Atmel has updated the ATmega324PA datasheet.  It now uses names like "SPCR0" in the tables that define the registers, but they still have plenty of example code and wording in paragraphs that refer to "SPCR".

The ATmega164PA datasheet still does not use the name "SPCR0", so users of that chip will have trouble due to the missing register names in avr-libc.

I submitted this patch 15 months ago and I thought it would be pretty straightforward.  Are there any issues with it?

An Atmel tech support representative has told me that he will file a bug report, but did not give any other useful information.

While I was researching my bug report to Atmel, I noticed a new part definition file in Atmel Studio 7.0.934: the ATmega324PB.  This part will have two SPI modules, so it makes sense that all of its SPI registers and bits are suffixed with 0 and 1.  I suspect that Atmel is purposely renaming the SPI registers on the old parts for consistency's sake.  They renamed the SPI registers for the ATmega164{A,P,PA} and ATmega324{A,P,PA}, but they have not yet done it for the ATmega644* or ATmega1284*.

I will still contact them anyway, because I noticed an inconsistency: in ATmega164A.atdf they defined a bit to be named SPR01 when they really meant SPR10.  That's definitely an error, but in general their adding of these prefixes might not be an error.

Actuall, the datasheet is inconsistent on this: in the register
summary at the end, the bits do have the 0 suffix, while the
description omits them.

Likewise, the Atmel Studio XML files (where our header files
have been derived from) also uses the 0 suffix.

So please file a bug report with Atmel so they get all their
documentation and description files consistent.

Due to the inconsistencies, I think the way for us to fix it
is by supplying both definitions.