SBBR mentions SPCR as a mandatory ACPI table. So enable it for ARM64 Earlycon should be set up as early as possible. ACPI boot tables are mapped in arch/arm64/kernel/acpi.c:acpi_boot_table_init() that is called from setup_arch() and that's where we parse SPCR. So it has to be opted-in per-arch. When ACPI_SPCR_TABLE is defined initialization of DT earlycon is deferred until the DT/ACPI decision is done. Initialize DT earlycon if ACPI is disabled. Acked-by: Will Deacon <will.deacon@xxxxxxx> Acked-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx> Signed-off-by: Aleksey Makarov <aleksey.makarov@xxxxxxxxxx> Tested-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> Tested-by: Christopher Covington <cov@xxxxxxxxxxxxxx> --- arch/arm64/Kconfig | 1 + arch/arm64/kernel/acpi.c | 11 ++++++++++- 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index bc3f00f..11a2d36 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -4,6 +4,7 @@ config ARM64 select ACPI_GENERIC_GSI if ACPI select ACPI_REDUCED_HARDWARE_ONLY if ACPI select ACPI_MCFG if ACPI + select ACPI_SPCR_TABLE if ACPI select ARCH_HAS_DEVMEM_IS_ALLOWED select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c index 3e4f1a4..252a6d9 100644 --- a/arch/arm64/kernel/acpi.c +++ b/arch/arm64/kernel/acpi.c @@ -24,6 +24,7 @@ #include <linux/memblock.h> #include <linux/of_fdt.h> #include <linux/smp.h> +#include <linux/serial_core.h> #include <asm/cputype.h> #include <asm/cpu_ops.h> @@ -206,7 +207,7 @@ void __init acpi_boot_table_init(void) if (param_acpi_off || (!param_acpi_on && !param_acpi_force && of_scan_flat_dt(dt_scan_depth1_nodes, NULL))) - return; + goto done; /* * ACPI is disabled at this point. Enable it in order to parse @@ -226,6 +227,14 @@ void __init acpi_boot_table_init(void) if (!param_acpi_force) disable_acpi(); } + +done: + if (acpi_disabled) { + if (earlycon_init_is_deferred) + early_init_dt_scan_chosen_stdout(); + } else { + parse_spcr(earlycon_init_is_deferred); + } } #ifdef CONFIG_ACPI_APEI -- 2.10.0 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html