4.9-stable review patch. If anyone has any objections, please let me know.
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From: Stephane Grosjean s.grosjean@peak-system.com
commit d8a243af1a68395e07ac85384a2740d4134c67f4 upstream.
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@peak-system.com Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/net/can/usb/peak_usb/pcan_usb_fd.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-)
--- 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 p 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 p }
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 p }
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; }