can: rockchip_canfd: add notes about known issues

Even the rk3568v3 has some known issues. Document them together with a
reproducer.
Tested-by: Alibek Omarov <a1ba.omarov@gmail.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patch.msgid.link/20240904-rockchip-canfd-v5-8-8ae22bcb27cc@pengutronix.deSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/rockchip/rockchip_canfd.h

@@ -370,6 +370,26 @@
  */
 #define RKCANFD_QUIRK_CANFD_BROKEN BIT(12)
 
+/* known issues with rk3568v3:
+ *
+ * - Overload situation during high bus load
+ *   To reproduce:
+ *   host:
+ *     # add a 2nd CAN adapter to the CAN bus
+ *     cangen can0 -I 1 -Li -Di -p10 -g 0.3
+ *     cansequence -rve
+ *   DUT:
+ *     cangen can0 -I2 -L1 -Di -p10 -c10 -g 1 -e
+ *     cansequence -rv -i 1
+ *
+ * - TX starvation after repeated Bus-Off
+ *   To reproduce:
+ *   host:
+ *     sleep 3 && cangen can0 -I2 -Li -Di -p10 -g 0.0
+ *   DUT:
+ *     cangen can0 -I2 -Li -Di -p10 -g 0.05
+ */
+
 enum rkcanfd_model {
 	RKCANFD_MODEL_RK3568V2 = 0x35682,
 	RKCANFD_MODEL_RK3568V3 = 0x35683,