Re: [PATCH] bus: mhi: host: Add sysfs entry to force device to enter EDL

From: Jeffrey Hugo
Date: Tue Jan 02 2024 - 10:31:36 EST


On 12/25/2023 12:47 AM, Qiang Yu wrote:
From: Bhaumik Bhatt <quic_bbhatt@xxxxxxxxxxx>

Forcing the device (eg. SDX75) to enter Emergency Download Mode involves
writing the 0xEDEDEDED cookie to the channel 91 doorbell register and
forcing an SOC reset afterwards. Allow users of the MHI bus to exercise the
sequence using a sysfs entry.

I don't see this documented in the spec anywhere. Is this standard behavior for all MHI devices?

What about devices that don't support EDL mode?

How should the host avoid using this special cookie when EDL mode is not desired?

-Jeff