Re: [PATCH net] net: dpaa: always set a valid mode I/F mode
From: Sean Anderson <sean.anderson@linux.dev>
Date: 2026-07-09 23:45:46
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On 7/6/26 08:08, Michael Walle wrote:
Before converting to the phylink interface, the init function would have set the correct mode in the maccfg2.
So for reference, the old logic is
if (iface_speed < SPEED_1000)
tmp |= MACCFG2_NIBBLE_MODE;
else if (iface_speed == SPEED_1000)
tmp |= MACCFG2_BYTE_MODE;
which changes between nibble/byte mode depending on the max link speed
(e.g. phylink_interface_max_speed). Notably, neither is set for 2.5G.
Can you try moving this write to dtsec_mac_config? And check in the RM
whether this is configured based on the interface (in which case we should
remove it from dtsec_link_up) or the link speed. And please also check what
the correct behavior for 2.5G should be.
At one point I had the P-series RMs downloaded, but it appears I've misplaced
them...
--Sean
quoted hunk ↗ jump to hunk
After converting, init will just set 0 as the mode. According to the "QorIQ Data Path Acceleration Architecture (DPAA) Reference Manual", this is a reserved value. In fact, this will prevent the PCS to establish a link to a connected SGMII PHY. In turn, mac_link_up() is never called. Fix it by setting a non-reserved mode; mac_link_up() will then set the correct mode later. Fixes: 5d93cfcf7360 ("net: dpaa: Convert to phylink") Signed-off-by: Michael Walle <mwalle@kernel.org> --- FWIW, I've tested this with a Marvell 88E1112 PHY. drivers/net/ethernet/freescale/fman/fman_dtsec.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)diff --git a/drivers/net/ethernet/freescale/fman/fman_dtsec.c b/drivers/net/ethernet/freescale/fman/fman_dtsec.c index fe35703c509e..566921d3a884 100644 --- a/drivers/net/ethernet/freescale/fman/fman_dtsec.c +++ b/drivers/net/ethernet/freescale/fman/fman_dtsec.c@@ -402,7 +402,10 @@ static int init(struct dtsec_regs __iomem *regs, struct dtsec_cfg *cfg, tmp |= MACCFG1_TX_FLOW; iowrite32be(tmp, ®s->maccfg1); - tmp = 0; + /* write a non-reserved mode, otherwise the PCS won't establish a link + * and .mac_link_up() is never called. + */ + tmp = MACCFG2_NIBBLE_MODE; tmp |= (cfg->preamble_len << MACCFG2_PREAMBLE_LENGTH_SHIFT) & MACCFG2_PREAMBLE_LENGTH_MASK;