Re: [PATCH 4/4] platform/chrome: i2c: i2c-cros-ec-tunnel: Convert i2c tunnel to MFD Cell

Lee Jones
2019-12-09T13:17:57Z

On Thu, 21 Nov 2019, Raul E Rangel wrote:

> If the i2c-cros-ec-tunnel driver is compiled into the kernel, it is
> possible that i2c-cros-ec-tunnel could be probed before cros_ec_XXX
> has finished initializing and setting the drvdata. This would cause a
> NULL pointer panic.
>
> Converting this driver over to an MFD solves the problem and aligns with
> where the cros_ec is going.
>
> Signed-off-by: Raul E Rangel <rrangel@chromium.org>
> ---
> You can now see the device node lives under the mfd device.
>
> $ find /sys/bus/platform/devices/cros-ec-dev.0.auto/cros-ec-i2c-tunnel.12.auto/ -iname firmware_node -exec ls -l '{}' \;
> /sys/bus/platform/devices/cros-ec-dev.0.auto/cros-ec-i2c-tunnel.12.auto/firmware_node -> ../../../../../../LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:1c/PNP0C09:00/GOOG0004:00/GOOG0012:00
> /sys/bus/platform/devices/cros-ec-dev.0.auto/cros-ec-i2c-tunnel.12.auto/i2c-9/firmware_node -> ../../../../../../../LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:1c/PNP0C09:00/GOOG0004:00/GOOG0012:00
> /sys/bus/platform/devices/cros-ec-dev.0.auto/cros-ec-i2c-tunnel.12.auto/i2c-9/i2c-10EC5682:00/firmware_node -> ../../../../../../../../LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:1c/PNP0C09:00/GOOG0004:00/GOOG0012:00/10EC5682:00
>
> drivers/i2c/busses/i2c-cros-ec-tunnel.c | 36 +++++++++----------------
> drivers/mfd/cros_ec_dev.c | 19 +++++++++++++

For my own reference:
Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org>

--
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
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