ioread8() operations to TPM MMIO addresses can stall the cpu when
immediately following a sequence of iowrite*()'s to the same region.
For example, cyclitest measures ~400us latency spikes when a non-RT
usermode application communicates with an SPI-based TPM chip (Intel Atom
E3940 system,
The patch simply replaces all msleep function calls with usleep_range calls
in the generic drivers.
Tested with an Infineon TPM 1.2, using the generic tpm-tis module, for a
thousand PCR extends, we see results going from 1m57s unpatched to 40s
with the new patch. We obtain similar results when
On Mon, 2017-08-14 at 13:56 +0300, Jarkko Sakkinen wrote:
> > > Since the main concern about this change is breaking old systems that
> > > might potentially have other peripherals hanging off the LPC bus, can
> > > we define a new Kconfig option, with the default as 'N'?
> > >
> > > Mimi
> >
>
On Mon, 2017-08-14 at 13:56 +0300, Jarkko Sakkinen wrote:
> > > > I would like to see tpm_msleep() wrapper to replace current msleep()
> > > > usage across the subsystem before considering this. I.e. wrapper that
> > > > internally uses usleep_range(). This way we can mechanically convert
> > > >
On Mon, Aug 14, 2017 at 01:51:30PM +0300, Jarkko Sakkinen wrote:
> On Fri, Aug 11, 2017 at 11:30:19AM -0400, Mimi Zohar wrote:
> > On Fri, 2017-08-11 at 14:14 +0300, Jarkko Sakkinen wrote:
> > > On Wed, Aug 09, 2017 at 11:00:36PM +0200, Peter Huewe wrote:
> > > > Hi Ken,
> > > > (again speaking
On Sat, Aug 12, 2017 at 08:22:49PM -0500, Jiandi An wrote:
> For ARM64, the locality is handled by Trust Zone in FW.
> The layout does not have crb_regs_head. It is hitting
> the following line.
> dev_warn(dev, FW_BUG "Bad ACPI memory layout");
>
> Current code excludes CRB_FL_ACPI_START and
On Fri, Aug 11, 2017 at 03:44:43PM +0200, Michal Suchanek wrote:
> As seen from the implementation of the single class shutdown hook this
> is not very sound design.
>
> Rename the class shutdown hook to shutdown_pre to make it clear it runs
> before the driver shutdown hook.
>
> Signed-off-by:
