[PATCH] usb: xhci: fix Immediate Data Transfer endianness

From: Samuel Holland
Date: Sat Oct 19 2019 - 21:53:24 EST


The arguments to queue_trb are always byteswapped to LE for placement in
the ring, but this should not happen in the case of immediate data; the
bytes copied out of transfer_buffer are already in the correct order.
Add a complementary byteswap so the bytes end up in the ring correctly.

This was observed on BE ppc64 with a "Texas Instruments TUSB73x0
SuperSpeed USB 3.0 xHCI Host Controller [104c:8241]" as a ch341
usb-serial adapter ("1a86:7523 QinHeng Electronics HL-340 USB-Serial
adapter") always transmitting the same character (generally NUL) over
the serial link regardless of the key pressed.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 33e39350ebd2 ("usb: xhci: add Immediate Data Transfer support")
Signed-off-by: Samuel Holland <samuel@xxxxxxxxxxxx>
---
drivers/usb/host/xhci-ring.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 85ceb43e3405..e7aab31fd9a5 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -3330,6 +3330,7 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
if (xhci_urb_suitable_for_idt(urb)) {
memcpy(&send_addr, urb->transfer_buffer,
trb_buff_len);
+ le64_to_cpus(&send_addr);
field |= TRB_IDT;
}
}
@@ -3475,6 +3476,7 @@ int xhci_queue_ctrl_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
if (xhci_urb_suitable_for_idt(urb)) {
memcpy(&addr, urb->transfer_buffer,
urb->transfer_buffer_length);
+ le64_to_cpus(&addr);
field |= TRB_IDT;
} else {
addr = (u64) urb->transfer_dma;
--
2.21.0