Messages in this thread | | | Subject | Re: [PATCH] tpm/tpm_tis: Free IRQ if probing fails | From | Hans de Goede <> | Date | Tue, 14 Apr 2020 19:15:08 +0200 |
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Hi,
On 4/14/20 6:45 PM, Jarkko Sakkinen wrote: > On Tue, Apr 14, 2020 at 07:04:07PM +0300, Jarkko Sakkinen wrote: >> On Tue, Apr 14, 2020 at 10:26:32AM +0200, Hans de Goede wrote: >>> Hi, >>> >>> On 4/14/20 9:13 AM, Jarkko Sakkinen wrote: >>>> On Mon, Apr 13, 2020 at 08:11:15PM +0200, Hans de Goede wrote: >>>>> Hi, >>>>> >>>>> On 4/13/20 8:07 PM, Jarkko Sakkinen wrote: >>>>>> 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@vger.kernel.org # 4.5.x >>>>>>>> Reported-by: Hans de Goede <hdegoede@redhat.com> >>>>>>>> Fixes: e3837e74a06d ("tpm_tis: Refactor the interrupt setup") >>>>>>>> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> >>>>>>>> --- >>>>>>>> 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. >>> >>> Erm in case you haven't figured it out yet this should be priv->irq != 0, sorry. >> >> Yup. >> >>>>>>> >>>>>>> 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? >>>>> >>>>> I do not have a patch ready for this, if you can refine yours that would >>>>> be great. >>>> >>>> Thanks! Just wanted to confirm. >>> >>> And thank you for working on a (temporary?) fix for this. >> >> As far as I see it, it is orthogonal fix that needs to be backported >> to stable kernels. This bug predates the issue we're seeing now. > > Hey, I came to other thoughts on "how". Would probably make sense > to always call disable_interrupts() aka no sense to add two separate > code paths. What do you think?
Sounds good, I guess it would be best to combine that with a:
if (priv->irq == 0) return;
At the top of disable_interrupts() and then unconditionally call disable_interrupts() where your v1 of this patch calls devm_free_irq(). That would be a reasonable clean solution I think.
Regards,
Hans
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