Re: [PATCH net v2] net: phy: realtek: Reset after clock enable

[Andrew Lunn]

On Thu, Jul 24, 2025 at 04:39:42PM +0200, Sebastian Reichel wrote:
> On Radxa ROCK 4D boards we are seeing some issues with PHY detection and
> stability (e.g. link loss or not capable of transceiving packages) after
> new board revisions switched from a dedicated crystal to providing the
> 25 MHz PHY input clock from the SoC instead.
> 
> This board is using a RTL8211F PHY, which is connected to an always-on
> regulator. Unfortunately the datasheet does not explicitly mention the
> power-up sequence regarding the clock, but it seems to assume that the
> clock is always-on (i.e. dedicated crystal).
> 
> By doing an explicit reset after enabling the clock, the issue on the
> boards could no longer be observed.
> 
> Note, that the RK3576 SoC used by the ROCK 4D board does not yet
> support system level PM, so the resume path has not been tested.
> 
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 7300c9b574cc ("net: phy: realtek: Add optional external PHY clock")
> Signed-off-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>

Reviewed-by: Andrew Lunn <andrew@xxxxxxx>

    Andrew