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| author | Vikram Pandita <vikram.pandita@ti.com> | 2011-10-30 20:55:09 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-11-15 01:46:07 +0100 |
| commit | 332960bd7eb48ef21923b4876e7fe3487d6bf11c (patch) | |
| tree | 0f41733ceaa5b21dc369fde8a5e26434b93abb81 /drivers/usb/host/ehci-q.c | |
| parent | USB: serial: cp210x.c: add mark/space parity (diff) | |
| download | linux-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>
Diffstat (limited to 'drivers/usb/host/ehci-q.c')
| -rw-r--r-- | drivers/usb/host/ehci-q.c | 11 |
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. */ |