summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorVikram Pandita <vikram.pandita@ti.com>2011-10-30 20:55:09 +0100
committerGreg Kroah-Hartman <gregkh@suse.de>2011-11-15 01:46:07 +0100
commit332960bd7eb48ef21923b4876e7fe3487d6bf11c (patch)
tree0f41733ceaa5b21dc369fde8a5e26434b93abb81
parentUSB: serial: cp210x.c: add mark/space parity (diff)
downloadlinux-332960bd7eb48ef21923b4876e7fe3487d6bf11c.tar.xz
linux-332960bd7eb48ef21923b4876e7fe3487d6bf11c.zip
USB: ehci: report Data Buffer Error in debug mode
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@ti.com> Reviewed-by: Marek Vasut <marek.vasut@gmail.com> Signed-off-by: Vikram Pandita <vikram.pandita@ti.com> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/usb/host/ehci-q.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c
index 4e4066c35a09..f136f7f1c4f4 100644
--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -373,6 +373,17 @@ 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->desc),
+ usb_endpoint_dir_in(&urb->ep->desc) ? "in" : "out",
+ urb->transfer_buffer_length,
+ qtd,
+ qh);
+
/* on STALL, error, and short reads this urb must
* complete and all its qtds must be recycled.
*/