From: Stephane Grosjean <s.grosjean@xxxxxxxxxxxxxxx>
This patch has been added to the 4.1 stable tree. If you have any
objections, please let us know.
===============
[ Upstream commit d8a243af1a68395e07ac85384a2740d4134c67f4 ]
In some rare conditions when running one PEAK USB-FD interface over
a non high-speed USB controller, one useless USB fragment might be sent.
This patch fixes the way a USB command is fragmented when its length is
greater than 64 bytes and when the underlying USB controller is not a
high-speed one.
Signed-off-by: Stephane Grosjean <s.grosjean@xxxxxxxxxxxxxxx>
Cc: linux-stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
drivers/net/can/usb/peak_usb/pcan_usb_fd.c | 21 +++++++++++----------
1 file changed, 11 insertions(+), 10 deletions(-)
diff --git a/drivers/net/can/usb/peak_usb/pcan_usb_fd.c b/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
index ce44a033f63b..64cc86a82b2d 100644
--- a/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
+++ b/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
@@ -184,7 +184,7 @@ static int pcan_usb_fd_send_cmd(struct peak_usb_device *dev, void *cmd_tail)
void *cmd_head = pcan_usb_fd_cmd_buffer(dev);
int err = 0;
u8 *packet_ptr;
- int i, n = 1, packet_len;
+ int packet_len;
ptrdiff_t cmd_len;
/* usb device unregistered? */
@@ -201,17 +201,13 @@ static int pcan_usb_fd_send_cmd(struct peak_usb_device *dev, void *cmd_tail)
}
packet_ptr = cmd_head;
+ packet_len = cmd_len;
/* firmware is not able to re-assemble 512 bytes buffer in full-speed */
- if ((dev->udev->speed != USB_SPEED_HIGH) &&
- (cmd_len > PCAN_UFD_LOSPD_PKT_SIZE)) {
- packet_len = PCAN_UFD_LOSPD_PKT_SIZE;
- n += cmd_len / packet_len;
- } else {
- packet_len = cmd_len;
- }
+ if (unlikely(dev->udev->speed != USB_SPEED_HIGH))
+ packet_len = min(packet_len, PCAN_UFD_LOSPD_PKT_SIZE);
- for (i = 0; i < n; i++) {
+ do {
err = usb_bulk_msg(dev->udev,
usb_sndbulkpipe(dev->udev,
PCAN_USBPRO_EP_CMDOUT),
@@ -224,7 +220,12 @@ static int pcan_usb_fd_send_cmd(struct peak_usb_device *dev, void *cmd_tail)
}
packet_ptr += packet_len;
- }
+ cmd_len -= packet_len;
+
+ if (cmd_len < PCAN_UFD_LOSPD_PKT_SIZE)
+ packet_len = cmd_len;
+
+ } while (packet_len > 0);
return err;
}
--
2.14.1