From: Paul Zimmerman <Paul.Zimmerman@xxxxxxxxxxxx> The expression while (running_total < sg_dma_len(sg)) does not take into account that the remaining data length can be less than sg_dma_len(sg). In that case, running_total can end up being greater than the total data length, so an extra TRB is counted. Changing the expression to while (running_total < sg_dma_len(sg) && running_total < temp) fixes that. This patch should be queued for stable kernels back to 2.6.31. Signed-off-by: Paul Zimmerman <paulz@xxxxxxxxxxxx> Signed-off-by: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx> Cc: stable@xxxxxxxxxx --- drivers/usb/host/xhci-ring.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index dbbeec9..3289bf4 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -2374,7 +2374,7 @@ static unsigned int count_sg_trbs_needed(struct xhci_hcd *xhci, struct urb *urb) num_trbs++; /* How many more 64KB chunks to transfer, how many more TRBs? */ - while (running_total < sg_dma_len(sg)) { + while (running_total < sg_dma_len(sg) && running_total < temp) { num_trbs++; running_total += TRB_MAX_BUFF_SIZE; } -- 1.6.3.3 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html