On Fri, 18 Jun 2010, Ramya Desai wrote: > Dear All, > > I am working on a UASP driver for a custom device. As a part of this, > I am seeing an issue with multiple streams. When I dig into the xHCI > sources, I saw that the xHCI software is not receiving any interrupt > for a particular data transfer, which is submitted by the xHCI driver. > I checked all the bits for the submitted TRBs like IOC (Interrupt On > Complete), ISP (Interrupt on Short Packet) and Chain bit etc. > > However, according to the xHCI specification, after submitting the TRB > to the xHC, it should generate Interrupt On Completion (IOC) or > Interrupt-On-Short-Packet (ISP) or error occurred while executing a > Transfer TRB through completion callback. But, we are not able to > receive any information from the xHC after submitting the Transfer > TRBs to it. > > Here my questions are, > Why the xHCI sources are not receiving any interrupt? > What are the possible reasons for this? I know extremely little about xHCI, so this probably won't be of much help. However... There's one very obvious reason why you might not get a completion interrupt for your transfer: because the transfer never completes! Have you checked (with a USB bus analyzer) whether the transfer actually took place? Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
