On 8/11/23 11:08, Vladimir Oltean wrote:

Hi Sean,

On Tue, Jun 13, 2023 at 05:27:54PM +0300, Vladimir Oltean wrote:

quoted

quoted

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At first sight you might appear to have a point related to the fact that
PLL register writes are necessary, and thus this whole shebang is necessary.
But this can all be done using PBI commands, with the added benefit that
U-Boot can also use those SERDES networking ports, and not just Linux.
You can use the RCW+PBL specific to your board to inform the SoC that
your platform's refclk 1 is 156 MHz (something which the reset state
machine seems unable to learn, with protocol 0x3333). You don't have to
put that in the device tree. You don't have to push code to any open
source project to expose your platform specific details. Then, just like
in the case of the Lynx 28G driver on LX2160, the SERDES driver could
just treat the PLL configuration as read-only, which would greatly
simplify things and eliminate the need for a clk driver.

Here is an illustrative example (sorry, I don't have a board with the
right refclk on that PLL, to verify all the way):

... snip ...

(which of course complicates the process of building the PBIs...)

Maybe this is the language barrier, but what are you trying to say here?

I said that I don't understand. Can you please clarify what you were
trying to transmit with this comment?

Well, right now I produce my RCWs by generating a second RCW with e.g.
1133 replaced by 3333. But doing this is a more involved change. Just a
minor issue, really. That said, I don't think this is the best approach
moving forward. Much like many other platforms, users should be able to
plug in an SFP module and Linux should configure things appropriately.
An RCW approach requires some kind of configuration tool to swap out the
bootloaders, which isn't as good of a user experience.

--Sean

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