Re: [PATCH] arm64: dts: qcom: sc7280: Update SNPS Phy params for SC7280

From: Krishna Kurapati PSSNV
Date: Thu Sep 29 2022 - 05:46:05 EST



On 9/29/2022 2:44 PM, Krzysztof Kozlowski wrote:
On 29/09/2022 11:02, Dmitry Baryshkov wrote:
On Thu, 29 Sept 2022 at 11:54, Krishna Kurapati PSSNV
<quic_kriskura@xxxxxxxxxxx> wrote:


On 9/29/2022 1:29 PM, Dmitry Baryshkov wrote:
On Thu, 29 Sept 2022 at 10:14, Krishna Kurapati
<quic_kriskura@xxxxxxxxxxx> wrote:

Override the SNPS Phy tuning parameters for SC7280 devices. These
values are common for both trogdor and herobrine variants.

They are common for trogdor and herobrine, but should these parameters
be a default? In other words, a random new device based on sc7280
would more likely use these overrides or the hardware defaults?

Hi Dmitry,

Currently there are only two platforms, so I made these changes on
common dtsi. If a new platform comes (mostly it won't) we can override
them in platform specific file is what I thought.

Hi Dmitry, Krzysztof,

This is not how it usually works. The 'sc7280.dtsi' is not a 'common
dtsi' for trogdor and herobrine. It describes the SoC.
Thus in my opinion if these overrides should be a default to all
sc7280 platforms, this patch is fine. If these overrides are
applicable only to the two mentioned platforms, they should go to
respective platform-specific DT files.

Dmitry's conclusion is correct here. The true question is whether these
are properties of the SoC itself (so do not depend on the board or board
layout) or these depend on design of board.

Best regards,
Krzysztof

Thanks for the info. These parameters are per-board and not common to SoC. I sent one patch previously for IDP platform [1]. I will let that get merged and I will send a v2 of this patch adding parameters only for herobrine platform.

[1] : https://patchwork.kernel.org/project/linux-usb/patch/1662480933-12326-4-git-send-email-quic_kriskura@xxxxxxxxxxx/

Thanks,
Krishna,