From: Paul Zimmerman Date: Sat, 12 Feb 2011 22:07:57 +0000 (-0800) Subject: xhci: Fix an error in count_sg_trbs_needed() X-Git-Tag: v2.6.37.3~42 X-Git-Url: https://git.fsl.cs.sunysb.edu/?a=commitdiff_plain;h=929364a96776f45edc9b1d71680bf87852dfc39b;p=unionfs-2.6.39.y.git xhci: Fix an error in count_sg_trbs_needed() commit bcd2fde05341cef0052e49566ec88b406a521cf3 upstream. 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 Signed-off-by: Sarah Sharp Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 11d7999db25..09bb3c99083 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -2380,7 +2380,7 @@ 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; }