From 3fce12568a5c38fe0361b433902a1321d34f93d7 Mon Sep 17 00:00:00 2001 From: Christian Lamparter Date: Fri, 3 Aug 2018 23:49:22 +0200 Subject: [PATCH] kernel: modules: fix kmod-regmap redux Jonas Gorski commented on the previous patch: |This is actually the wrong fix and papers over an issue in one of our |local patches. | |We intentionally allow regmap to be built as a module, see | |/target/linux/generic/hack-4.14/259-regmap_dynamic.patch |[...] |[The regulator code] optionally supports regmap thanks to the stubs |provided if regmap is disabled - which breaks if you compile regmap |as a module. In order to mitigate this issue, this patch reverts the previous patch and replaces the existing IS_ENABLED(CONFIG_REGMAP) with IS_REACHABLE(CONFIG_REGMAP). This solves this particular issue as the regulator code will now automatically fallback to the regmap stubs in case the kmod-regmap module is enabled, but nothing else sets CONFIG_REGMAP=y. Note: There's still a potential issue that this patch doesn't solve: If someone ever wants to make a OpenWrt kernel package for a regulator module that requires the REGMAP feature for a target that doesn't set CONFIG_REGMAP=y but has CONFIG_REGULATOR=y, the resulting kmod-regulator-xyz package will not work on the target. Luckily, there aren't any in-tree OpenWrt kernel module packages for regulators at the moment. On the bright side: regmap is a critical part nowadays and all new and upcoming architectures require it by default. This will likely only ever be a problem for legacy targets and devices that cannot afford to enable REGMAP. Cc: Jonas Gorski Cc: John Crispin Fixes: d00913d1215b ("kernel: modules: fix kmod-regmap") Signed-off-by: Christian Lamparter --- package/kernel/linux/modules/other.mk | 2 +- target/linux/generic/hack-4.14/259-regmap_dynamic.patch | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/package/kernel/linux/modules/other.mk b/package/kernel/linux/modules/other.mk index dd037cf86c..7e18a21db3 100644 --- a/package/kernel/linux/modules/other.mk +++ b/package/kernel/linux/modules/other.mk @@ -718,7 +718,7 @@ define KernelPackage/regmap SUBMENU:=$(OTHER_MENU) TITLE:=Generic register map support DEPENDS:=+kmod-lib-lzo +kmod-i2c-core - KCONFIG:=CONFIG_REGMAP=y \ + KCONFIG:=CONFIG_REGMAP \ CONFIG_REGMAP_MMIO \ CONFIG_REGMAP_SPI \ CONFIG_REGMAP_I2C \ diff --git a/target/linux/generic/hack-4.14/259-regmap_dynamic.patch b/target/linux/generic/hack-4.14/259-regmap_dynamic.patch index 1c6e78df30..458b7c35a1 100644 --- a/target/linux/generic/hack-4.14/259-regmap_dynamic.patch +++ b/target/linux/generic/hack-4.14/259-regmap_dynamic.patch @@ -103,7 +103,7 @@ Signed-off-by: Felix Fietkau }) -#ifdef CONFIG_REGMAP -+#if IS_ENABLED(CONFIG_REGMAP) ++#if IS_REACHABLE(CONFIG_REGMAP) enum regmap_endian { /* Unspecified -> 0 -> Backwards compatible default */