One thing we have come across is that some USB drives require a longer delay between powering up and initialization.
I have historically also run into a lot of problems with both Sandisk USB devices and Sandisk SD cards, finding instances where they do not follow the standards. -Aaron On Thursday, July 27, 2017 1:42:02 PM PDT Sergey Manucharian wrote: > New findings: > > The problem is different, it happens only with USB 3 flash drives, USB 2 > devices are powered properly. I don't have real statistics, but the > newest SanDisk's drives won't work. > > However, it's hard to believe that a tiny USB drive requests more than > 500mA to assume that the controller and/or u-boot decide to not provide > power to it. > > Sergey > > Excerpts from Lokesh Vutla's message from Mon 10-Jul-17 18:47: > > On 7/8/2017 8:50 AM, Sergey Manucharian wrote: > > > (sorry for top posting, sending from a phone) > > > > > > I would agree it's intentional at the first stage: we don't want to > > > power external devices which we may not need, however, the "usb start" > > > command must enable it, otherwise it's useless...> > > Right. Any chance you bisected to the commit which caused the issue? > > > > Thanks and regards, > > Lokesh > > > > > -S. > > > > > > Original Message > > > > > > From: Tom Rini > > > Sent: Friday, July 7, 2017 18:41 > > > To: sm; Lokesh Vutla > > > Cc: [email protected] > > > Subject: Re: [U-Boot] USB power is not enabled fro BeagleBone Black > > > > > > On Sat, Jul 01, 2017 at 12:51:41PM -0700, sm wrote: > > >> Hi all, > > >> > > >> The latest git version does not turn on USB power on BeagleBone Black: > > >> "usb start" reports that the port is not accessible, but with external > > >> power provided it detects the plugged in device. > > > > > > Yes, I think this may be intentional? > > _______________________________________________ > U-Boot mailing list > [email protected] > https://lists.denx.de/listinfo/u-boot -- Aaron Williams Senior Software Engineer Cavium, Inc. (408) 943-7198 (510) 789-8988 (cell) _______________________________________________ U-Boot mailing list [email protected] https://lists.denx.de/listinfo/u-boot
