From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Hawkins Date: Thu, 26 Jul 2012 11:43:45 -0700 Subject: [U-Boot] bdi3000 configurtio file for mpc8308RDB In-Reply-To: <20120726181741.35FDB203A89@gemini.denx.de> References: <20120726163704.77DC7203A89@gemini.denx.de> <501178EA.6050701@ovro.caltech.edu> <20120726181741.35FDB203A89@gemini.denx.de> Message-ID: <50118FE1.2000806@ovro.caltech.edu> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Wolfgang, >> Grazing through the MPC8308 errata, there don't appear to be any >> major 'gotchas' with this part. ... > > ... not unless you try to use USB device mode. Ah, that is a gotcha then. >> Has anyone had any bad experiences with this part, or is there >> some 'feature' of the part I should be aware of? > > USB device mode doesn't work reliably, and FSL was never able or > willing to come up with a solution. When this issue happens, the USB > device controller not only returns a truncated packet to the gadget > driver, but doesn't report URB completion to the host either. The > host never gets an URB complete event, so you will see first a delay, > and then the host resets the device. The issue can be reproduced with > massive writes to a mass-storage device. The CPCI-S.0 specification defines USB, Ethernet, and PCIe over the backplane. We're going to use Ethernet for monitor/control traffic, and PCIe for data transfers. I had planned on using the PowerPC USB interface to implement at least some form of 'USB device' communication with the board, eg., something like USB-to-Serial or CDC class. In your opinion, is MPC8308 USB Device Mode completely broken? If that is the case, then if I want a UART over CPCI-S.0 USB, I can use an FTDI FT245/FT232 on the CPCI-S.0 USB interface and wire it into either a PowerPC UART or the system control FPGA. How about USB Host mode? The board will communicate with a rear transition module (another board plugged in from the rear side of the chassis). If MPC8308 USB Host Mode is reliable, then I can wire the USB interface through the backplane for use on the RTM, eg., for talking to an FT245/232 device or a USB microcontroller. Thanks for the valuable feedback. Cheers, Dave