This is a note to let you know that I've just added the patch titled
net: dsa: mt7530: fix corrupt frames using trgmii on 40 MHz XTAL MT7621
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-dsa-mt7530-fix-corrupt-frames-using-trgmii-on-40.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 1671499efb97ce4d39c7ad479c7f369fa56d9477
Author: Arınç ÜNAL <arinc.unal@xxxxxxxxxx>
Date: Wed May 3 00:09:46 2023 +0300
net: dsa: mt7530: fix corrupt frames using trgmii on 40 MHz XTAL MT7621
[ Upstream commit 37c218d8021e36e226add4bab93d071d30fe0704 ]
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@xxxxxxxxxxxx>
Signed-off-by: Arınç ÜNAL <arinc.unal@xxxxxxxxxx>
Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index dfea2ab0c297f..e7a551570cf3c 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -441,9 +441,9 @@ 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 */
