[PATCH 2/5] edison: Widen the DFU auto-probe window for flashing U-Boot

[Andy Shevchenko]

On Sun, Jun 07, 2026 at 05:05:11PM -0600, Simon Glass wrote:
> On boot the Edison environment opens a brief DFU window (do_probe_dfu) so
> a host can reflash U-Boot over USB before the board continues booting.
> The length of that window is governed by dfu_to_sec, which is 3 seconds.
> 
> Three seconds is not enough, but not because the transfer is slow. The
> window is a hard deadline measured from when do_probe_dfu starts: the dfu
> command records its start time once and never resets it on activity,
> despite the 'inactivity timeout' wording in the command's help. Sending
> U-Boot through the lab uses most of the window before the transfer even
> begins -- the gadget must enumerate, labgrid must detect the resource,
> sync the image and launch dfu-util over SSH, about 3 seconds of setup.
> The 700KB transfer itself takes only about 1.3 seconds (including the
> eMMC write), so the real window usage is roughly 4.4 seconds; a 3-second
> window expires during the setup, before the write can finish.
> 
> Raise dfu_to_sec to 8 to cover the setup and transfer with margin. The
> board waits out this timeout on every boot where no host connects, so
> there is no benefit in making it longer than necessary.

No objection.
Reviewed-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com>

-- 
With Best Regards,
Andy Shevchenko