x86: acpi: Don't touch ACPI hardware in write_acpi_tables()

[oweals/u-boot.git] / arch / x86 / cpu / cpu.c

diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c
index d08b7d9b1e0f05c5642aa6c888ba3772eb7fd1da..290ee084e5e9ac7726c1115e3ffd84390bd95aeb 100644 (file)
--- a/arch/x86/cpu/cpu.c
+++ b/arch/x86/cpu/cpu.c
@@ -179,17 +179,32 @@ __weak void board_final_cleanup(void)
 
 int last_stage_init(void)
 {
+       struct acpi_fadt __maybe_unused *fadt;
+
        board_final_cleanup();
 
-#if CONFIG_HAVE_ACPI_RESUME
-       struct acpi_fadt *fadt = acpi_find_fadt();
+#ifdef CONFIG_HAVE_ACPI_RESUME
+       fadt = acpi_find_fadt();
 
-       if (fadt != NULL && gd->arch.prev_sleep_state == ACPI_S3)
+       if (fadt && gd->arch.prev_sleep_state == ACPI_S3)
                acpi_resume(fadt);
 #endif
 
        write_tables();
 
+#ifdef CONFIG_GENERATE_ACPI_TABLE
+       fadt = acpi_find_fadt();
+
+       /* Don't touch ACPI hardware on HW reduced platforms */
+       if (fadt && !(fadt->flags & ACPI_FADT_HW_REDUCED_ACPI)) {
+               /*
+                * Other than waiting for OSPM to request us to switch to ACPI
+                * mode, do it by ourselves, since SMI will not be triggered.
+                */
+               enter_acpi_mode(fadt->pm1a_cnt_blk);
+       }
+#endif
+
        return 0;
 }
 #endif