Re: [PATCH v8 2/2] mfd: ac200: Add X-Powers AC200 support

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Unconditional global chip reset in shutdown/remove breaks RTC wake, Wake-on-LAN, and live PHY state.
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commit d8592c963caa9b21487926208ea5815e059be1be
Author: James Hilliard <james.hilliard1@gmail.com>

mfd: ac200: Add X-Powers AC200 support
    
This commit adds support for the X-Powers AC200 mixed-signal companion IC.
It enables the shared input clock, initializes the paged regmap, and asserts
a chip reset during probe, driver removal, and system shutdown.

> diff --git a/drivers/mfd/ac200.c b/drivers/mfd/ac200.c
> new file mode 100644
> index 0000000000000..8445a460ef6c2
> --- /dev/null
> +++ b/drivers/mfd/ac200.c

[ ... ]

> +static void ac200_disable(struct regmap *regmap)
> +{
> +	regmap_write(regmap, AC200_SYS_CONTROL_REG, 0);
> +}

[Severity: High]
Does asserting a global chip reset here wipe the hardware state of all
co-packaged functions, including the RTC and Fast Ethernet PHY?

Since ac200_disable() is unconditionally called by ac200_shutdown() and
ac200_remove(), could this kill the PHY and clear the RTC during system
shutdown, breaking Wake-on-LAN and Wake-on-RTC from power-off states?

Furthermore, because the PHY is enumerated separately on the MDIO bus and
only references this MFD via a phandle, will unbinding the AC200 driver at
runtime (via ac200_remove) forcefully reset the PHY hardware out from under
the active MDIO PHY driver and lead to unpredictable network failures?

[ ... ]

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Sashiko AI review · https://sashiko.dev/#/patchset/20260902-submit-ac200-mfd-v8-0-2aa06720b8ac@gmail.com?part=2