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: u-boot@lists.denx.de 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?
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