Hi Jason, On 24 October 2017 at 23:16, Jason Gunthorpe <jgunthorpe@xxxxxxxxxxxxxxxxxxxx> wrote: > On Tue, Oct 24, 2017 at 09:44:30PM +0530, PrasannaKumar Muralidharan wrote: > >> I am wondering why it is wrong. Isn't the chip id valid till it is >> unregistered? If so the rfc is correct. Please explain, may be I am >> missing something. > > The lifetime is a bit complicated, but the general rule in the kernel > for things like this it to use pointers, not ids, and certainly not > string ids. > > For that patch it could just use container_of to get the chip.. > > Jason hwrng requires a unique name for every device. In that patch "tpm-rng-<chip_num>" is used. chip_num is nothing but dev->dev_num. This way more than 1 tpm chip can be used as rng provider. tpm_get_random uses chip_num as its parameter. This is why chip->dev_num was used. Is that reasoning correct? Please feel free to correct me if I am wrong. Thanks, PrasannaKumar
