Re: [PATCH 0/6] Additional regulator support for the Qualcomm SGMII SerDes PHY

From: Mohd Ayaan Anwar

Date: Fri Jun 26 2026 - 02:14:31 EST


On Mon, Jun 22, 2026 at 04:08:55PM +0200, Loic Poulain wrote:
> Hi,
>
> On Mon, Nov 24, 2025 at 10:26 AM Mohd Ayaan Anwar
> <mohd.anwar@xxxxxxxxxxxxxxxx> wrote:
> >
> > This patch series addresses a SerDes power-up failure observed on the
> > QCS8300 Ride board using the phy-qcom-sgmii-eth driver. The issue occurs
> > because the SerDes PHY requires both L5A and L4A regulators to be
> > enabled during initialization. If either one of them is disabled, the
> > status register does not reset, and the Ethernet interface fails to come
> > up due to a timeout:
> >
> > [ 77.105651] qcom-dwmac-sgmii-phy 8909000.phy: QSERDES_COM_C_READY_STATUS timed-out
> > [ 77.113447] qcom-ethqos 23040000.ethernet eth0: __stmmac_open: Serdes powerup failed
> >
> > Presumably, the issue is not seen on all users of this PHY because both
> > regulators are often shared with other peripherals. However, the power
> > rail schematics for boards using this SerDes PHY show that it is
> > supplied by both L5A (1.2V) and L4A (0.9V) regulators.
> >
> > This series has been tested on the QCS8300 Ride board, and the reported
> > issue was resolved. All Monaco and Lemans derivative boards require this
> > new configuration as they use the same SerDes PHY.
> >
> > Signed-off-by: Mohd Ayaan Anwar <mohd.anwar@xxxxxxxxxxxxxxxx>
>
> This appears to be a real issue, but I haven’t seen a new version of
> the series or any response to the feedback so far. Could you please
> follow up on this?
>

I will shortly send out a v2. I got access to more details about the
hardware, and it has two dedicated regulators which need to be enabled.
The same requirements are there on all Lemans/Monaco-based boards.

Ayaan