kconfig: loop as long as we changed some symbols in randconfig

Because of choice-in-a-choice constructs, it can happen that not all
symbols are assigned a value during randconfig, leading in rare cases
to this situation:

    ---8<--- choice-in-choice.in
    choice
        bool "A/B/C"
    config A
        bool "A"

    config B
        bool "B"
    if B
    choice
        bool "E/F"
    config E
        bool "E"
    config F
        bool "F"
    endchoice
    endif # B

    config C
        bool "C"
    endchoice
    ---8<---

    $ ./scripts/kconfig/conf --randconfig choice-in-choice.in
    [--SNIP--]
    $ ./scripts/kconfig/conf --silentoldconfig choice-in-choice.in </dev/null
    [--SNIP--]
    A/B/C
      1. A (A)
    > 2. B (B)
      3. C (C)
    choice[1-3]: 2
      E/F
      > 1. E (E) (NEW)
        2. F (F) (NEW)
      choice[1-2]: aborted!

    Console input/output is redirected. Run 'make oldconfig' to update
    configuration.

Fix this by looping in randconfig for as long as some symbol gets assigned
a value.

Note: this was spotted with the USB EHCI Debug Device Gadget (USB_G_DBGP),
which uses this choice-in-a-choice construct, and exhibits this problem.
The example above is just a stripped-down minimalist test-case.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

1 files changed, 2 insertions, 1 deletions

diff --git a/scripts/kconfig/conf.c b/scripts/kconfig/conf.c
index 38616c14c071..d19944f9c3ac 100644
--- a/scripts/kconfig/conf.c
+++ b/scripts/kconfig/conf.c
@@ -654,7 +654,8 @@ int main(int ac, char **av)
                 conf_set_all_new_symbols(def_default);
                 break;
         case randconfig:
-                conf_set_all_new_symbols(def_random);
+                /* Really nothing to do in this loop */
+                while (conf_set_all_new_symbols(def_random)) ;
                 break;
         case defconfig:
                 conf_set_all_new_symbols(def_default);