Wolfgang Denk writes:
Wolfgang> In message 16469.31569.535909.246506@gargle.gargle.HOWL Wolfgang> you wrote:
Wolfgang> Are you 100% sure this does not break any existing boards?
Yuli> I checked it on four different boards with different PQ2 Yuli> chips. In fact, for older (pre-PQ27e) chips this patch does Yuli> not change memory map so they aren't affected in any way. Am I Yuli> missing anything?
Wolfgang> I don't know. I just want to understand the consequences.
Wolfgang> + gd->CPM_DATAONLY_SIZE; Wolfgang> + if (is_pq27e()) Wolfgang> + gd->dp_alloc_top = gd->dp_alloc_base Wolfgang> + gd->PQ27E_DATAONLY_SIZE; Wolfgang> + else Wolfgang> + gd->dp_alloc_top = gd->dp_alloc_base Wolfgang> + gd->CPM_DATAONLY_SIZE;
Wolfgang> First, ther is at least one redundand Wolfgang> "gd->CPM_DATAONLY_SIZE;" here.
No, no, it's just E-mail formatting of the excerpt after several replies. There is no redundant code in the patch.
Wolfgang> Please do not add a board-specific #define Wolfgang> PQ27E_DATAONLY_SIZE when we already have a Wolfgang> CPM_DATAONLY_SIZE which could be used.
Yuli> There should be some misunderstanding Yuli> here. PQ27E_DATAONLY_SIZE is NOT board-specific (I won't add Yuli> board-specific things into common files). PQ27e is the common Yuli> name for the 8247/8248/8271/8272 (the `e'
Wolfgang> Sorry for chosing a poor description.
Yuli> stands for `encryption'). These chips have got much less Yuli> internal memory (DPRAM) and at different addresses so they Yuli> must have separate Yuli> #defines. CPM_DATAONLY_SIZE is just incorrect for PQ27e. PQ27e Yuli> have got only 4K of "data only" RAM and not 8K (and at Yuli> different base, BTW).
Wolfgang> Why do you need a separate #define then? Isn't it Wolfgang> sufficient to Wolfgang> #define a correct value for CPM_DATAONLY_SIZE then?
This would require that, for every PQ27e-based board, it would be defined in the board configuration file that it's PQ27e and not just 8260. Then CPM_DATAONLY_SIZE can be defined conditionally on this definition in cpm_8260.h. I personally don't like such compile-time definitions because chip version can be easily detected in run-time.
Wolfgang> PQ27E_FCC_SPECIAL_BASE vs. CPM_FCC_SPECIAL_BASE
Yuli> It's for the same reason. PQ27e have not got RAM at 0xB000, Yuli> other PQ2s
Wolfgang> So why not just #define a correct value?
Yuli> After the explanations, what changes would you suggest?
Wolfgang> Use the existing variables and just assign correct values?
Well, the question is if it's better that the CPU-specific code will silently handle the differences or we'll make it the user's responsibility to define the difference manually. I think automatic handling is better but if you insist on #ifdefs, I can implement it too.