[PATCH v2 0/8] Make deferring probe forever optional

From: Rob Herring
Date: Thu May 24 2018 - 12:57:58 EST


This series came out of a discussion on the ARM boot-architecture
list[1] about DT forwards and backwards compatibility issues. There are
issues with newer DTs breaking on older, stable kernels. Some of these
are difficult to solve, but cases of optional devices not having
kernel support should be solvable.

I tested this on a RPi3 B with the pinctrl driver forced off. With this
change, the MMC/SD and UART drivers can function without the pinctrl
driver.

v2:
- Add a DT property for pinctrl to flag using defaults
- Add a debug timeout to stop deferring some number of seconds after
initcalls are done (giving modules a chance to load)
- Split pinctrl support to its own patch
- WARN when we stop deferring probe for a device
- Add IOMMU support
- Add PM domain support

Rob

[1] https://lists.linaro.org/pipermail/boot-architecture/2018-April/000466.html


Rob Herring (8):
driver core: make deferring probe after init optional
driver core: add a deferred probe timeout
dt-bindings: pinctrl: add a 'pinctrl-use-default' property
arm: dts: bcm283x: mark the UART pin muxing nodes with
pinctrl-use-default
pinctrl: optionally stop deferring probe at end of initcalls
iommu: Stop deferring probe at end of initcalls
iommu: Remove IOMMU_OF_DECLARE
PM / Domains: Stop deferring probe at the end of initcall

.../admin-guide/kernel-parameters.txt | 7 +++
.../bindings/pinctrl/pinctrl-bindings.txt | 6 +++
arch/arm/boot/dts/bcm283x.dtsi | 2 +
drivers/base/dd.c | 43 +++++++++++++++++++
drivers/base/power/domain.c | 2 +-
drivers/iommu/arm-smmu-v3.c | 2 -
drivers/iommu/arm-smmu.c | 7 ---
drivers/iommu/exynos-iommu.c | 2 -
drivers/iommu/ipmmu-vmsa.c | 3 --
drivers/iommu/msm_iommu.c | 2 -
drivers/iommu/of_iommu.c | 21 +--------
drivers/iommu/qcom_iommu.c | 2 -
drivers/iommu/rockchip-iommu.c | 2 -
drivers/pinctrl/devicetree.c | 14 ++++--
include/linux/device.h | 2 +
include/linux/of_iommu.h | 4 --
16 files changed, 73 insertions(+), 48 deletions(-)

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2.17.0