[PATCH v3 net 1/2] net: dsa: mt7530: fix corrupt frames using trgmii on 40 MHz XTAL MT7621

[PATCH v3 net 1/2] net: dsa: mt7530: fix corrupt frames using trgmii on 40 MHz XTAL MT7621

[arinc9.unal]

From: Arınç ÜNAL <arinc.unal@arinc9.com>

The multi-chip module MT7530 switch with a 40 MHz oscillator on the
MT7621AT, MT7621DAT, and MT7621ST SoCs forwards corrupt frames using
trgmii.

This is caused by the assumption that MT7621 SoCs have got 150 MHz PLL,
hence using the ncpo1 value, 0x0780.

My testing shows this value works on Unielec U7621-06, Bartel's testing
shows it won't work on Hi-Link HLK-MT7621A and Netgear WAC104. All devices
tested have got 40 MHz oscillators.

Using the value for 125 MHz PLL, 0x0640, works on all boards at hand. The
definitions for 125 MHz PLL exist on the Banana Pi BPI-R2 BSP source code
whilst 150 MHz PLL don't.

Forwarding frames using trgmii on the MCM MT7530 switch with a 25 MHz
oscillator on the said MT7621 SoCs works fine because the ncpo1 value
defined for it is for 125 MHz PLL.

Change the 150 MHz PLL comment to 125 MHz PLL, and use the 125 MHz PLL
ncpo1 values for both oscillator frequencies.

Link: https://github.com/BPI-SINOVOIP/BPI-R2-bsp/blob/81d24bbce7d99524d0771a8bdb2d6663e4eb4faa/u-boot-mt/drivers/net/rt2880_eth.c#L2195
Fixes: 7ef6f6f8d237 ("net: dsa: mt7530: Add MT7621 TRGMII mode support")
Tested-by: Bartel Eerdekens <bartel.eerdekens@constell8.be>
Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
---

v3: Remove my tested-by tag as Florian pointed out it's implied with my
signed-off-by tag. Add Florian's reviewed-by tag.

---
 drivers/net/dsa/mt7530.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index c680873819b0..7d9f9563dbda 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -426,9 +426,9 @@ mt7530_pad_clk_setup(struct dsa_switch *ds, phy_interface_t interface)
 		else
 			ssc_delta = 0x87;
 		if (priv->id == ID_MT7621) {
-			/* PLL frequency: 150MHz: 1.2GBit */
+			/* PLL frequency: 125MHz: 1.0GBit */
 			if (xtal == HWTRAP_XTAL_40MHZ)
-				ncpo1 = 0x0780;
+				ncpo1 = 0x0640;
 			if (xtal == HWTRAP_XTAL_25MHZ)
 				ncpo1 = 0x0a00;
 		} else { /* PLL frequency: 250MHz: 2.0Gbit */
-- 
2.39.2

[PATCH v3 net 2/2] net: dsa: mt7530: fix network connectivity with multiple CPU ports

[arinc9.unal]

From: Arınç ÜNAL <arinc.unal@arinc9.com>

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>
---

v3: Remove my tested-by tag as Florian pointed out it's implied with my
signed-off-by tag.

v2: Add the fixes tag and information about the commit that caused this
issue.

---
 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 7d9f9563dbda..9bc54e1348cb 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -1002,9 +1002,9 @@ 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)
@@ -2367,6 +2367,10 @@ 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,
-- 
2.39.2

Re: [PATCH v3 net 1/2] net: dsa: mt7530: fix corrupt frames using trgmii on 40 MHz XTAL MT7621

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net.git (main)
by David S. Miller <davem@davemloft.net>:

On Wed,  3 May 2023 00:09:46 +0300 you wrote:
> From: Arınç ÜNAL <arinc.unal@arinc9.com>
> 
> The multi-chip module MT7530 switch with a 40 MHz oscillator on the
> MT7621AT, MT7621DAT, and MT7621ST SoCs forwards corrupt frames using
> trgmii.
> 
> This is caused by the assumption that MT7621 SoCs have got 150 MHz PLL,
> hence using the ncpo1 value, 0x0780.
> 
> [...]

Here is the summary with links:
  - [v3,net,1/2] net: dsa: mt7530: fix corrupt frames using trgmii on 40 MHz XTAL MT7621
    https://git.kernel.org/netdev/net/c/37c218d8021e
  - [v3,net,2/2] net: dsa: mt7530: fix network connectivity with multiple CPU ports
    https://git.kernel.org/netdev/net/c/120a56b01bee

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html