[PATCH v4] driver core: Add CONFIG_FW_DEVLINK_SYNC_STATE_TIMEOUT

[Saravana Kannan <saravanak@google.com>]

Add a build time equivalent of fw_devlink.sync_state=timeout so that
board specific kernels could enable it and not have to deal with setting
or cluttering the kernel commandline.

Cc: Doug Anderson <dianders@chromium.org>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
---
v1 -> v2:
- Removed "default n" and expanded on the help text.
v2 -> v3:
- Added a description for the "bool" so the config can be enabled by the
  user.
v3 -> v4:
- Added this version change history.
- Added Doug's Reviewed-by.

 drivers/base/Kconfig | 12 ++++++++++++
 drivers/base/core.c  |  5 +++++
 2 files changed, 17 insertions(+)

diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index 6f04b831a5c0..2b8fd6bb7da0 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -230,4 +230,16 @@ config GENERIC_ARCH_NUMA
 	  Enable support for generic NUMA implementation. Currently, RISC-V
 	  and ARM64 use it.
 
+config FW_DEVLINK_SYNC_STATE_TIMEOUT
+	bool "sync_state() behavior defaults to timeout instead of strict"
+	help
+	  This is build time equivalent of adding kernel command line parameter
+	  "fw_devlink.sync_state=timeout". Give up waiting on consumers and
+	  call sync_state() on any devices that haven't yet received their
+	  sync_state() calls after deferred_probe_timeout has expired or by
+	  late_initcall() if !CONFIG_MODULES. You should almost always want to
+	  select N here unless you have already successfully tested with the
+	  command line option on every system/board your kernel is expected to
+	  work on.
+
 endmenu
diff --git a/drivers/base/core.c b/drivers/base/core.c
index fe74a786e2c3..adc81871829f 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1672,7 +1672,12 @@ early_param("fw_devlink.strict", fw_devlink_strict_setup);
 #define FW_DEVLINK_SYNC_STATE_STRICT	0
 #define FW_DEVLINK_SYNC_STATE_TIMEOUT	1
 
+#ifndef CONFIG_FW_DEVLINK_SYNC_STATE_TIMEOUT
 static int fw_devlink_sync_state;
+#else
+static int fw_devlink_sync_state = FW_DEVLINK_SYNC_STATE_TIMEOUT;
+#endif
+
 static int __init fw_devlink_sync_state_setup(char *arg)
 {
 	if (!arg)
-- 
2.40.0.rc2.332.ga46443480c-goog