Re: [RFC v4 17/25] powerpc, fbdev: Use arch_nvram_ops methods instead of nvram_read_byte() and nvram_write_byte()

Finn Thain
2015-09-18T08:18:10Z

Hi Ben,

On Thu, 16 Jul 2015, I wrote:

> On Wed, 15 Jul 2015, I wrote:
>
> > On Tue, 14 Jul 2015, Benjamin Herrenschmidt wrote:
> >
> > > Maybe we should have a dedicated accessor for "mac_xpram" ...
> >
> ...
>
> The arch_nvram_ops methods don't deal with structures like partitions ...

Instead of the accessor you suggested, perhaps it would be better to add a
method like arch_nvram_ops.get_partition, to replace the
pmac_get_partition() exported function?

The call sites for pmac_get_partition() are in the implementation of the
IOC_NVRAM_GET_OFFSET ioctl that's used with /dev/nvram, and in
pmac_xpram_read(). pmac_xpram_write() has no caller and could be removed.

But this doesn't have much to do with linux-fbdev. I think the old
NV_CMODE/NV_VMODE issues*, which this patch avoids, are irrelevant to the
problem of nvram module re-use, which is the aim of this patch series.

But if those issues really are relevant then we should move the discussion
to the revised patch, that is, [RFC v6 16/25] powerpc, fbdev: Use NV_CMODE
and NV_VMODE only when CONFIG_PPC32 and CONFIG_PPC_PMAC and CONFIG_NVRAM.

(There was no response to any patch in RFC v6 from any PowerPC
maintainers, which is why I've revived this thread.)

* https://lists.ozlabs.org/pipermail/linuxppc-dev/2001-November/012662.html

--