Re: [PATCH RFC 3/9] net: stmmac: qcom-ethqos: fix RGMII_ID mode to use DLL bypass

From: Andrew Lunn

Date: Thu Jun 11 2026 - 16:57:44 EST


On Fri, Jun 12, 2026 at 12:06:59AM +0530, Mohd Ayaan Anwar wrote:
> When "rgmii-id" is selected the PHY supplies both TX and RX delays, so
> the MAC must not add its own. The driver currently falls through to the
> generic DLL initialisation path which programs it to add a delay.
>
> Power down the DLL and set DDR bypass mode for RGMII_ID, then program
> the IO_MACRO via a new ethqos_rgmii_id_macro_init() helper. Also fix
> ethqos_set_clk_tx_rate() to not double the clock rate in bypass mode at
> 100M/10M, and remove RGMII_ID from the phase-shift suppression in
> ethqos_rgmii_macro_init() since RGMII_ID no longer reaches that path.

I'm curious how this works at the moment? Do no boards make use of
RGMII ID? Are all current boards broken?

Andrew