Re: [PATCH net v2] net: ti: icssg-prueth: Fix buffer allocation for ICSSG

["MITTAL, HIMANSHU" <h-mittal1@ti.com>]

On 7/15/2025 3:59 PM, Simon Horman wrote:
> On Tue, Jul 15, 2025 at 12:37:45PM +0530, MITTAL, HIMANSHU wrote:
>
> ...
>
>>>> +-----+-----------------------------------------------+
>>>> |     |       SLICE 0       |        SLICE 1          |
>>>> |     +------------+----------+------------+----------+
>>>> |     | Start addr | End addr | Start addr | End addr |
>>>> +-----+------------+----------+------------+----------+
>>>> | EXP | 70024000   | 70028000 | 7002C000   | 70030000 | <-- Overlapping
>>> Thanks for the detailed explanation with these tables.
>>> It is very helpful. I follow both the existing and new mappings
>>> with their help. Except for one thing.
>>>
>>> It's not clear how EXP was set to the values on the line above.
>>> Probably I'm missing something very obvious.
>>> Could you help me out here?
>> The root cause for this issue is that, buffer configuration for Express
>> Frames
>> in function: prueth_fw_offload_buffer_setup() is missing.
>>
>>
>> Details:
>> The driver implements two distinct buffer configuration functions that are
>> invoked
>> based on the driver state and ICSSG firmware:-
>> prueth_fw_offload_buffer_setup()
>> - prueth_emac_buffer_setup()
>>
>> During initialization, the driver creates standard network interfaces
>> (netdevs) and
>> configures buffers via prueth_emac_buffer_setup(). This function properly
>> allocates
>> and configures all required memory regions including:
>> - LI buffers
>> - Express packet buffers
>> - Preemptible packet buffers
>>
>> However, when the driver transitions to an offload mode (switch/HSR/PRP),
>> buffer reconfiguration is handled by prueth_fw_offload_buffer_setup().
>> This function does not reconfigure the buffer regions required for Express
>> packets,
>> leading to incorrect buffer allocation.
> Thanks for your patience, I see that now :)
>
> I'm sorry to drag this out, but I do think it would be useful to add
> information above the lines of the above to the patch description.
Thanks for the feedback, I will add this information and create an 
updated patch.
>>>> | PRE | 70030000   | 70033800 | 70034000   | 70037800 |
>>>> +-----+------------+----------+------------+----------+
>>>>
>>>> +---------------------+----------+----------+
>>>> |                     | SLICE 0  |  SLICE 1 |
>>>> +---------------------+----------+----------+
>>>> | Default Drop Offset | 00000000 | 00000000 |     <-- Field not configured
>>>> +---------------------+----------+----------+
>>> ...