[PATCH] bootchooser: add new value "reset" to reset boot attempts counter

[Holger Assmann <h.assmann@xxxxxxxxxxxxxx>]

bootchooser provides a mechanism that allows for resetting the
"remaining_attempts" counters of all enabled boot slots to their
defaults.

The current possible trigger values to be stored in the defining
variable $bootchooser.reset_attempts are "all-zero" (i.e. no attempts
left at any boot slot) and "power-on" (i.e. $global.system.reset="POR").

We now want to add the option "reset" (i.e. $global.system.reset="RST")
to that list, so that we do not have to perform an entire power cycle
every time we need a counter reset.

By introducing the "reset" value as an option, we can deliberately cause
the bootchooser to set the "remaining_attempts" values to their defaults
when performing a generic restart. The restart handler of the main OS
is hence responsible that the subsequent barebox run sees "RESET_RST" as
reset reason instead of e.g. "RESET_WDG".

Signed-off-by: Holger Assmann <h.assmann@xxxxxxxxxxxxxx>
---
 Documentation/user/bootchooser.rst |  6 ++++++
 common/bootchooser.c               | 11 +++++++++++
 2 files changed, 17 insertions(+)

diff --git a/Documentation/user/bootchooser.rst b/Documentation/user/bootchooser.rst
index db0a4f8898..1a2ce70bb2 100644
--- a/Documentation/user/bootchooser.rst
+++ b/Documentation/user/bootchooser.rst
@@ -92,6 +92,12 @@ list of space-separated flags. Possible values are:
   (``$global.system.reset="POR"``) is detected, the ``remaining_attempts``
   counters of all enabled targets are reset to their defaults.
   This means after a power cycle all boot targets will be tried again for the configured number of retries.
+- ``reset``: When the bootchooser starts and a generic reset
+  (``$global.system.reset="RST"``) is detected, the ``remaining_attempts``
+  counters of all enabled targets are reset to their defaults.
+  This means that, if the systems reports a generic restart, the
+  ``remaining_attempts`` counters of all enabled targets are reset to
+  their defaults.
 - ``all-zero``: When the bootchooser starts and the ``remaining_attempts``
   counters of all enabled targets are zero, the ``remaining_attempts``
   counters of all enabled targets are reset to their defaults.
diff --git a/common/bootchooser.c b/common/bootchooser.c
index eb3dda52ab..022e225165 100644
--- a/common/bootchooser.c
+++ b/common/bootchooser.c
@@ -77,6 +77,7 @@ struct bootchooser_target {
 enum reset_attempts {
 	RESET_ATTEMPTS_POWER_ON,
 	RESET_ATTEMPTS_ALL_ZERO,
+	RESET_ATTEMPTS_SRC_RST,
 };
 
 static unsigned long reset_attempts;
@@ -439,6 +440,13 @@ struct bootchooser *bootchooser_get(void)
 		attempts_resetted = 1;
 	}
 
+	if (test_bit(RESET_ATTEMPTS_SRC_RST, &reset_attempts) &&
+	    reset_source_get() == RESET_RST && !attempts_resetted) {
+		pr_info("RST Reset, resetting remaining attempts\n");
+		bootchooser_reset_attempts(bc);
+		attempts_resetted = 1;
+	}
+
 	if (test_bit(RESET_ATTEMPTS_ALL_ZERO, &reset_attempts)) {
 		int attempts = 0;
 
@@ -915,6 +923,7 @@ static int bootchooser_add_entry(struct bootentries *entries, const char *name)
 static const char * const reset_attempts_names[] = {
 	[RESET_ATTEMPTS_POWER_ON] = "power-on",
 	[RESET_ATTEMPTS_ALL_ZERO] = "all-zero",
+	[RESET_ATTEMPTS_SRC_RST] = "reset",
 };
 
 static const char * const reset_priorities_names[] = {
@@ -951,6 +960,8 @@ BAREBOX_MAGICVAR(global.bootchooser.targets,
 		 "bootchooser: Space separated list of target names");
 BAREBOX_MAGICVAR(global.bootchooser.default_attempts,
 		 "bootchooser: Default number of attempts for a target");
+BAREBOX_MAGICVAR(global.bootchooser.reset_attempts,
+		"bootchooser: Choose condition to reset number of attempts for all enabled targets ('power-on', 'all-zero', 'reset')");
 BAREBOX_MAGICVAR(global.bootchooser.default_priority,
 		 "bootchooser: Default priority for a target");
 BAREBOX_MAGICVAR(global.bootchooser.state_prefix,
-- 
2.39.2