From: Vikram Pandita <vikram.pandita@xxxxxx>
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 <vikram.pandita@xxxxxx>
Reviewed-by: Marek Vasut <marek.vasut@xxxxxxxxx>
---
v1: original patch
v2: fix review comments from Alan Stern<stern@xxxxxxxxxxxxxxxxxxx>
drivers/usb/host/ehci-q.c | 10 ++++++++++
1 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c
index 4e4066c..f81c6de 100644
--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -373,6 +373,16 @@ 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 for urb %p ep%d%s len %d, qtd %p [qh %p]\n",
+ urb, usb_endpoint_num(urb->ep),
+ usb_endpoint_dir_in(urb->ep) ? "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
--
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