On Wed, May 05, 2021 at 01:15:29AM +0200, Lino Sanfilippo wrote: > Hi, > > On 03.05.21 at 17:50, Jarkko Sakkinen wrote: > > What the heck is "simplification" and what that has to do with fixing > > anything? I don't understand your terminology. > > > The intention for this patch is not to fix anything. Please read the cover > letter and the commit message. > This patch is about making the locality handling easier by not claiming/releasing > it multiple times over the driver life time, but claiming it once at driver > startup and only releasing it at driver shutdown. > > Right now we have locality request/release combos in > > - probe_itpm() > - tpm_tis_gen_interrupt() > - tpm_tis_core_init() > - tpm_chip_start() > > and there is still one combo missing for > > - tpm2_get_timeouts() > > which is the reason why we get the "TPM returned invalid status" bug in case > of TPM2 (and this is the bug which is _incidentally_ fixed by this patch, see > below). > > And if we are going to enable interrupts, we have to introduce yet another combo, > for accessing the status register in the interrupt handler, since TPM 2.0 > requires holding the locality for writing to the status register. That makes > 6 different code places in which we take and release the locality. > > With this patch applied we only take the locality at one place. Furthermore > with interrupts enabled we dont have to claim the locality for each handler > execution, saving us countless claim/release combinations at runtime. > > Hence the term "simplification" which is perfectly justified IMO. > > So again, this patch is "only" in preparation for the next patch when interrupts > are actually enabled and we would have to take the locality in the interrupt > handler without this patch. So: what problem this patch does solve? /Jarkko
