Messages in this thread | | | Date | Wed, 9 Aug 2023 12:31:56 +0530 | Subject | Re: [PATCH V3 1/4] arm_pmu: acpi: Refactor arm_spe_acpi_register_device() | From | Anshuman Khandual <> |
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On 8/8/23 18:51, Will Deacon wrote: > On Mon, Aug 07, 2023 at 11:03:40AM +0530, Anshuman Khandual wrote: >> On 8/4/23 22:09, Will Deacon wrote: >>> On Thu, Aug 03, 2023 at 11:43:27AM +0530, Anshuman Khandual wrote: >>>> On 8/3/23 11:26, Anshuman Khandual wrote: >>>>> + /* >>>>> + * Sanity check all the GICC tables for the same interrupt >>>>> + * number. For now, only support homogeneous ACPI machines. >>>>> + */ >>>>> + for_each_possible_cpu(cpu) { >>>>> + struct acpi_madt_generic_interrupt *gicc; >>>>> + >>>>> + gicc = acpi_cpu_get_madt_gicc(cpu); >>>>> + if (gicc->header.length < len) >>>>> + return gsi ? -ENXIO : 0; >>>>> + >>>>> + this_gsi = parse_gsi(gicc); >>>>> + if (!this_gsi) >>>>> + return gsi ? -ENXIO : 0; >>>> >>>> Moved parse_gsi() return code checking to its original place just to >>>> make it similar in semantics to existing 'gicc->header.length check'. >>>> If 'gsi' is valid i.e atleast a single cpu has been probed, return >>>> -ENXIO indicating mismatch, otherwise just return 0. >>> >>> Wouldn't that still be the case without the check in this hunk? We'd run >>> into the homogeneous check and return -ENXIO from there, no? >> Although the return code will be the same i.e -ENXIO, but not for the same reason. >> >> this_gsi = parse_gsi(gicc); >> if (!this_gsi) >> return gsi ? -ENXIO : 0; >> >> This returns 0 when IRQ could not be parsed for the first cpu, but returns -ENXIO >> for subsequent cpus. Although return code -ENXIO here still indicates IRQ parsing >> to have failed. >> >> } else if (hetid != this_hetid || gsi != this_gsi) { >> pr_warn("ACPI: %s: must be homogeneous\n", pdev->name); >> return -ENXIO; >> } >> >> This returns -ENXIO when there is a IRQ mismatch. But if the above check is not >> there, -ENXIO return code here could not be classified into IRQ parse problem or >> mismatch without looking into the IRQ value. > > Sorry, but I don't understand your point here. If any of this fails, there's > going to be some debugging needed to look at the ACPI tables; the only > difference with my suggestion is that you'll get a message indicating that > the devices aren't homogeneous, which I think is helpful.
I dont have strong opinion either way. Hence will move 'this_gsi' check inside the !gsi conditional check like you had suggested earlier.
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