From: Arınç ÜNAL arinc.unal@arinc9.com
[ Upstream commit 120a56b01beed51ab5956a734adcfd2760307107 ]
On mt753x_cpu_port_enable() there's code that enables flooding for the CPU port only. Since mt753x_cpu_port_enable() runs twice when both CPU ports are enabled, port 6 becomes the only port to forward the frames to. But port 5 is the active port, so no frames received from the user ports will be forwarded to port 5 which breaks network connectivity.
Every bit of the BC_FFP, UNM_FFP, and UNU_FFP bits represents a port. Fix this issue by setting the bit that corresponds to the CPU port without overwriting the other bits.
Clear the bits beforehand only for the MT7531 switch. According to the documents MT7621 Giga Switch Programming Guide v0.3 and MT7531 Reference Manual for Development Board v1.0, after reset, the BC_FFP, UNM_FFP, and UNU_FFP bits are set to 1 for MT7531, 0 for MT7530.
The commit 5e5502e012b8 ("net: dsa: mt7530: fix roaming from DSA user ports") silently changed the method to set the bits on the MT7530_MFC. Instead of clearing the relevant bits before mt7530_cpu_port_enable() which runs under a for loop, the commit started doing it on mt7530_cpu_port_enable().
Back then, this didn't really matter as only a single CPU port could be used since the CPU port number was hardcoded. The driver was later changed with commit 1f9a6abecf53 ("net: dsa: mt7530: get cpu-port via dp->cpu_dp instead of constant") to retrieve the CPU port via dp->cpu_dp. With that, this silent change became an issue for when using multiple CPU ports.
Fixes: 5e5502e012b8 ("net: dsa: mt7530: fix roaming from DSA user ports") Signed-off-by: Arınç ÜNAL arinc.unal@arinc9.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/dsa/mt7530.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c index 4e63f14c42228..855220c5ce339 100644 --- a/drivers/net/dsa/mt7530.c +++ b/drivers/net/dsa/mt7530.c @@ -1015,9 +1015,9 @@ mt753x_cpu_port_enable(struct dsa_switch *ds, int port) mt7530_write(priv, MT7530_PVC_P(port), PORT_SPEC_TAG);
- /* Disable flooding by default */ - mt7530_rmw(priv, MT7530_MFC, BC_FFP_MASK | UNM_FFP_MASK | UNU_FFP_MASK, - BC_FFP(BIT(port)) | UNM_FFP(BIT(port)) | UNU_FFP(BIT(port))); + /* Enable flooding on the CPU port */ + mt7530_set(priv, MT7530_MFC, BC_FFP(BIT(port)) | UNM_FFP(BIT(port)) | + UNU_FFP(BIT(port)));
/* Set CPU port number */ if (priv->id == ID_MT7621) @@ -2331,6 +2331,10 @@ mt7531_setup_common(struct dsa_switch *ds) /* Enable and reset MIB counters */ mt7530_mib_reset(ds);
+ /* Disable flooding on all ports */ + mt7530_clear(priv, MT7530_MFC, BC_FFP_MASK | UNM_FFP_MASK | + UNU_FFP_MASK); + for (i = 0; i < MT7530_NUM_PORTS; i++) { /* Disable forwarding by default on all ports */ mt7530_rmw(priv, MT7530_PCR_P(i), PCR_MATRIX_MASK,