On 2020-10-01 10:12, Miquel Raynal wrote: > Hi Jann, > > Jann Horn <jannh@xxxxxxxxxx> wrote on Thu, 1 Oct 2020 00:32:24 +0200: > >> On Wed, Sep 30, 2020 at 11:30 PM Gustavo A. R. Silva >> <gustavoars@xxxxxxxxxx> wrote: >> > On Wed, Sep 30, 2020 at 11:10:43PM +0200, Jann Horn wrote: >> > > On Wed, Sep 30, 2020 at 11:02 PM Gustavo A. R. Silva >> > > <gustavoars@xxxxxxxxxx> wrote: >> > > > There is a regular need in the kernel to provide a way to declare having >> > > > a dynamically sized set of trailing elements in a structure. Kernel code >> > > > should always use “flexible array members”[1] for these cases. The older >> > > > style of one-element or zero-length arrays should no longer be used[2]. >> > > >> > > But this is not such a case, right? Isn't this a true fixed-size >> > > array? It sounds like you're just changing it because it >> > > pattern-matched on "array of length 1 at the end of a struct". >> > >> > Yeah; I should have changed that 'dynamically' part of the text above >> > a bit. However, as I commented in the text below, in the case that more >> > CS IDs are needed (let's wait for the maintainers to comment on this...) >> > in the future, this change makes the code more maintainable, as for >> > the allocation part, the developer would only have to update the CS_N >> > macro to the number of CS IDs that are needed. >> >> But in that case, shouldn't you change it to "int cs[CS_N]" and get >> rid of the struct_size() stuff? > > I do agree with Jann, I think it's best to consider this a fixed-size > array for now. If we ever want to extend the number of supported CS, > there is much more rework involved anyway. I agree, too, just assume this is a fixed-size array of 1 element. In fact, I am not aware of a design which needs multiple chip selects. -- Stefan
