On Mon, Dec 07, 2020 at 11:58:44AM -0800, James Bottomley wrote: > On Mon, 2020-12-07 at 15:28 -0400, Jason Gunthorpe wrote: > > On Sun, Dec 06, 2020 at 08:26:16PM +0100, Thomas Gleixner wrote: > > > Just as a side note. I was looking at tpm_tis_probe_irq_single() > > > and that function is leaking the interrupt request if any of the > > > checks afterwards fails, except for the final interrupt probe check > > > which does a cleanup. That means on fail before that the interrupt > > > handler stays requested up to the point where the module is > > > removed. If that's a shared interrupt and some other device is > > > active on the same line, then each interrupt from that device will > > > call into the TPM code. Something like the below is needed. > > > > > > Also the X86 autoprobe mechanism is interesting: > > > > > > if (IS_ENABLED(CONFIG_X86)) > > > for (i = 3; i <= 15; i++) > > > if (!tpm_tis_probe_irq_single(chip, intmask, 0, > > > i)) > > > return; > > > > > > The third argument is 'flags' which is handed to request_irq(). So > > > that won't ever be able to probe a shared interrupt. But if an > > > interrupt number > 0 is handed to tpm_tis_core_init() the interrupt > > > is requested with IRQF_SHARED. Same issue when the chip has an > > > interrupt number in the register. It's also requested exclusive > > > which is pretty likely to fail on ancient x86 machines. > > > > It is very likely none of this works any more, it has been repeatedly > > reworked over the years and just left behind out of fear someone > > needs it. I've thought it should be deleted for a while now. > > > > I suppose the original logic was to try and probe without SHARED > > because a probe would need exclusive access to the interrupt to tell > > if the TPM was actually the source, not some other device. > > > > It is all very old and very out of step with current thinking, IMHO. > > I skeptical that TPM interrupts were ever valuable enough to deserve > > this in the first place. > > For what it's worth, I agree. Trying to probe all 15 ISA interrupts is > last millennium thinking we should completely avoid. If it's not > described in ACPI then you don't get an interrupt full stop. > > James Maybe you could add this as part of your patches? /Jarkko _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
