Messages in this thread | | | Date | Mon, 25 Jan 2021 09:18:46 -0800 | From | Guenter Roeck <> | Subject | Re: [PATCH] tpm_tis: Add missing start/stop_tpm_chip calls |
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Hi Lukasz,
On Sat, Jan 23, 2021 at 02:42:47AM +0100, Lukasz Majczak wrote: > There is a missing call to start_tpm_chip before the call to > the tpm_get_timeouts() and tpm_tis_probe_irq_single(). As the current > approach maight work for tpm2, it fails for tpm1.x - in that case > call to tpm_get_timeouts() or tpm_tis_probe_irq_single() tries to > transmit TPM commands on a disabled chip what what doesn't succeed
s/what what/what/
> and in turn causes tpm_tis_core_init() to fail. > Tested on Samsung Chromebook Pro (Caroline). > > Signed-off-by: Lukasz Majczak <lma@semihalf.com> > --- > drivers/char/tpm/tpm_tis_core.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c > index 92c51c6cfd1b..ff0e5fe46a9d 100644 > --- a/drivers/char/tpm/tpm_tis_core.c > +++ b/drivers/char/tpm/tpm_tis_core.c > @@ -1063,12 +1063,16 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq, > init_waitqueue_head(&priv->read_queue); > init_waitqueue_head(&priv->int_queue); > if (irq != -1) { > + rc = tpm_chip_start(chip);
Unless I am missing something, the underlying problem seems to be the calls to tpm1_getcap(). From other code calling this function, it looks like it may only require tpm_clk_enable() to work.
With that in mind, would it possibly be better to call tpm_clk_enable() and tpm_clk_disable() around the calls to tpm1_getcap(), ie in tpm1_get_timeouts() and in tpm_tis_gen_interrupt() ?
This would avoid the unnecessary calls to tpm_chip_start() and tpm_chip_stop() for tpm2 chips.
Thanks, Guenter
> + if (rc) > + goto out_err; > /* Before doing irq testing issue a command to the TPM in polling mode > * to make sure it works. May as well use that command to set the > * proper timeouts for the driver. > */ > if (tpm_get_timeouts(chip)) { > dev_err(dev, "Could not get TPM timeouts and durations\n"); > + tpm_chip_stop(chip); > rc = -ENODEV; > goto out_err; > } > @@ -1085,6 +1089,7 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq, > } else { > tpm_tis_probe_irq(chip, intmask); > } > + tpm_chip_stop(chip); > } > > rc = tpm_chip_register(chip);
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