Hi All,
I have implemented a USB Host driver for a Real Time Operating System and also added support for CPPI DMA. Without CPPI DMA everything works fabulously. But when I enable CPPI DMA capability it works for some devices and fails for others. The issue I see on the bus is that the Data Toggle sometimes does not work for OUT endpoints. When I try to ensure that the data toggle is correct before every transaction my devices work but hub operation fails. I have seen on a forum that a similar issue is present on AM1808 processor as well (http://e2e.ti.com/support/arm/sitara_arm/f/791/p/155414/1083640.aspx#1083640). On some post it has suggested that the DMA support is unstable and in some later posts it says that a workaround is implemented in which data toggle is corrected somehow and RX is placed in transparent mode. I want to ask that is the issue also present on omapl138 platform since Am1808 is almost binary compatible with this? and What is the validity of the workaround for this platform? Thank You.
Regards,
Mughees Ahmed Chohan