On 24/02/16 18:10, Aleksey Makarov wrote:
From: Leif Lindholm <leif.lindholm@xxxxxxxxxx>
In order to support selecting earlycon via either ACPI or DT, move
the decision on whether to attempt ACPI configuration into the
early_param handling. Then make acpi_boot_table_init() bail out if
acpi_disabled.
Signed-off-by: Leif Lindholm <leif.lindholm@xxxxxxxxxx>
Signed-off-by: Aleksey Makarov <aleksey.makarov@xxxxxxxxxx>
---
arch/arm64/kernel/acpi.c | 62 +++++++++++++++++++++++-------------------------
1 file changed, 30 insertions(+), 32 deletions(-)
diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
index d1ce8e2..3faa323 100644
--- a/arch/arm64/kernel/acpi.c
+++ b/arch/arm64/kernel/acpi.c
@@ -41,26 +41,8 @@ EXPORT_SYMBOL(acpi_disabled);
int acpi_pci_disabled = 1; /* skip ACPI PCI scan and IRQ initialization */
EXPORT_SYMBOL(acpi_pci_disabled);
-static bool param_acpi_off __initdata;
static bool param_acpi_force __initdata;
-static int __init parse_acpi(char *arg)
-{
- if (!arg)
- return -EINVAL;
-
- /* "acpi=off" disables both ACPI table parsing and interpreter */
- if (strcmp(arg, "off") == 0)
- param_acpi_off = true;
- else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */
- param_acpi_force = true;
- else
- return -EINVAL; /* Core will print when we return error */
-
- return 0;
-}
-early_param("acpi", parse_acpi);
-
static int __init dt_scan_depth1_nodes(unsigned long node,
const char *uname, int depth,
void *data)
@@ -74,6 +56,35 @@ static int __init dt_scan_depth1_nodes(unsigned long node,
return 0;
}
+static int __init parse_acpi(char *arg)
+{
+ if (!arg)
+ return -EINVAL;
+
+ /*
+ * Enable ACPI instead of device tree unless
+ * - ACPI has been disabled explicitly (acpi=off), or
+ * - the device tree is not empty (it has more than just a /chosen node)
+ * and ACPI has not been force enabled (acpi=force)
+ */
+ if (strcmp(arg, "off") == 0)
+ return 0;
+ else if (strcmp(arg, "force") == 0)
+ param_acpi_force = true;
+ else if (of_scan_flat_dt(dt_scan_depth1_nodes, NULL))
I think we should strcmp for "on" here and return an error on other
values. IMHO an update to Documentation/kernel-parameters.txt would be
convenient.
I still wonder if we really want to change the default to ACPI disabled.
But that's a decision the maintainers have to take.
Regards,
Matthias
+ return 0;
+
+ /*
+ * ACPI is disabled at this point. Enable it in order to parse
+ * the ACPI tables and carry out sanity checks
+ */
+ enable_acpi();
+
+ return 0;
+}
+
+early_param("acpi", parse_acpi);
+
/*
* __acpi_map_table() will be called before page_init(), so early_ioremap()
* or early_memremap() should be called here to for ACPI table mapping.
@@ -181,23 +192,10 @@ out:
*/
void __init acpi_boot_table_init(void)
{
- /*
- * Enable ACPI instead of device tree unless
- * - ACPI has been disabled explicitly (acpi=off), or
- * - the device tree is not empty (it has more than just a /chosen node)
- * and ACPI has not been force enabled (acpi=force)
- */
- if (param_acpi_off ||
- (!param_acpi_force && of_scan_flat_dt(dt_scan_depth1_nodes, NULL)))
+ if (acpi_disabled)
return;
/*
- * ACPI is disabled at this point. Enable it in order to parse
- * the ACPI tables and carry out sanity checks
- */
- enable_acpi();
-
- /*
* If ACPI tables are initialized and FADT sanity checks passed,
* leave ACPI enabled and carry on booting; otherwise disable ACPI
* on initialization error.
--
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