On Fri, Jun 08, 2018 at 12:36:18PM -0700, flihp wrote: > On 06/04/2018 12:55 PM, Jarkko Sakkinen wrote: > > On Thu, May 31, 2018 at 04:29:09PM -0700, Tadeusz Struk wrote: > >> The TCG SAPI specification [1] defines a set of functions, which allows > >> applications to use the TPM device in either blocking or non-blocking fashion. > >> Each command defined by the specification has a corresponding > >> Tss2_Sys_<COMMAND>_Prepare() and Tss2_Sys_<COMMAND>_Complete() call, which > >> together with Tss2_Sys_ExecuteAsync() is designed to allow asynchronous > >> mode of operation. Currently the driver supports only blocking calls, which > >> doesn't allow asynchronous operation. This patch changes it and adds support > >> for nonblocking write and a new poll function to enable applications using > >> the API as designed by the spec. > >> The new functionality can be tested using standard TPM tools implemented > >> in [2], with modified TCTI from [3]. > > > > I would need some statistics before I have interest to take these > > changes in any form eg use case where this matters in the end. > > The use cases motivating this feature are the same ones that motivated > the non-blocking behavior of other kernel interfaces (files, sockets and > other hardware) that has the potential to block threads in a process. By > implementing this same behavior in the TPM driver our goal is to enable > use of the TPM in programming languages / frameworks implementing an > "event-driven" model. There are a lot of them out there but since the > TSS2 APIs are currently limited to C our example code is in glib / GSource. > > Hopefully this is sufficient but if it isn't it would help us to get > additional details on what you're looking for. Thanks Philip. I'll look into the patch itself. /Jarkko
