On Wed, Oct 09, 2024 at 03:19:59PM GMT, Matias Bjørling wrote: > On 09-10-2024 09:46, Christoph Hellwig wrote: > > On Tue, Oct 08, 2024 at 04:55:02PM +0200, Matias Bjørling wrote: > > > However, the independent namespace data structure > > > is mandatory for devices that implement features from the 2.0+ > > > specification. Therefore, we can check this data structure first. If > > > unavailable, retrieve the generic attributes from the NVM command set > > > identify namespace data structure. > > > > I'm not a huge fan of this. For pre-2.0 controllers this means > > we'll now send a command that will fail most of them time. And for > > all the cheap low-end consumer device I'm actually worried that they'll > > get it wrong and break something. > > > > It's a good point. Damien, Keith, and I were debating it during ALPSS. They > preferred the "send command and see if it fails" approach over writing > specific conditions where it would apply. Note that Keith did suggest to > avoid the command on 1.0 and 1.1 devices, and they were known to fail with > unsupported CNS ids. FWIW, there are some devices out there which will log these attempts and spam their error logs. There were plenty of reports against nvme-cli when nvme-cli issued a command which could fail.
