Messages in this thread | | | From | "Wilck, Martin" <> | Date | Mon, 7 Dec 2015 10:52:51 +0100 | Subject | Re: [tpmdd-devel] [PATCH v2 0/3] tpm_tis: Clean up force module parameter |
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> > > You can completely ignore this question. I saw Martins reply with a fix for > > > "tpm_tis: Use devm_ioremap_resource" that you should squash into that > > > change. So it's proved that TPM ACPI device objects do not always have a > > > memory resource. Good. > > > > Repeat, the memory resource DOES exist on my system. Not sure what proof > > you saw there. > > Ok, lets go this through. > > I deduced this from two facts: > > * It used to have memory resource as conditional and as a fallback use > fixed value. > * Your workaround reverted the situation to this. > > Did I understand something incorrectly?
The problem in my case didn't occur because ACPI was lacking a resource. It has one "extra" resource that Jason's original code didn't recognize.
Jason's code was wrongly assuming that a resource that isn't of type "IRQ" has to be of type "MEMORY". If I print out the resource types encountered in tpm_check_resource(), I get ACPI_RESOURCE_TYPE_FIXED_MEMORY32 (0x0a) first, followed by ACPI_RESOURCE_TYPE_END_TAG (0x07). The latter was mistakenly used by Jason't code as a memory resource. This is how ACPI ResourceTemplates work (a list with an end marker). The correct solution is to always check the return value of acpi_dev_resource_memory(), as it's currently implemented in Jason't current "for-jarkko" branch.
Martin
> > /Jarkko
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