Hi Serge,

On Mon, May 6, 2019 at 4:39 PM Serge Semin [off-list ref] wrote:
[...]

quoted

the changes in patch 1 are looking good to me (except that I would use
phy_modify_paged instead of open-coding it, functionally it's
identical with what you have already)

Nah, this isn't going to work since the config register is placed on an extension
page. So in order to reach the register first I needed to enable a standard page,
then select an extended page, then modify the register bits.

I'm probably missing something here. my understanding about
phy_modify_paged is that it is equal to:
- select extension page
- read register
- calculate the new register value
- write register
- restore the original extension page

if phy_modify_paged doesn't work for your use-case then ignore my comment.

[...]

quoted

quoted

(Martin, I also Cc'ed you in this discussion, so if you have anything to
say in this matter, please don't hesitate to comment.)

Amlogic boards, such as the Hardkernel Odroid-C1 and Odroid-C2 as well
as the Khadas VIM2 use a "RTL8211F" RGMII PHY. I don't know whether
there are multiple versions of this PHY. all RTL8211F I have seen so
far did behave exactly the same.

I also don't know whether the RX delay is configurable (by pin
strapping or some register) on RTL8211F PHYs because I don't have
access to the datasheet.


Martin

Ok. Thanks for the comments. I am sure the RX-delay is configurable at list
via external RXD pin strapping at the chip powering up procedure. The only
problem with a way of software to change the setting.

I don't think there is going to be anyone revealing that realtek black boxed
registers layout anytime soon. So as I see it it's better to leave the
rtl8211f-part as is for now.

with the RTL8211F I was not sure whether interrupt support was
implemented correctly in the mainline driver.
I asked Realtek for more details:
initially they declined to send me a datasheet and referred me to my
"partner contact" (which I don't have because I'm doing this in my
spare time).
I explained that I am trying to improve the Linux driver for this PHY.
They gave me the relevant bits (about interrupt support) from the
datasheet (I never got the full datasheet though).

if you don't want to touch the RTL8211F part for now then I'm fine
with that as well


Regards
Martin