On Fri, Oct 1, 2021 at 6:04 PM Dmitry Baryshkov
[off-list ref] wrote:

On 28/09/2021 04:13, Saravana Kannan wrote:

quoted

On Mon, Sep 27, 2021 at 5:56 PM Dmitry Baryshkov

<snip>

quoted

quoted

After doing the analysis, I can confirm that I was too quick regarding
the mdss links preventing it from being probed. Sorry about that.

It all went up to the DP phy having a link with usb-c-connector. I was
running the kernel 5.15-rc1, so your tcpm fix is already present.
However my colleague has disabled the tcpm device (which I did not
notice). So the driver did not call fw_devlink_purge_absent_suppliers().
The devlink still exists:

Let me take a closer look at this before the end of this week. Can you
point me to the exact DT changes that were made that's causing this
issue? It should help me debug the issue. I have a guess on what the
issue might be.

Here is the kernel source:
https://git.linaro.org/people/bryan.odonoghue/kernel.git/log/?h=5.15-rc1-camss-v2

The change that causes PHY driver to silently stop probing, causing an
avalanche of devices not being probed:

https://git.linaro.org/people/bryan.odonoghue/kernel.git/commit/?h=5.15-rc1-camss-v2&id=d0bf3fc47c132968c302965154eeb5c88007fa73

Sorry, I haven't had a chance to look into this yet, but I still have
a strong hunch that this is related to how of_device_is_available()
doesn't recurse up till the root to check if a node is disabled (if a
parent is disabled, the child should also be considered disabled). And
I think patch series should help your case due to a side effect (it
wasn't meant as a fix for your issue). Can you give it a shot?

https://lore.kernel.org/lkml/20210929000735.585237-1-saravanak@google.com/ (local)

-Saravana