ACPI: prevent randconfig build failure on empty ACPI_CUSTOM_DSDT_FILE

Make ACPI_CUSTOM_DSDT boolean config symbol a hidden and derived
value, based on the value of ACPI_CUSTOM_DSDT_FILE (string).
Only the latter is presented to the user as a config option.

This fixes problems with "make randconfig" setting ACPI_CUSTOM_DSDT
but leaving ACPI_CUSTOM_DSDT_FILE empty/blank.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 9 insertions, 10 deletions

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index f688c214be0c..fbcaa069be86 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -283,24 +283,23 @@ config ACPI_TOSHIBA
           If you have a legacy free Toshiba laptop (such as the Libretto L1
           series), say Y.
 
-config ACPI_CUSTOM_DSDT
-        bool "Include Custom DSDT"
+config ACPI_CUSTOM_DSDT_FILE
+        string "Custom DSDT Table file to include"
+        default ""
         depends on !STANDALONE
-        default n 
         help
           This option supports a custom DSDT by linking it into the kernel.
           See Documentation/acpi/dsdt-override.txt
 
-          If unsure, say N.
-
-config ACPI_CUSTOM_DSDT_FILE
-        string "Custom DSDT Table file to include"
-        depends on ACPI_CUSTOM_DSDT
-        default ""
-        help
           Enter the full path name to the file which includes the AmlCode
           declaration.
 
+          If unsure, don't enter a file name.
+
+config ACPI_CUSTOM_DSDT
+        bool
+        default ACPI_CUSTOM_DSDT_FILE != ""
+
 config ACPI_CUSTOM_DSDT_INITRD
         bool "Read Custom DSDT from initramfs"
         depends on BLK_DEV_INITRD