Re: [PATCH net-next v2 2/2] net: phy: qcom: qca808x: Add regulator management

From: Mohd Ayaan Anwar

Date: Thu Oct 15 2026 - 13:08:14 EST


On Thu, Oct 15, 2026 at 06:27:01PM +0200, Andrew Lunn wrote:
> On Thu, Oct 15, 2026 at 11:01:43AM -0500, Alex Elder wrote:
> > On 10/15/26 10:40 AM, Lorenzo Bianconi wrote:
> > > > + if (count)
> > > > + fsleep(phydev->mdio.reset_assert_delay);
> > > nit: should we check reset_assert_delay field is actually set?
> >
> > Are you saying there should be an alternative delay used
> > if it is not set? Do you have a suggestion for what to
> > use in that case?
>
> Does the binding require the value is set?
>
> What happens it if is 0? I think fsleep() is happy to delay for 0 uS,
> but does the hardware still work? Does the datasheet say anything
> about power on delays?
>

I was going to share a text version of the power-up diagram given in
this PHY's datasheet. This might help.

Power-Up Sequence

1. DVDD asserted
|
|<-------- 10 ms -------->| (required for external power)
|
2. DVDD18 / AVDD18 asserted

3. VDD1P25 asserted
|
|<-------- 0.2 ms ------->| (required for LDO to settle)
|
4. VDD_LDO asserted

5. AVDD asserted
|
|<--------- 2 ms -------->| (required for XTL to oscillate)
|
6. Crystal 50 MHz starts oscillating

7. PAD reset deasserted
|
|<------- 10 ms --------->| (deglitch time)


So, maybe just fsleep(22200) or something a bit higher?

Ayaan