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

[MITTAL, HIMANSHU]

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
> > > > +---------------------+----------+----------+
> > > ...