From: Vikram Pandita <[email protected]> Data Buffer Error as per spec section 4.15.1.1.2 results when there is Underrun or Overrun condition.
This error is considered non-fatal and never gets reported. Its a very good indication on things going wrong at system level, like running memory at much slower speed. This is a good error to flag allowing system level corrections. An issue was found with OMAP4460 board where DDR had to be run at full speed and this logging helped. Signed-off-by: Vikram Pandita <[email protected]> --- drivers/usb/host/ehci-q.c | 14 ++++++++++++++ 1 files changed, 14 insertions(+), 0 deletions(-) diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c index 4e4066c..2451361 100644 --- a/drivers/usb/host/ehci-q.c +++ b/drivers/usb/host/ehci-q.c @@ -373,6 +373,20 @@ qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh) retry_xacterr: if ((token & QTD_STS_ACTIVE) == 0) { + /* Report Data Buffer Error: non-fatal but useful */ + if (token & QTD_STS_DBE) { + + ehci_dbg(ehci, + "detected DataBufferErr %s for urb %p ep%d%s len %d, qtd %p [qh %p]\n", + (urb->ep->desc.bEndpointAddress & USB_DIR_IN) ? + "OVER-RUN" : "UNDER-RUN", + urb, urb->ep->desc.bEndpointAddress & 0x0f, + (urb->ep->desc.bEndpointAddress & USB_DIR_IN) ? "in" : "out", + urb->transfer_buffer_length, + qtd, urb->ep->hcpriv); + + } + /* on STALL, error, and short reads this urb must * complete and all its qtds must be recycled. */ -- 1.7.5.4 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
