Re: [PATCH v16 0/3] eDP/DP Phy vdda realted function

[Mark Brown <broonie@kernel.org>]

[-- Attachment #1: Type: text/plain, Size: 1517 bytes --]

On Thu, Jul 21, 2022 at 12:31:41PM +0200, Johan Hovold wrote:

If you're copying someone into a thread that's not obviously relevant
for them it's good practice to put a note about it at the top of the
mail to reduce the chances that it just gets deleted unread - people get
copies of all sorts of random stuff for not great reasons (like getting
pulled in by checkpatch due to once having done a cleanup) and are often
quicky to delete things.

> This series breaks USB and PCIe for some SC8280XP and SA540P machines
> where the DP PHY regulators are shared with other PHYs whose drivers do
> not request a load.

> Specifically, the hard-coded vdda-phy load of 21.8 mA added by this
> series, causes several RPMh regulators to now be put in low-power mode.

> I found Doug's suggestion to handle situations like this in regulator
> core:
> 
> 	https://lore.kernel.org/all/20180814170617.100087-1-dianders@chromium.org/

> but since that was rejected, how do we deal with this generally?

> In the above thread Doug mentioned adding support for load requests to
> further drivers and Bjorn mentioned working around it by adding
> regulator-system-load properties to DT.

> It seems quite likely that changes like this one affects other systems
> too, and the effects may be hard to debug. So a more general solution
> than playing whack-a-mole using DT would be good to have.

You could add a way to specify constant base loads in DT on either a per
regulator or per consumer basis.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]