On 04/05/2016 07:35 PM, Stephen Warren wrote: > On 04/05/2016 10:36 AM, Semen Protsenko wrote: >> From: Sam Protsenko <semen.protse...@linaro.org> >> >> The description was borrowed from kernel, but allowed range was changed >> from 2..500 to 0..500, because some boards require this option to be 0. > > Do they /require/ the value to be 0, or simply currently have it set to > 0 because whoever set the value in U-Boot wasn't aware that a value of 0 > could cause issues with some hosts? > > I'd be tempted to keep the same range as the Linux kernel and bump all > boards up to a minimum value of 2.
Right. VBUS draw 0 might confuse some non-Linux systems. > Presumably there's some good reason > the kernel chose a minimum of 2, and in practice I expect increasing all > boards to 2 isn't going to make any negative difference. > >> diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig > >> +config USB_GADGET_VBUS_DRAW >> + int "Maximum VBUS Power usage (2-500 mA)" >> + range 0 500 >> + default 2 >> + help >> + Some devices need to draw power from USB when they are >> + configured, perhaps to operate circuitry or to recharge >> + batteries. This is in addition to any local power supply, >> + 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. > > In particular, I'm thinking of that last sentence. -- Best regards, Marek Vasut _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
