Re: [PATCH] usb: gadget/legacy/ether: assume saner default power mode

Greg KH
2021-09-16T15:36:37Z

On Thu, Sep 16, 2021 at 09:56:15PM +0700, Andreas Bauer wrote:
>
> I propose the included patch to the OTG USB ethernet gadget code:
>
> Report default of bus powered and 500mA bMaxPower consumption.
>
> Reason:
>
> The USB spec requires all devices consuming more than 100mA from
> the bus to report in this manner. Devices such as Rpi Zero can operate
> in this mode and will then falsly report being self-powered when they
> are not.
>
> The more sane default is to report being 500mA bus-powered than being
> self-powered
>
> This patch was born from an issue within the Raspberry Pi Zero ecosystem,
> therefore I would invite comment regarding other usage of this OTG code.
>
> Best regards,
>
> Andreas
>
> $ diff -u linux-5.14.2/drivers/usb/gadget/legacy/ether.c.orig linux-5.14.2/drivers/usb/gadget/legacy/ether.c
> --- linux-5.14.2/drivers/usb/gadget/legacy/ether.c.orig 2021-09-08 13:52:41.000000000 +0700
> +++ linux-5.14.2/drivers/usb/gadget/legacy/ether.c 2021-09-16 21:25:06.782958554 +0700
> @@ -296,7 +296,8 @@
> /* .label = f(hardware) */
> .bConfigurationValue = 1,
> /* .iConfiguration = DYNAMIC */
> - .bmAttributes = USB_CONFIG_ATT_SELFPOWER,
> + .bmAttributes = 0, /* bus powered implied */
> + .bMaxPower = 250, /* 500mA in 2mA units */
> };
>
> /*-------------------------------------------------------------------------*/

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman. You have sent him
a patch that has triggered this response. He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created. Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
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thanks,

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