AW: [PATCH] Add SH7720 CPU support

[EXTERNAL B. M. (P. ST-FIR/Eng) <ext...@de...>]

Hi,

I'm back again and reworking the SH7720 patch. Migration to the new INTC
is nearly finished and the kernel boots successfuly.

> The DMA API is in a bit of flux at the moment, we've got to revamp it
> for the driver model and also for dmaengine integration.=20
...
> Yes, the UBC stuff is completely bitrotted.=20
...
> I'm hopeful Roland will get the remaining
> issues sorted out for 2.6.24 or so so we can actually fix up the UBC
> for once.=20

I will wait with this two parts until they are reworked.


>> A small bug was fixed after line 367 rtc-sh.c. The comment already
>> claimed to stop the RTC, but actually it was not done. This is not
>> necessary for all CPUs, but at least for 7720 and 7705.
>>=20
> Looks like an issue with the block version. I suppose we should
> version it explicitly and keep the CPU selections in the Kconfig,
> rather than having the driver turn in to ifdef hell.
>=20

I will put this in a seperate patch.

>> We tried to implement early printk but failed miserably. The
>> scif_sercon_init function was never called.  Any hints?
>>=20
> scif_sercon_init() currently depends on SH-4, and will only be called
> if you boot with earlyprintk=3Dserial, and have
> CONFIG_EARLY_SCIF_CONSOLE set.=20
>=20
> Most platforms do not want any reinit of the ports for debug, we
> generally just want to reuse the bootloader configuration and give the
> kernel an idea of where an initialized port is in order to do the
> early printk.
>=20

I realised, that early_printk relies on SH4 and changed the code to work
on SH3.
The kernel command line was set up properly, too. So I don't have any
clue why it=20
didn't work. I will have a look at this later, but the real scif driver
works, so=20
it's not very important.

> kgdb is being replaced with the unified stub, which is currently in
> -mm. You may want to look at that and see if it works for you. I've
> identified a few problems with it that I've hacked some patches up
> for, but I've not had the time to finish those up and get them to
> Andrew yet. I'll try and do that if you're interested in this.

I will try -mm when I've time, but I'm glad to hear real kgdb support is
on ist way

>=20
>> Ethernet NFS performance is pretty bad (about 500 kB/s). I have not
>> done any research on this yet.
>>=20
> This is pretty normal when the sense selection on the IRQ is wrong.
> It's especially common for edge-triggered smc91x chips when the
> IPR/INTC2 code does level sensing. The INTC stuff from Magnus
> provides the proper hooks for getting all of this tidied up and
> hooked up for your CPU, I'd suggest looking at that first.

I have a smsc9115 (smc911x) which only handles level irqs. The INTC code

seems to be a much cleaner solution than the old one. I already migrated
the IPR=20
Interrupts and will take a closer look at the sens selection tomorrow.

Regards

Markus