On Mon, Jan 20, 2025 at 04:47:02PM +0530, Prashanth K wrote: > Currently CONFIG_USB_GADGET_VBUS_DRAW limits the maximum current > drawn from Vbus to be up to 500mA. However USB gadget operating > in SuperSpeed or higher can draw up to 900mA. Also, MaxPower in > ConfigFS takes its default value from this config. Hence increase > the allowed range of CONFIG_USB_GADGET_VBUS_DRAW to 900mA. Is this the sort of thing that really needs to be a Kconfig option? Why not make the decision at runtime, based on the needs of the gadget or function drivers and the connection speed? Alan Stern > Signed-off-by: Prashanth K <prashanth.k@xxxxxxxxxxxxxxxx> > --- > drivers/usb/gadget/Kconfig | 11 +++++++---- > 1 file changed, 7 insertions(+), 4 deletions(-) > > diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig > index 76521555e3c1..904652c37385 100644 > --- a/drivers/usb/gadget/Kconfig > +++ b/drivers/usb/gadget/Kconfig > @@ -97,8 +97,8 @@ config USB_GADGET_DEBUG_FS > to conserve kernel memory, say "N". > > config USB_GADGET_VBUS_DRAW > - int "Maximum VBUS Power usage (2-500 mA)" > - range 2 500 > + int "Maximum VBUS Power usage (2-900 mA)" > + range 2 900 > default 2 > help > Some devices need to draw power from USB when they are > @@ -107,8 +107,11 @@ config USB_GADGET_VBUS_DRAW > such as an AC adapter or batteries. > > Enter the maximum power your device draws through USB, in > - milliAmperes. The permitted range of values is 2 - 500 mA; > - 0 mA would be legal, but can make some hosts misbehave. > + milliAmperes. The permitted range of values depends on the > + connection speed, for SuperSpeed and higher it's 2 - 900 mA, > + but connections with High-Speed or slower can draw power > + ranging from 2 - 500 mA; 0 mA would be legal, but can make > + some hosts misbehave. > > This value will be used except for system-specific gadget > drivers that have more specific information. > -- > 2.25.1 > >
