu + ETH_HLEN + ETH_FCS_LEN; int pause_start, pause_stop; - int atop_wm; + int atop, atop_tot;
if (port == ocelot->npi) { maxlen += OCELOT_TAG_LEN; @@ -2022,12 +2022,12 @@ void ocelot_port_set_maxlen(struct ocelot *ocelot, int port, size_t sdu) ocelot_rmw_rix(ocelot, SYS_PAUSE_CFG_PAUSE_STOP(pause_stop), SYS_PAUSE_CFG_PAUSE_STOP_M, SYS_PAUSE_CFG, port);
- /* Tail dropping watermark */ - atop_wm = (ocelot->shared_queue_sz - 9 * maxlen) / + /* Tail dropping watermarks */ + atop_tot = (ocelot->shared_queue_sz - 9 * maxlen) / OCELOT_BUFFER_CELL_SZ; - ocelot_write_rix(ocelot, ocelot->ops->wm_enc(9 * maxlen), - SYS_ATOP, port); - ocelot_write(ocelot, ocelot->ops->wm_enc(atop_wm), SYS_ATOP_TOT_CFG); + atop = (9 * maxlen) / OCELOT_BUFFER_CELL_SZ; + ocelot_write_rix(ocelot, ocelot->ops->wm_enc(atop), SYS_ATOP, port); + ocelot_write(ocelot, ocelot->ops->wm_enc(atop_tot), SYS_ATOP_TOT_CFG); } EXPORT_SYMBOL(ocelot_port_set_maxlen);