On Tue, Oct 11, 2016 at 10:21:03AM +0000, Winkler, Tomas wrote:
> > Encapsulated crb_wait_for_reg32() so that state changes in other CRB
> > registers
> > than TPM_CRB_CTRL_REQ_x can be waited.
> >
> > Signed-off-by: Jarkko Sakkinen <jarkko.sakki...@linux.intel.com>
> > ---
> > drivers/char/tpm/tpm_crb.c | 40 +++++++++++++++++++++++-----------------
> > 1 file changed, 23 insertions(+), 17 deletions(-)
> >
> > diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c index
> > c34318b..45f53c2 100644
> > --- a/drivers/char/tpm/tpm_crb.c
> > +++ b/drivers/char/tpm/tpm_crb.c
> > @@ -121,6 +121,25 @@ static int __maybe_unused crb_go_idle(struct device
> > *dev, struct crb_priv *priv)
> > return 0;
> > }
> >
> > +static bool crb_wait_for_reg_32(u32 __iomem *reg, u32 mask, u32 value,
> > + unsigned long timeout)
> This is a boiler plate register polling function I would call it _poll_
> rather the _wait_
>
> > +{
> > + ktime_t start;
> > + ktime_t stop;
> > +
> > + start = ktime_get();
> > + stop = ktime_add(start, ms_to_ktime(timeout));
> > +
> > + do {
> > + if ((ioread32(reg) & mask) == value)
> I prefer the register value is synced to variable, this inlining is
> harder to add adhoc debug prints. Also you removed the debug print
> out that I know when this settled which is important for catching
> bugs.
I can add it but can you just briefly explain why the warning
is not enough?
> > + return true;
> > +
> > + usleep_range(50, 100);
> How do you know this is correct sleep time, I've tuned that for power
> gating I'm not sure you this fits also for locality.
Does it matter as long as it is less than for the timeout?
/Jarkko
