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ACPI / processor: Fix failure of loading acpi-cpufreq driver
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According commit d640113 (ACPI: processor: fix acpi_get_cpuid for UP
processor),  BIOS may not provide _MAT or MADT tables and acpi_get_apicid()
always returns -1. For these cases, original code will pass apic_id with
vaule of -1 to acpi_map_cpuid() and it will check the acpi_id. If acpi_id
is equal to zero, ignores apic_id and return zero for CPU0.

Commit b981513 (ACPI / scan: bail out early if failed to parse APIC
ID for CPU) changed the behavior. Return ENODEV when find apic_id is
less than zero after calling acpi_get_apicid(). This causes acpi-cpufreq
driver fails to be loaded on some machines. This patch is to fix it.

Fixes: b981513 (ACPI / scan: bail out early if failed to parse APIC ID for CPU)
References: https://bugzilla.kernel.org/show_bug.cgi?id=73781
Cc: 3.14+ <[email protected]> # 3.14+
Reported-and-tested-by: KATO Hiroshi <[email protected]>
Reported-and-tested-by: Stuart Foster <[email protected]>
Signed-off-by: Lan Tianyu <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
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Lan Tianyu authored and rafaeljw committed Apr 30, 2014
1 parent d1db0ee commit 4985c32
Showing 1 changed file with 4 additions and 3 deletions.
7 changes: 4 additions & 3 deletions drivers/acpi/acpi_processor.c
Original file line number Diff line number Diff line change
Expand Up @@ -170,6 +170,9 @@ static int acpi_processor_hotadd_init(struct acpi_processor *pr)
acpi_status status;
int ret;

if (pr->apic_id == -1)
return -ENODEV;

status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta);
if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT))
return -ENODEV;
Expand Down Expand Up @@ -260,10 +263,8 @@ static int acpi_processor_get_info(struct acpi_device *device)
}

apic_id = acpi_get_apicid(pr->handle, device_declaration, pr->acpi_id);
if (apic_id < 0) {
if (apic_id < 0)
acpi_handle_debug(pr->handle, "failed to get CPU APIC ID.\n");
return -ENODEV;
}
pr->apic_id = apic_id;

cpu_index = acpi_map_cpuid(pr->apic_id, pr->acpi_id);
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