Here is another opinion from a second TPM device driver developer.
-------- Mensagem original --------
Assunto: Re: [tpmdd-devel] Fwd: Re: [TrouSerS-tech] Fwd: Re: ST33 I2C
TPM issues
Data: Sun, 10 Nov 2013 23:36:54 +0100
De: Peter Hüwe <[email protected]>
Para: [email protected]
CC: Jason Gunthorpe <[email protected]>, Richard
<[email protected]>
These days we have the general assumption that the TPM is usable by
the kernel immediately after the driver is finished, so we can no
longer defer the mandatory self test to userspace.
In previous times the setup was done by the bios/firmware - with the tpm being
used in the embedded space (without a tpm aware firmware) the kernel has to
take over the responsibility. (similar to TPM_Startup).
As a related question - if anyone knows a reason why some drivers
don't call, or shouldn't call tpm_do_selftest, please share :)
There might be two reasons:
- boot time
TPMs are pretty slow devices and thus might add some boot time even if they
aren't used afterwards at all.
- pollution/discarding of the previous selftest result
but that's not really important for a user.
However imho the driver should call tpm_do_selftest in order to make the tpm
usable for the user.
Thanks,
Peter
------------------------------------------------------------------------------
November Webinars for C, C++, Fortran Developers
Accelerate application performance with scalable programming models. Explore
techniques for threading, error checking, porting, and tuning. Get the most
from the latest Intel processors and coprocessors. See abstracts and register
http://pubads.g.doubleclick.net/gampad/clk?id=60136231&iu=/4140/ostg.clktrk
_______________________________________________
TrouSerS-tech mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/trousers-tech
