[BUG] k3-j784s4-evm/phy-cadence-torrent: Shared reset using exclusive API

[Andrew Halaney]

On Wed, Jul 10, 2024 at 10:29:46AM GMT, Siddharth Vadapalli wrote:

<snip>

> 
> No, the resets are correct. Both PCIe1 and USB0 use the same instances
> of SERDES which is SERDES0. I had posted the series for PCIe at:
> https://lore.kernel.org/r/20240529082259.1619695-1-s-vadapalli@ti.com/
> with all 4 Lanes of SERDES0 given to PCIe1. Similarly, Ravi had posted
> the series for USB at:
> https://lore.kernel.org/r/20240507095545.8210-1-r-gunasekaran@ti.com/
> with lane 3 of SERDES0 given to USB0.
> 
> Since both of the series got merged on the same day (14 Jun 2024):
> PCIe series:
> https://lore.kernel.org/r/171826022277.240984.16790260886500529482.b4-ty@ti.com/
> USB series:
> https://lore.kernel.org/r/171826022274.240984.5150753966671933401.b4-ty@ti.com/
> the dependency was unknown when the individual series were posted as
> neither of them was a part of linux-next/ti-k3-dts-next when the other
> one was posted.
> 
> > 
> > Total aside, I think we should put the above dts snippet into one &serdes0 reference
> > for readability sake. I'd post the patch but I'm hoping to get the above answered
> > first in order to clean that up before shuffling things around for readability sake.
> 
> Yes, I agree that both sub-nodes should go into the same referenced
> serdes0 node in k3-j784s4-evm.dts. The reason it didn't happen that way
> to begin with is due to the fact that both series got merged on the same
> day as I pointed out above.
> 
> The fix in this case will be to assign lanes 0 and 1 of SERDES0 to PCIe1
> and lane 3 to USB0 with lane 2 left unused since PCIe doesn't have the
> concept of a x3 link. In such a configuration, the device-tree nodes
> will look like:

Thanks alot for the quick explanation and suggestion!

> 
> &serdes0 {
> 	status = "okay";
> 
> 	serdes0_pcie1_link: phy at 0 {
> 		reg = <0>;
> 		cdns,num-lanes = <2>;
> 		#phy-cells = <0>;
> 		cdns,phy-type = <PHY_TYPE_PCIE>;
> 		resets = <&serdes_wiz0 1>, <&serdes_wiz0 2>;
> 	};
> 
> 	serdes0_usb_link: phy at 3 {
> 		reg = <3>;
> 		cdns,num-lanes = <1>;
> 		#phy-cells = <0>;
> 		cdns,phy-type = <PHY_TYPE_USB3>;
> 		resets = <&serdes_wiz0 4>;
> 	};
> };
> 
> Thank you for pointing out this issue. Please let me know if you plan to
> post the patch with the above fix or you want me to post the patch for it.
> 

I've posted a series (with you CC'ed, just realized I CC'ed Matt instead
of Ravi -- whoops): https://lore.kernel.org/all/20240710-k3-j784s4-evm-serdes0-cleanup-v1-0-03850fe33922@redhat.com/

I'll be on PTO the next few days, so if any changes are required there
do feel free to do them on my behalf if I don't respin by end of today
US-time, otherwise I'll make the changes when I return next week.

Thanks again,
Andrew!