Re: [PATCH v2 2/2] soc: rockchip: Fix compile-testing SoC drivers

From: Robin Murphy
Date: Mon Apr 25 2022 - 14:10:07 EST

On 2022-04-25 18:17, Brian Norris wrote:
Similar to commit 7f94b69ece51 ("ARM: ixp4xx: fix compile-testing soc

drivers/soc/rockchip/Kconfig makes plenty of provision for configuring
drivers either for ARCH_ROCKCHIP or for COMPILE_TEST. But
drivers/soc/Makefile pulls the rug out from under us, by refusing to
build anything if we specified COMPILE_TEST but not ARCH_ROCKCHIP.

Currently, I'm not aware of anything that breaks without this patch, but
it certainly makes for confusing builds (CONFIG_ROCKCHIP_PM_DOMAINS=y,
but we didn't actually compile the driver?) and leaves room for future
error (I have pending patches that break confusingly with COMPILE_TEST=y
even though their Kconfig dependencies seem correct [1]).

Defer to drivers/soc/rockchip/{Makefile,Kconfig} to do the right thing.

We also need to force ARM/ARM64 dependencies for ROCKCHIP_PM_DOMAINS,
because it uses ARM-specific macros (dsb()).

FWIW, those dsb()s could be replaced with generic wmb()s, assuming their purpose is to complete the previous write before polling for the result (TBH it's questionable whether that serves any practical purpose given the ordering rules for Device memory, but I doubt these are critical performance bottlenecks so there doesn't seem to be any real harm in being super-conservative). At worst they could be swapped for generic mb() with no functional change at all, but it seems even harder to justify why that might need to be.


[1] e.g.,
[RFC PATCH 2/2] PM / devfreq: rk3399_dmc: Block PMU during transitions

Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>

Changes in v2:
* Depend on ARM||ARM64

drivers/soc/Makefile | 2 +-
drivers/soc/rockchip/Kconfig | 1 +
2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
index fd7717d597fc..4c91705a8bb3 100644
--- a/drivers/soc/Makefile
+++ b/drivers/soc/Makefile
@@ -23,7 +23,7 @@ obj-y += pxa/
obj-y += amlogic/
obj-y += qcom/
obj-y += renesas/
-obj-$(CONFIG_ARCH_ROCKCHIP) += rockchip/
+obj-y += rockchip/
obj-$(CONFIG_SOC_SAMSUNG) += samsung/
obj-$(CONFIG_SOC_SIFIVE) += sifive/
obj-y += sunxi/
diff --git a/drivers/soc/rockchip/Kconfig b/drivers/soc/rockchip/Kconfig
index aff2f7e95237..785e1798d286 100644
--- a/drivers/soc/rockchip/Kconfig
+++ b/drivers/soc/rockchip/Kconfig
@@ -25,6 +25,7 @@ config ROCKCHIP_IODOMAIN
bool "Rockchip generic power domain"
depends on PM
+ depends on ARM || ARM64
Say y here to enable power domain support.