On 2025/7/3 04:23, Krzysztof Kozlowski wrote:
EXTERNAL EMAIL
On 30/06/2025 17:30, Hans Zhang wrote:
On 2025/6/30 19:14, Krzysztof Kozlowski wrote:
EXTERNAL EMAIL
On 30/06/2025 10:29, Hans Zhang wrote:
+
+ num-lanes:
+ maximum: 8
+
+ ranges:
+ maxItems: 3
+
+ msi-map:
+ maxItems: 1
+
+ vendor-id:
+ const: 0x1f6c
Why? This is implied by compatible.
Because when we designed the SOC RTL, it was not set to the vendor id
and device id of our company. We are members of PCI-SIG. So we need to
set the vendor id and device id in the Root Port driver. Otherwise, the
output of lspci will be displayed incorrectly.
Please read carefully. Previous discussions were also pointlessly
ping-ponging on irrelevant arguments. Did I suggest you do not have to
set it in root port driver? No. If this is const here, this is implied
by compatible and completely redundant, because your driver knows this
value already. It already has all the information to deduce this value
from the compatible.
Dear Krzysztof,
Thank you very much for your reply.
These two attributes are also in the following document. Is this place
out of date?
Documentation/devicetree/bindings/pci/ti,j721e-pci-host.yaml
I would need to spend time to investigate that and I choose to do other
things instead. I am recently very grumpy on arguments "I found this
somewhere else". I found bugs somewhere else, so am I okay to introduce
them?
Dear Krzysztof,
Thank you very much for your reply.
No, no, no. You misunderstood me. I didn't mean to say this because we
don't study dt-binding doc every day. So we can only refer to the
practices of other SOC manufacturers. If it's incorrect, we will
definitely listen to your opinion. Here, I'm just explaining the origin
of what I did.
Anyway, I have solved this problem by following your method and using
compatible.
We initially used the logic of Cadence common driver as follows:
drivers/pci/controller/cadence/pcie-cadence-host.c
of_property_read_u32(np, "vendor-id", &rc->vendor_id);
of_property_read_u32(np, "device-id", &rc->device_id);
So, can the code in Cadence be deleted?
Don't know. If this is ABI, then not.
According to my understanding, this is not ABI.
Best regards,
Hans
Best regards,
Krzysztof
