[PATCH 1/1] tpm: call tpm_tis_wait_init() after tpm_tis_init()

[Simon Glass]

Hi Ilias

On Mon, 22 Jul 2024 at 08:35, Ilias Apalodimas
<ilias.apalodimas at linaro.org> wrote:
>
> Hi all
>
> On Sun, 21 Jul 2024 at 13:08, Simon Glass <sjg at chromium.org> wrote:
> >
> > Hi,
> >
> > On Mon, 15 Jul 2024 at 12:23, <lukas.funke-oss at weidmueller.com> wrote:
> > >
> > > From: Lukas Funke <lukas.funke at weidmueller.com>
> > >
> > > tpm_tis_wait_init() is using the 'chip->timeout_b' field which is
> > > initialized in tpm_tis_init(). However, the init-function is called
> > > *after* tpm_tis_wait_init() introducing an uninitalized field access.
> > >
> > > This commit switches both routines.
> > >
> > > Signed-off-by: Lukas Funke <lukas.funke at weidmueller.com>
> > > ---
> > >
> > >  drivers/tpm/tpm2_tis_spi.c | 10 +++++-----
> > >  1 file changed, 5 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/drivers/tpm/tpm2_tis_spi.c b/drivers/tpm/tpm2_tis_spi.c
> > > index b0fe97ab1d0..5a4dbfd3ccb 100644
> > > --- a/drivers/tpm/tpm2_tis_spi.c
> > > +++ b/drivers/tpm/tpm2_tis_spi.c
> > > @@ -256,17 +256,17 @@ static int tpm_tis_spi_probe(struct udevice *dev)
> > >         /* Ensure a minimum amount of time elapsed since reset of the TPM */
> > >         mdelay(drv_data->time_before_first_cmd_ms);
> > >
> > > +       tpm_tis_ops_register(dev, &phy_ops);
> > > +       ret = tpm_tis_init(dev);
> > > +       if (ret)
> > > +               goto err;
> > > +
> > >         ret = tpm_tis_wait_init(dev, chip->locality);
> > >         if (ret) {
> > >                 log(LOGC_DM, LOGL_ERR, "%s: no device found\n", __func__);
> > >                 return ret;
> > >         }
> > >
> > > -       tpm_tis_ops_register(dev, &phy_ops);
> > > -       ret = tpm_tis_init(dev);
> > > -       if (ret)
> > > -               goto err;
> > > -
> > >         priv->pcr_count = drv_data->pcr_count;
> > >         priv->pcr_select_min = drv_data->pcr_select_min;
> > >         priv->version = TPM_V2;
> > > --
> > > 2.30.2
> > >
> >
> > This needs a Fixes tag for a5c30c26b28 (HEAD) tpm: Use the new API on
> > tpm2 spi driver
> >
>
> Yes please we need a fixes tag
>
> > The old code set up the timeouts first, then did the wait_init.
> > Presumably the point of wait_init is to wait before doing the init, so
> > we should try to keep that behaviour, unless it is actually wrong.
> >
> > So my thought would be to move the setup of the required timeout into
> > tpm_tis_ops_register(), instead.
>
> tpm_tis_ops_register() is setting up the bus accesses and I'd prefer
> to keep it that way.
> Since this is a static function, we can fold it in tpm_tis_init(),
> which makes more sense

Since this is used by i2c and SPI we need to make sure that both work.

I believe the way it used to be, some initial values were set for the
timeouts. The naming is somewhat confusing I suppose.

Regards,
Simon