Hi Wayne,
Our setup is such that we are powering the WiFi card externally. I found the below in the device tree binding documentation.
MMC power
---------
Controllers may implement power control from both the connected cards and
the IO signaling (for example to change to high-speed 1.8V signalling). If
the system supports this, then the following two properties should point
to valid regulator nodes:
- vqmmc-supply: supply node for IO line power
- vmmc-supply: supply node for card's power
Because the card is powered externally, I changed added the property nvidia,vmmc-always-on to the sdhci2 node. But tegra210-porg-power-tree-p3448-0000-a00.dtsi sets vmmc-supply = <&p3448_vdd_3v3_sys>. Is there a need to put a dummy regulator here because the card is power externally?
I also removed vqmmc-supply = <&max77620_ldo6> from an override in tegra210-porg-plugin-manager.dtsi and added vqmcc-supply = <&max77620_sd3> in the sdhci2 node.
The max77620_sd3 is 1.8v regulator.
After these changes, the mmc1 logs no longer show the mmc_rescan_try_freq go into an endless loop. But I do not see an init message for the WiFi card like you mentioned in you post here: WiFi bring up on custom carrier board - #12 by WayneWWW
Loading the driver manually, the mlan0 interface for the WiFi module also isn’t shown.
I am attaching the latest .dtb converted to .dts and the kernel bootlog here.
jul15th_wifi_on_sdio_10.txt (56.1 KB)
jul15th_10.dts (284.5 KB)