diff options
| author | Vladimir Oltean <vladimir.oltean@nxp.com> | 2023-04-15 20:05:51 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2023-04-17 19:01:19 -0700 |
| commit | 403ffc2c34de5297d007e0e169bf022094d444c2 (patch) | |
| tree | 50c835cd0c7aaad2aedd9a49e5695f55c1e46523 /drivers/net/dsa | |
| parent | a1ca9f8b07d865224a6e4b1c41692f10bd95a311 (diff) | |
| download | lwn-403ffc2c34de5297d007e0e169bf022094d444c2.tar.gz lwn-403ffc2c34de5297d007e0e169bf022094d444c2.zip | |
net: mscc: ocelot: add support for preemptible traffic classes
In order to not transmit (preemptible) frames which will be received by
the link partner as corrupted (because it doesn't support FP), the
hardware requires the driver to program the QSYS_PREEMPTION_CFG_P_QUEUES
register only after the MAC Merge layer becomes active (verification
succeeds, or was disabled).
There are some cases when FP is known (through experimentation) to be
broken. Give priority to FP over cut-through switching, and disable FP
for known broken link modes.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net/dsa')
| -rw-r--r-- | drivers/net/dsa/ocelot/felix_vsc9959.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/net/dsa/ocelot/felix_vsc9959.c b/drivers/net/dsa/ocelot/felix_vsc9959.c index e055b3980ccc..cfb3faeaa5bf 100644 --- a/drivers/net/dsa/ocelot/felix_vsc9959.c +++ b/drivers/net/dsa/ocelot/felix_vsc9959.c @@ -2519,6 +2519,7 @@ static void vsc9959_cut_through_fwd(struct ocelot *ocelot) for (port = 0; port < ocelot->num_phys_ports; port++) { struct ocelot_port *ocelot_port = ocelot->ports[port]; + struct ocelot_mm_state *mm = &ocelot->mm[port]; int min_speed = ocelot_port->speed; unsigned long mask = 0; u32 tmp, val = 0; @@ -2559,10 +2560,12 @@ static void vsc9959_cut_through_fwd(struct ocelot *ocelot) /* Enable cut-through forwarding for all traffic classes that * don't have oversized dropping enabled, since this check is - * bypassed in cut-through mode. + * bypassed in cut-through mode. Also exclude preemptible + * traffic classes, since these would hang the port for some + * reason, if sent as cut-through. */ if (ocelot_port->speed == min_speed) { - val = GENMASK(7, 0); + val = GENMASK(7, 0) & ~mm->active_preemptible_tcs; for (tc = 0; tc < OCELOT_NUM_TC; tc++) if (vsc9959_port_qmaxsdu_get(ocelot, port, tc)) |