Hey folks, I'd welcome some feedback on this, before we're forced to withdraw our software product from general sale. Yes, today is a bad day. :(
We produce a retail s/w application that provides support for a USB HD H.264 video compressor device. It works well on OSX 10.7/8/9 on multiple systems including older Mac Pros, MBP's, MBA's etc. Its not working well on all the 10.10 based Macs we have, namely a iMac 5K and a MBP 13" retina, both (probably) using usb3 controllers, older machines above are probably USB2 controllers. We have customers in the field reporting the same issue "Used to work great, upgraded to 10.10 now it hangs". The USB2.0 device we're controlling has always ran (overbudget) at around 560ma during peak use, idling around 420ma. (Same power measurements under windows also). We have no issues with the device when its running around 420ma on 10.10, although the video compressor is not running at this point, we're doing basic status calls. The behavior we see under 10.10 is that when the device starts to compress video, and the power starts to peak, climbing to 530ma and potentially beyond, we start to see our urbs timing out, the device stops responsing to AsyncBulkAsync reads. Rarely does an urb complete without error, and if it does it's marked as overrun. The important point to note is that the device never gets to 560ma. I've noticed on the Macs running 10.10 that the current never seems to go beyond 530, suggesting some kind of operating system USB current limit, or physical USB3 port current limit that doesn't occur on slightly older systems (or on 10.9). Looking at the usb analyzer we see no protocol issues, only timeouts waiting for posted urbs to be filled. No resets, not failed controll transfers, no visible errors other than timeouts. I should point out that the application works very well with other USB Capture devices on 10.10, all of which run at less than 500ma, I'm confident the application is fine. Are their any known differences between 10.9 and 10.10 with regards to allowable current that can be drawn from either a USB2 or USB3 port? I realize the device runs overbudget, but is the OS (or USB controllers) starting to enforce 500ma limits - that we're only just seeing? Many thanks, - Steve -- Steven Toth - Kernel Labs http://www.kernellabs.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Usb mailing list ([email protected]) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/usb/archive%40mail-archive.com This email sent to [email protected]
