Hi Rafał, rafal@xxxxxxxxxx wrote on Fri, 06 Oct 2023 13:41:52 +0200: > On 2023-10-05 17:59, Miquel Raynal wrote: > > At a first look it might seem that the presence of the of_node pointer > > in the nvmem device does not matter much, but in practice, after > looking > > deep into the DT core, nvmem_add_cells_from_dt() will simply and always > > return NULL if this field is not provided. As most mtd devices don't > > populate this field (this could evolve later), it means none of their > > children cells will be populated unless no_of_node is explicitly set to > > false. In order to clarify the logic, let's add clear check at the > > beginning of this helper. > > I'm somehow confused by above explanation and code too. I read it > carefully 5 times but I can't see what exactly this change helps with. > > At first look at nvmem_add_cells_from_legacy_of() I can see it uses > "of_node" so I don't really agree with "it might seem that the presence > of the of_node pointer in the nvmem device does not matter much". > > You really don't need to look deep into DT core (actually you don't have > to look into it at all) to understand that nvmem_add_cells_from_dt() > will return 0 (nitpicking: not NULL) for a NULL pointer. It's all made > of for_each_child_of_node(). Obviously it does nothing if there is > nothing to loop over. That was not obvious to me as I thought it would start from /, which I think some other function do when you don't provide a start node. > Given that for_each_child_of_node() is NULL-safe I think code from this > patch is redundant. I didn't say it was not safe, just not explicit. > Later you mention "no_of_node" which I agree to be a very non-intuitive > config option. As pointed in another thread I already sent: > [PATCH] Revert "nvmem: add new config option" > https://lore.kernel.org/lkml/ba3c419a-6511-480a-b5f2-6c418f9c02e7@xxxxxxxxx/t/ I actually wanted to find again that patch and could not get my hands on it, but it is probably a much better fix than my other mtd patch, I agree with you. > Maybe with above patch finally things will get more clear and we don't > need this PATCH after all? Yes. Srinivas, what are your plans for the above patch? Thanks, Miquèl
