Commit 4985c32e authored by Lan Tianyu's avatar Lan Tianyu Committed by Rafael J. Wysocki

ACPI / processor: Fix failure of loading acpi-cpufreq driver

According commit d640113f (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 b981513f (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: b981513f (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+ <stable@vger.kernel.org> # 3.14+
Reported-and-tested-by: default avatarKATO Hiroshi <katoh@mikage.ne.jp>
Reported-and-tested-by: default avatarStuart Foster <smf.linux@ntlworld.com>
Signed-off-by: default avatarLan Tianyu <tianyu.lan@intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent d1db0eea
......@@ -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;
......@@ -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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