can: pcan_usb: don't provide CAN FD bittimings by non-FD adapters

The CAN FD data bittiming constants are provided via netlink only when there
are valid CAN FD constants available in priv->data_bittiming_const.

Due to the indirection of pointer assignments in the peak_usb driver the
priv->data_bittiming_const never becomes NULL - not even for non-FD adapters.

The data_bittiming_const points to zero'ed data which leads to this result
when running 'ip -details link show can0':

35: can0: <NOARP,ECHO> mtu 16 qdisc noop state DOWN mode DEFAULT group default qlen 10
    link/can  promiscuity 0
    can state STOPPED restart-ms 0
	  pcan_usb: tseg1 1..16 tseg2 1..8 sjw 1..4 brp 1..64 brp-inc 1
	  : dtseg1 0..0 dtseg2 0..0 dsjw 1..0 dbrp 0..0 dbrp-inc 0  <== BROKEN!
	  clock 8000000

This patch changes the struct peak_usb_adapter::bittiming_const and struct
peak_usb_adapter::data_bittiming_const to pointers to fix the assignemnt
problems.

Cc: linux-stable <stable@vger.kernel.org> # >= 4.0
Reported-by: Oliver Hartkopp <socketcan@hartkopp.net>
Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

1 files changed, 52 insertions, 44 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 09d14e70abd7..ce44a033f63b 100644
--- a/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
+++ b/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
@@ -990,6 +990,30 @@ static void pcan_usb_fd_free(struct peak_usb_device *dev)
 }
 
 /* describes the PCAN-USB FD adapter */
+static const struct can_bittiming_const pcan_usb_fd_const = {
+	.name = "pcan_usb_fd",
+	.tseg1_min = 1,
+	.tseg1_max = 64,
+	.tseg2_min = 1,
+	.tseg2_max = 16,
+	.sjw_max = 16,
+	.brp_min = 1,
+	.brp_max = 1024,
+	.brp_inc = 1,
+};
+
+static const struct can_bittiming_const pcan_usb_fd_data_const = {
+	.name = "pcan_usb_fd",
+	.tseg1_min = 1,
+	.tseg1_max = 16,
+	.tseg2_min = 1,
+	.tseg2_max = 8,
+	.sjw_max = 4,
+	.brp_min = 1,
+	.brp_max = 1024,
+	.brp_inc = 1,
+};
+
 const struct peak_usb_adapter pcan_usb_fd = {
 	.name = "PCAN-USB FD",
 	.device_id = PCAN_USBFD_PRODUCT_ID,
@@ -999,28 +1023,8 @@ const struct peak_usb_adapter pcan_usb_fd = {
 	.clock = {
 		.freq = PCAN_UFD_CRYSTAL_HZ,
 	},
-	.bittiming_const = {
-		.name = "pcan_usb_fd",
-		.tseg1_min = 1,
-		.tseg1_max = 64,
-		.tseg2_min = 1,
-		.tseg2_max = 16,
-		.sjw_max = 16,
-		.brp_min = 1,
-		.brp_max = 1024,
-		.brp_inc = 1,
-	},
-	.data_bittiming_const = {
-		.name = "pcan_usb_fd",
-		.tseg1_min = 1,
-		.tseg1_max = 16,
-		.tseg2_min = 1,
-		.tseg2_max = 8,
-		.sjw_max = 4,
-		.brp_min = 1,
-		.brp_max = 1024,
-		.brp_inc = 1,
-	},
+	.bittiming_const = &pcan_usb_fd_const,
+	.data_bittiming_const = &pcan_usb_fd_data_const,
 
 	/* size of device private data */
 	.sizeof_dev_private = sizeof(struct pcan_usb_fd_device),
@@ -1058,6 +1062,30 @@ const struct peak_usb_adapter pcan_usb_fd = {
 };
 
 /* describes the PCAN-USB Pro FD adapter */
+static const struct can_bittiming_const pcan_usb_pro_fd_const = {
+	.name = "pcan_usb_pro_fd",
+	.tseg1_min = 1,
+	.tseg1_max = 64,
+	.tseg2_min = 1,
+	.tseg2_max = 16,
+	.sjw_max = 16,
+	.brp_min = 1,
+	.brp_max = 1024,
+	.brp_inc = 1,
+};
+
+static const struct can_bittiming_const pcan_usb_pro_fd_data_const = {
+	.name = "pcan_usb_pro_fd",
+	.tseg1_min = 1,
+	.tseg1_max = 16,
+	.tseg2_min = 1,
+	.tseg2_max = 8,
+	.sjw_max = 4,
+	.brp_min = 1,
+	.brp_max = 1024,
+	.brp_inc = 1,
+};
+
 const struct peak_usb_adapter pcan_usb_pro_fd = {
 	.name = "PCAN-USB Pro FD",
 	.device_id = PCAN_USBPROFD_PRODUCT_ID,
@@ -1067,28 +1095,8 @@ const struct peak_usb_adapter pcan_usb_pro_fd = {
 	.clock = {
 		.freq = PCAN_UFD_CRYSTAL_HZ,
 	},
-	.bittiming_const = {
-		.name = "pcan_usb_pro_fd",
-		.tseg1_min = 1,
-		.tseg1_max = 64,
-		.tseg2_min = 1,
-		.tseg2_max = 16,
-		.sjw_max = 16,
-		.brp_min = 1,
-		.brp_max = 1024,
-		.brp_inc = 1,
-	},
-	.data_bittiming_const = {
-		.name = "pcan_usb_pro_fd",
-		.tseg1_min = 1,
-		.tseg1_max = 16,
-		.tseg2_min = 1,
-		.tseg2_max = 8,
-		.sjw_max = 4,
-		.brp_min = 1,
-		.brp_max = 1024,
-		.brp_inc = 1,
-	},
+	.bittiming_const = &pcan_usb_pro_fd_const,
+	.data_bittiming_const = &pcan_usb_pro_fd_data_const,
 
 	/* size of device private data */
 	.sizeof_dev_private = sizeof(struct pcan_usb_fd_device),