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| author | Aleksey Makarov <aleksey.makarov@linaro.org> | 2016-09-27 23:54:13 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-09-28 17:46:46 +0200 |
| commit | ad1696f6f09daacfdf2bf04bc83cd8f48d80e34a (patch) | |
| tree | 5621bb984dfcd615ce17180fd00f08d8163eb756 /include/linux/serial_core.h | |
| parent | d503187b6cc4e41c21c02e695e0e7b5acdd066de (diff) | |
| download | lwn-ad1696f6f09daacfdf2bf04bc83cd8f48d80e34a.tar.gz lwn-ad1696f6f09daacfdf2bf04bc83cd8f48d80e34a.zip | |
ACPI: parse SPCR and enable matching console
'ARM Server Base Boot Requiremets' [1] mentions SPCR (Serial Port
Console Redirection Table) [2] as a mandatory ACPI table that
specifies the configuration of serial console.
Defer initialization of DT earlycon until ACPI/DT decision is made.
Parse the ACPI SPCR table, setup earlycon if required,
enable specified console.
Thanks to Peter Hurley for explaining how this should work.
[1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.den0044a/index.html
[2] https://msdn.microsoft.com/en-us/library/windows/hardware/dn639132(v=vs.85).aspx
Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Tested-by: Christopher Covington <cov@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux/serial_core.h')
| -rw-r--r-- | include/linux/serial_core.h | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index 378d80a8dd43..344201437017 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -367,11 +367,18 @@ extern const struct earlycon_id __earlycon_table_end[]; #define EARLYCON_DECLARE(_name, fn) OF_EARLYCON_DECLARE(_name, "", fn) -extern int setup_earlycon(char *buf); extern int of_setup_earlycon(const struct earlycon_id *match, unsigned long node, const char *options); +#ifdef CONFIG_SERIAL_EARLYCON +extern bool earlycon_init_is_deferred __initdata; +int setup_earlycon(char *buf); +#else +static const bool earlycon_init_is_deferred; +static inline int setup_earlycon(char *buf) { return 0; } +#endif + struct uart_port *uart_get_console(struct uart_port *ports, int nr, struct console *c); int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr, |