On Sun Oct 19, 2025 at 8:57 PM JST, Daniel del Castillo wrote:
>>> @@ -296,24 +287,19 @@ fn new_fwsec(dev: &Device<device::Bound>, bios:
>>> &Vbios, cmd: FwsecCommand) -> Re
>>> size: 0,
>>> flags: 2,
>>> };
>>> -
>>> - dmem_mapper.init_cmd = match cmd {
>>> - FwsecCommand::Frts {
>>> - frts_addr,
>>> - frts_size,
>>> - } => {
>>> - frts_cmd.frts_region = FrtsRegion {
>>> - ver: 1,
>>> - hdr: size_of::<FrtsRegion>() as u32,
>>> - addr: (frts_addr >> 12) as u32,
>>> - size: (frts_size >> 12) as u32,
>>> - ftype: NVFW_FRTS_CMD_REGION_TYPE_FB,
>>> - };
>>> -
>>> - NVFW_FALCON_APPIF_DMEMMAPPER_CMD_FRTS
>>> - }
>>> - FwsecCommand::Sb => NVFW_FALCON_APPIF_DMEMMAPPER_CMD_SB,
>>> - };
>>> + if let FwsecCommand::Frts {
>>> + frts_addr,
>>> + frts_size,
>>> + } = cmd
>>> + {
>>> + frts_cmd.frts_region = FrtsRegion {
>>> + ver: 1,
>>> + hdr: size_of::<FrtsRegion>() as u32,
>>> + addr: (frts_addr >> 12) as u32,
>>> + size: (frts_size >> 12) as u32,
>>> + ftype: NVFW_FRTS_CMD_REGION_TYPE_FB,
>>> + };
>>> + }
>>
>> I liked that the original code updated both `init_cmd` and `frts_region`
>> in the same match block. I understand it might be difficult to preserve
>> due to the borrowing rules, but can you try to preserve it if that's
>> possible at all?
>
> I agree it was nicer. I tried to preserve it, but I don't see a way to
> do it cleanly, as I can't keep both mutable references at the same time.
> What I could do is only check `cmd` once, set `init_cmd` and store an
> `Option<FrtsRegion>` that I will later use to set `frts_region` if it's
> not `None`. Let me know if you prefer that.
Yeah, I agree the borrow checker will get in the way now that we have
fixed the lifetimes.
What I wanted to avoid is performing the same match operation on `cmd`
twice, but if that's difficult then I guess we can live with it. Using a
temporary `Option` comes down to the same in the end, except that the
second test is indirect.
