[PATCH]Move QRANK_DIMM_SUPPORT to Kconfig

[Patrick Georgi]

Hi,
see patch. It might be possible to find a better place to this variable
(are "qrank dimms" really a per-board thing?), but for now this should
provide absolutely equivalent to the romstage.c defines.

Move QRANK_DIMM_SUPPORT to Kconfig, removing it from romstage.c

Signed-off-by: Patrick Georgi

[Peter Stuge]

Patrick Georgi wrote:
> (are "qrank dimms" really a per-board thing?)

Which boards do not have the variable set?

//Peter

[Patrick Georgi]

Am 05.11.2010 19:20, schrieb Peter Stuge:
> Patrick Georgi wrote:
> > (are "qrank dimms" really a per-board thing?)
>
> Which boards do not have the variable set?

About 30, I think. I only did a grep .. | wc -l comparison:

$ grep NORTHBRIDGE_AMD_AMDK8 src/mainboard/*/*/Kconfig |wc -l
86

So 86 boards are eligible for that option.

$ svn st |grep romstage.c |wc -l
63

63 boards have that option dropped (the patch is the only change in that
tree).

So there are 23 boards that do not set it.

Patrick

[Scott Duplichan]

-----Original Message-----
From: [e-mail] [mailto:[e-mail]] On Behalf Of Peter Stuge
Sent: Friday, November 05, 2010 01:21 PM
To: [e-mail]
Subject: Re: [coreboot] [PATCH]Move QRANK_DIMM_SUPPORT to Kconfig

]Patrick Georgi wrote:
]> (are "qrank dimms" really a per-board thing?)
]
]Which boards do not have the variable set?

I am no quad rank dimm expert, but I think few boards support them. One is Serengeti
Cheetah. I remember asking why one processor socket has 4 dimm slots and another 8.
I was told it was for quad rank dimm testing. The chip selects for two normal dimm sockets
are combined and routed to a quad rank socket, if I remember correctly. I don't even
have any quad ranked dimms to test with. I think they are rare.

Thanks,
Scott

]//Peter

[Ward Vandewege]

On Fri, Nov 05, 2010 at 01:28:59PM -0500, Scott Duplichan wrote:
> I am no quad rank dimm expert, but I think few boards support them. One is Serengeti
> Cheetah. I remember asking why one processor socket has 4 dimm slots and another 8.
> I was told it was for quad rank dimm testing. The chip selects for two normal dimm sockets
> are combined and routed to a quad rank socket, if I remember correctly. I don't even
> have any quad ranked dimms to test with. I think they are rare.

Actually, they are not *that* rare, since they are readily available:

http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&DEPA=0&Ord...

Thanks,
Ward.

[Scott Duplichan]

-----Original Message-----
From: Ward Vandewege [mailto:[e-mail]] 
Sent: Friday, November 05, 2010 01:42 PM
To: Scott Duplichan
Cc: 'Peter Stuge'; [e-mail]
Subject: Re: [coreboot] [PATCH]Move QRANK_DIMM_SUPPORT to Kconfig

]On Fri, Nov 05, 2010 at 01:28:59PM -0500, Scott Duplichan wrote:
]> I am no quad rank dimm expert, but I think few boards support them. One is Serengeti
]> Cheetah. I remember asking why one processor socket has 4 dimm slots and another 8.
]> I was told it was for quad rank dimm testing. The chip selects for two normal dimm sockets
]> are combined and routed to a quad rank socket, if I remember correctly. I don't even
]> have any quad ranked dimms to test with. I think they are rare.
]
]Actually, they are not *that* rare, since they are readily available:
]
]  ]http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&DEPA=0&Ord...

Sure enough. And not a bad price (per MB), either. Thanks for pointing them out.

Though I would question the maturity of coreboot support for registered
DDR3 in general, and specifically for 1333 speed or quad rank. I believe
these were perfected internally at AMD only recently. How well has coreboot
been tested with various speeds of registered DDR3? There is a lot more
complexity in the memory init code when registered DIMMs of any rank count
are used. And there is still the question of what boards supported by coreboot
really have hardware support for quadrank. I would hate to mislead someone
into buying a system loaded with registered memory with the idea of running
coreboot, unless it is known to work.

Thanks,
Scott

]-- 
]Ward Vandewege 
]Free Software Foundation - Senior Systems Administrator

[Patrick Georgi]

Am 05.11.2010 19:58, schrieb Scott Duplichan:
> really have hardware support for quadrank. I would hate to mislead someone
> into buying a system loaded with registered memory with the idea of running
> coreboot, unless it is known to work.

I think (and hope) that I didn't mark any board as quad rank capable
that wasn't marked that way before, but I can't tell if the original
options are set correctly.

In this regard, the tree with this patch is as good as without.

Patrick

[Myles Watson]

> Am 05.11.2010 19:58, schrieb Scott Duplichan:
> > really have hardware support for quadrank. I would hate to mislead
>
> someone
> > into buying a system loaded with registered memory with the idea of
>
> running
> > coreboot, unless it is known to work.
>
> I think (and hope) that I didn't mark any board as quad rank capable
> that wasn't marked that way before, but I can't tell if the original
> options are set correctly.
>
> In this regard, the tree with this patch is as good as without.

Agreed.

Acked-by: Myles Watson

Thanks,
Myles