Hi Prashanth,
On Thu, Feb 23, 2023 at 10:48:30AM +0530, Prashanth K wrote:
> Currently we don't change the current value if device isn't in
> configured state. But the battery charging specification says,
> the device can draw upto 100mA of current if its in unconfigured
Here you say spec says "up to" (BTW you have a typo) 100mA...
> state. Hence add a Vbus_draw work in composite_resume to draw
> 100mA if the device isn't configured.
But here and in the patch you are calling the function to draw exactly
100mA. Consider the possibility that a gadget could be configured to
draw less current than that or not anything at all, we should make sure
to honor that as an absolute maximum.
> Signed-off-by: Prashanth K <quic_prashk@xxxxxxxxxxx>
> ---
> drivers/usb/gadget/composite.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
> index fa7dd6c..147d278 100644
> --- a/drivers/usb/gadget/composite.c
> +++ b/drivers/usb/gadget/composite.c
> @@ -2531,6 +2531,8 @@ void composite_resume(struct usb_gadget *gadget)
> usb_gadget_clear_selfpowered(gadget);
>
> usb_gadget_vbus_draw(gadget, maxpower);
> + } else {
> + usb_gadget_vbus_draw(gadget, 100);
Similar to the configured case, maybe you can perform a min()
calculation against either or both the config->MaxPower or
CONFIG_USB_GADGET_VBUS_DRAW.
Thanks,
Jack
