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authorPrarit Bhargava <prarit@redhat.com>2018-01-18 10:09:51 -0500
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2018-02-07 11:39:58 +0100
commit0231d00082f61cfe03f2b7c27e5356f8cdf0312c (patch)
tree24f036cb972640ccdeed395a55d1c37571fcb3db /drivers/acpi
parent890674343bb2d546825f713542b1e199f0728732 (diff)
ACPI: SPCR: Make SPCR available to x86
SPCR is currently only enabled or ARM64 and x86 can use SPCR to setup an early console. General fixes include updating Documentation & Kconfig (for x86), updating comments, and changing parse_spcr() to acpi_parse_spcr(), and earlycon_init_is_deferred to earlycon_acpi_spcr_enable to be more descriptive. On x86, many systems have a valid SPCR table but the table version is not 2 so the table version check must be a warning. On ARM64 when the kernel parameter earlycon is used both the early console and console are enabled. On x86, only the earlycon should be enabled by by default. Modify acpi_parse_spcr() to allow options for initializing the early console and console separately. Signed-off-by: Prarit Bhargava <prarit@redhat.com> Acked-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Mark Salter <msalter@redhat.com> Tested-by: Mark Salter <msalter@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/Kconfig7
-rw-r--r--drivers/acpi/spcr.c29
2 files changed, 21 insertions, 15 deletions
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 46505396869e..ddcb5f40e8ee 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -79,7 +79,12 @@ config ACPI_DEBUGGER_USER
endif
config ACPI_SPCR_TABLE
- bool
+ bool "ACPI Serial Port Console Redirection Support"
+ default y if X86
+ help
+ Enable support for Serial Port Console Redirection (SPCR) Table.
+ This table provides information about the configuration of the
+ earlycon console.
config ACPI_LPIT
bool
diff --git a/drivers/acpi/spcr.c b/drivers/acpi/spcr.c
index 324b35bfe781..89e97d21a89c 100644
--- a/drivers/acpi/spcr.c
+++ b/drivers/acpi/spcr.c
@@ -21,7 +21,7 @@
* occasionally getting stuck as 1. To avoid the potential for a hang, check
* TXFE == 0 instead of BUSY == 1. This may not be suitable for all UART
* implementations, so only do so if an affected platform is detected in
- * parse_spcr().
+ * acpi_parse_spcr().
*/
bool qdf2400_e44_present;
EXPORT_SYMBOL(qdf2400_e44_present);
@@ -74,19 +74,21 @@ static bool xgene_8250_erratum_present(struct acpi_table_spcr *tb)
}
/**
- * parse_spcr() - parse ACPI SPCR table and add preferred console
+ * acpi_parse_spcr() - parse ACPI SPCR table and add preferred console
*
- * @earlycon: set up earlycon for the console specified by the table
+ * @enable_earlycon: set up earlycon for the console specified by the table
+ * @enable_console: setup the console specified by the table.
*
* For the architectures with support for ACPI, CONFIG_ACPI_SPCR_TABLE may be
* defined to parse ACPI SPCR table. As a result of the parsing preferred
- * console is registered and if @earlycon is true, earlycon is set up.
+ * console is registered and if @enable_earlycon is true, earlycon is set up.
+ * If @enable_console is true the system console is also configured.
*
* When CONFIG_ACPI_SPCR_TABLE is defined, this function should be called
* from arch initialization code as soon as the DT/ACPI decision is made.
*
*/
-int __init parse_spcr(bool earlycon)
+int __init acpi_parse_spcr(bool enable_earlycon, bool enable_console)
{
static char opts[64];
struct acpi_table_spcr *table;
@@ -105,11 +107,8 @@ int __init parse_spcr(bool earlycon)
if (ACPI_FAILURE(status))
return -ENOENT;
- if (table->header.revision < 2) {
- err = -ENOENT;
- pr_err("wrong table version\n");
- goto done;
- }
+ if (table->header.revision < 2)
+ pr_info("SPCR table version %d\n", table->header.revision);
if (table->serial_port.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
switch (ACPI_ACCESS_BIT_WIDTH((
@@ -185,7 +184,7 @@ int __init parse_spcr(bool earlycon)
*/
if (qdf2400_erratum_44_present(&table->header)) {
qdf2400_e44_present = true;
- if (earlycon)
+ if (enable_earlycon)
uart = "qdf2400_e44";
}
@@ -205,11 +204,13 @@ int __init parse_spcr(bool earlycon)
pr_info("console: %s\n", opts);
- if (earlycon)
+ if (enable_earlycon)
setup_earlycon(opts);
- err = add_preferred_console(uart, 0, opts + strlen(uart) + 1);
-
+ if (enable_console)
+ err = add_preferred_console(uart, 0, opts + strlen(uart) + 1);
+ else
+ err = 0;
done:
acpi_put_table((struct acpi_table_header *)table);
return err;

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