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Commit 332960bd authored by Vikram Pandita's avatar Vikram Pandita Committed by Greg Kroah-Hartman
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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: default avatarVikram Pandita <vikram.pandita@ti.com>
Reviewed-by: default avatarMarek Vasut <marek.vasut@gmail.com>
Signed-off-by: default avatarVikram Pandita <vikram.pandita@ti.com>
Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 4b6181ca

drivers/usb/host/ehci-q.c

+11 −0
Original line number Original line Diff line number Diff line
@@ -373,6 +373,17 @@ qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh) 
 retry_xacterr:

 retry_xacterr:

		if ((token & QTD_STS_ACTIVE) == 0) {

		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

			/* on STALL, error, and short reads this urb must

			 * complete and all its qtds must be recycled.

			 * complete and all its qtds must be recycled.

			 */

			 */