From: Svyatoslav Ryhel clamor95@gmail.com
[ Upstream commit cca41614d15ce2bbc2c661362d3eafe53c9990af ]
Add missing interrupt to magnetometer node.
Tested-by: Winona Schroeer-Smith wolfizen@wolfizen.net # ASUS SL101 Tested-by: Antoni Aloy Torrens aaloytorrens@gmail.com # ASUS TF101 Signed-off-by: Svyatoslav Ryhel clamor95@gmail.com Signed-off-by: Thierry Reding treding@nvidia.com Signed-off-by: Sasha Levin sashal@kernel.org ---
LLM Generated explanations, may be completely bogus:
YES – wiring the AK8974’s data‑ready interrupt into the TF101 device tree fixes a real functional gap with minimal risk.
- `arch/arm/boot/dts/nvidia/tegra20-asus-tf101.dts:503` gains the missing `interrupt-parent`/`interrupts` pair, finally describing the DRDY line that the hardware routes to GPIO N5; other Tegra20 boards with the same magnetometer already do this (see `arch/arm/boot/dts/nvidia/tegra20-acer-a500-picasso.dts:532`), so the change aligns the TF101 description with established practice. - The AK8974 driver switches to an interrupt-driven path whenever `i2c->irq` is populated (`drivers/iio/magnetometer/ak8974.c:300` through `drivers/iio/magnetometer/ak8974.c:347`); without this property the TF101 falls back to a tight 6 ms polling loop (`drivers/iio/magnetometer/ak8974.c:350`–`361`), which is both power- inefficient and prone to `-ETIMEDOUT` errors under heavier sampling loads—exactly the kind of user-visible malfunction stable trees aim to eliminate. - Because the patch only adds two DT properties, it is completely localized to this board, has no dependency on newer frameworks, keeps the ABI intact, and has already been validated on real ASUS TF101 and SL101 hardware (`Tested-by` tags in the commit). - No conflicting pinmux or GPIO consumers were found in the TF101 tree, so backporting will not disturb other peripherals, and older stable kernels already ship the same driver behaviour—meaning the fix drops in cleanly.
Given the tangible reliability improvement for existing devices, the tiny scope, and demonstrated hardware testing, this is a solid stable backport candidate.
arch/arm/boot/dts/nvidia/tegra20-asus-tf101.dts | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/arch/arm/boot/dts/nvidia/tegra20-asus-tf101.dts b/arch/arm/boot/dts/nvidia/tegra20-asus-tf101.dts index 67764afeb0136..39008816fe5ee 100644 --- a/arch/arm/boot/dts/nvidia/tegra20-asus-tf101.dts +++ b/arch/arm/boot/dts/nvidia/tegra20-asus-tf101.dts @@ -502,6 +502,9 @@ magnetometer@e { compatible = "asahi-kasei,ak8974"; reg = <0xe>;
+ interrupt-parent = <&gpio>; + interrupts = <TEGRA_GPIO(N, 5) IRQ_TYPE_EDGE_RISING>; + avdd-supply = <&vdd_3v3_sys>; dvdd-supply = <&vdd_1v8_sys>;