On Mon, Apr 13, 2020 at 12:04:25PM +0200, Hans de Goede wrote:
> Hi Jarkko,
>
> On 4/12/20 7:04 PM, Jarkko Sakkinen wrote:
> > Call devm_free_irq() if we have to revert to polling in order not to
> > unnecessarily reserve the IRQ for the life-cycle of the driver.
> >
> > Cc: stable@xxxxxxxxxxxxxxx # 4.5.x
> > Reported-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> > Fixes: e3837e74a06d ("tpm_tis: Refactor the interrupt setup")
> > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
> > ---
> > drivers/char/tpm/tpm_tis_core.c | 5 ++++-
> > 1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
> > index 27c6ca031e23..ae6868e7b696 100644
> > --- a/drivers/char/tpm/tpm_tis_core.c
> > +++ b/drivers/char/tpm/tpm_tis_core.c
> > @@ -1062,9 +1062,12 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
> > if (irq) {
> > tpm_tis_probe_irq_single(chip, intmask, IRQF_SHARED,
> > irq);
> > - if (!(chip->flags & TPM_CHIP_FLAG_IRQ))
> > + if (!(chip->flags & TPM_CHIP_FLAG_IRQ)) {
> > dev_err(&chip->dev, FW_BUG
> > "TPM interrupt not working, polling instead\n");
> > + devm_free_irq(chip->dev.parent, priv->irq,
> > + chip);
> > + }
>
> My initial plan was actually to do something similar, but if the probe code
> is actually ever fixed to work as intended again then this will lead to a
> double free as then the IRQ-test path of tpm_tis_send() will have called
> disable_interrupts() which already calls devm_free_irq().
>
> You could check for chip->irq != 0 here to avoid that.
>
> But it all is rather messy, which is why I went with the "#if 0" approach
> in my patch.
I think it is right way to fix it. It is a bug independent of the issue
we are experiencing.
However, what you are suggesting should be done in addition. Do you have
a patch in place or do you want me to refine mine?
/Jarkko
