Re: [PATCH 2/2] usb: gadget: f_ecm: do not notify from ecm_set_alt()

[sashiko-bot@kernel.org]

> From: Massimo Toscanelli <massimo.toscanelli@leica-geosystems.com>
> 
> ecm_set_alt() calls ecm_notify() for both altsettings of the data
> interface. So a notification is already queued at SET_CONFIGURATION,
> when altsetting 0 is selected, and it waits until the host reads the
> interrupt endpoint.
> 
> The USB 2.0 LPM ECN (section 2.2.2) lets a device answer NYET to an LPM
> request when it has data pending for the host, and DWC3 does so. So
> when the host loads no class driver, the device never enters L1.
> 
> For altsetting 1 the call is not needed: gether_connect() already
> calls ecm_open() or ecm_close(), and both notify. The extra call only
> restarts the sequence while the first notification is in flight, so
> the host gets two connection notifications before the speed one. The
> removed comment calls this a minor disagreement with the ECM spec.
> 
> Remove the call and the comment.
> 
> Fixes: da741b8c56d6 ("usb ethernet gadget: split CDC Ethernet function")
> Signed-off-by: Massimo Toscanelli <massimo.toscanelli@leica-geosystems.com>

Sashiko has reviewed this patch and found no issues.

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Sashiko AI review · https://sashiko.dev/#/patchset/20261023-ncm-ecm-lpm-v1-0-d01e81fbf460@leica-geosystems.com?part=2