patch "xhci: Fix false warning message about wrong bounce buffer write" added to usb-linus

patch "xhci: Fix false warning message about wrong bounce buffer write" added to usb-linus

[gregkh]

This is a note to let you know that I've just added the patch titled

    xhci: Fix false warning message about wrong bounce buffer write

to my usb git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.

If you have any questions about this process, please let me know.


From c03101ff4f74bb30679c1a03d551ecbef1024bf6 Mon Sep 17 00:00:00 2001
From: Mathias Nyman <mathias.nyman@linux.intel.com>
Date: Fri, 4 Oct 2019 14:59:26 +0300
Subject: xhci: Fix false warning message about wrong bounce buffer write
 length

The check printing out the "WARN Wrong bounce buffer write length:"
uses incorrect values when comparing bytes written from scatterlist
to bounce buffer. Actual copied lengths are fine.

The used seg->bounce_len will be set to equal new_buf_len a few lines later
in the code, but is incorrect when doing the comparison.

The patch which added this false warning was backported to 4.8+ kernels
so this should be backported as far as well.

Cc: <stable@vger.kernel.org> # v4.8+
Fixes: 597c56e372da ("xhci: update bounce buffer with correct sg num")
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/1570190373-30684-2-git-send-email-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/usb/host/xhci-ring.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 9741cdeea9d7..85ceb43e3405 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -3202,10 +3202,10 @@ static int xhci_align_td(struct xhci_hcd *xhci, struct urb *urb, u32 enqd_len,
 	if (usb_urb_dir_out(urb)) {
 		len = sg_pcopy_to_buffer(urb->sg, urb->num_sgs,
 				   seg->bounce_buf, new_buff_len, enqd_len);
-		if (len != seg->bounce_len)
+		if (len != new_buff_len)
 			xhci_warn(xhci,
 				"WARN Wrong bounce buffer write length: %zu != %d\n",
-				len, seg->bounce_len);
+				len, new_buff_len);
 		seg->bounce_dma = dma_map_single(dev, seg->bounce_buf,
 						 max_pkt, DMA_TO_DEVICE);
 	} else {
-- 
2.23.0