3 files changed, 136 insertions, 68 deletions

diff --git a/Documentation/networking/can.txt b/Documentation/networking/can.txt
index f3089d423515..0cbe6ec22d6f 100644
--- a/Documentation/networking/can.txt
+++ b/Documentation/networking/can.txt
@@ -554,12 +554,6 @@ solution for a couple of reasons:
   not specified in the struct can_frame and therefore it is only valid in
   CANFD_MTU sized CAN FD frames.
 
-  As long as the payload length is <=8 the received CAN frames from CAN FD
-  capable CAN devices can be received and read by legacy sockets too. When
-  user-generated CAN FD frames have a payload length <=8 these can be send
-  by legacy CAN network interfaces too. Sending CAN FD frames with payload
-  length > 8 to a legacy CAN network interface returns an -EMSGSIZE error.
-
   Implementation hint for new CAN applications:
 
   To build a CAN FD aware application use struct canfd_frame as basic CAN
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 320bef2dba42..61376abdab39 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -144,6 +144,8 @@
 
 #define FLEXCAN_MB_CODE_MASK            (0xf0ffffff)
 
+#define FLEXCAN_TIMEOUT_US             (50)
+
 /*
  * FLEXCAN hardware feature flags
  *
@@ -262,6 +264,22 @@ static inline void flexcan_write(u32 val, void __iomem *addr)
 }
 #endif
 
+static inline int flexcan_transceiver_enable(const struct flexcan_priv *priv)
+{
+        if (!priv->reg_xceiver)
+                return 0;
+
+        return regulator_enable(priv->reg_xceiver);
+}
+
+static inline int flexcan_transceiver_disable(const struct flexcan_priv *priv)
+{
+        if (!priv->reg_xceiver)
+                return 0;
+
+        return regulator_disable(priv->reg_xceiver);
+}
+
 static inline int flexcan_has_and_handle_berr(const struct flexcan_priv *priv,
                                               u32 reg_esr)
 {
@@ -269,26 +287,95 @@ static inline int flexcan_has_and_handle_berr(const struct flexcan_priv *priv,
                 (reg_esr & FLEXCAN_ESR_ERR_BUS);
 }
 
-static inline void flexcan_chip_enable(struct flexcan_priv *priv)
+static int flexcan_chip_enable(struct flexcan_priv *priv)
 {
         struct flexcan_regs __iomem *regs = priv->base;
+        unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
         u32 reg;
 
         reg = flexcan_read(&regs->mcr);
         reg &= ~FLEXCAN_MCR_MDIS;
         flexcan_write(reg, &regs->mcr);
 
-        udelay(10);
+        while (timeout-- && (flexcan_read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK))
+                usleep_range(10, 20);
+
+        if (flexcan_read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK)
+                return -ETIMEDOUT;
+
+        return 0;
 }
 
-static inline void flexcan_chip_disable(struct flexcan_priv *priv)
+static int flexcan_chip_disable(struct flexcan_priv *priv)
 {
         struct flexcan_regs __iomem *regs = priv->base;
+        unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
         u32 reg;
 
         reg = flexcan_read(&regs->mcr);
         reg |= FLEXCAN_MCR_MDIS;
         flexcan_write(reg, &regs->mcr);
+
+        while (timeout-- && !(flexcan_read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK))
+                usleep_range(10, 20);
+
+        if (!(flexcan_read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK))
+                return -ETIMEDOUT;
+
+        return 0;
+}
+
+static int flexcan_chip_freeze(struct flexcan_priv *priv)
+{
+        struct flexcan_regs __iomem *regs = priv->base;
+        unsigned int timeout = 1000 * 1000 * 10 / priv->can.bittiming.bitrate;
+        u32 reg;
+
+        reg = flexcan_read(&regs->mcr);
+        reg |= FLEXCAN_MCR_HALT;
+        flexcan_write(reg, &regs->mcr);
+
+        while (timeout-- && !(flexcan_read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
+                usleep_range(100, 200);
+
+        if (!(flexcan_read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
+                return -ETIMEDOUT;
+
+        return 0;
+}
+
+static int flexcan_chip_unfreeze(struct flexcan_priv *priv)
+{
+        struct flexcan_regs __iomem *regs = priv->base;
+        unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
+        u32 reg;
+
+        reg = flexcan_read(&regs->mcr);
+        reg &= ~FLEXCAN_MCR_HALT;
+        flexcan_write(reg, &regs->mcr);
+
+        while (timeout-- && (flexcan_read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
+                usleep_range(10, 20);
+
+        if (flexcan_read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK)
+                return -ETIMEDOUT;
+
+        return 0;
+}
+
+static int flexcan_chip_softreset(struct flexcan_priv *priv)
+{
+        struct flexcan_regs __iomem *regs = priv->base;
+        unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
+
+        flexcan_write(FLEXCAN_MCR_SOFTRST, &regs->mcr);
+        while (timeout-- && (flexcan_read(&regs->mcr) & FLEXCAN_MCR_SOFTRST))
+                usleep_range(10, 20);
+
+        if (flexcan_read(&regs->mcr) & FLEXCAN_MCR_SOFTRST)
+                return -ETIMEDOUT;
+
+        return 0;
 }
 
 static int flexcan_get_berr_counter(const struct net_device *dev,
@@ -709,19 +796,14 @@ static int flexcan_chip_start(struct net_device *dev)
         u32 reg_mcr, reg_ctrl;
 
         /* enable module */
-        flexcan_chip_enable(priv);
+        err = flexcan_chip_enable(priv);
+        if (err)
+                return err;
 
         /* soft reset */
-        flexcan_write(FLEXCAN_MCR_SOFTRST, &regs->mcr);
-        udelay(10);
-
-        reg_mcr = flexcan_read(&regs->mcr);
-        if (reg_mcr & FLEXCAN_MCR_SOFTRST) {
-                netdev_err(dev, "Failed to softreset can module (mcr=0x%08x)\n",
-                           reg_mcr);
-                err = -ENODEV;
-                goto out;
-        }
+        err = flexcan_chip_softreset(priv);
+        if (err)
+                goto out_chip_disable;
 
         flexcan_set_bittiming(dev);
 
@@ -788,16 +870,14 @@ static int flexcan_chip_start(struct net_device *dev)
         if (priv->devtype_data->features & FLEXCAN_HAS_V10_FEATURES)
                 flexcan_write(0x0, &regs->rxfgmask);
 
-        if (priv->reg_xceiver)  {
-                err = regulator_enable(priv->reg_xceiver);
-                if (err)
-                        goto out;
-        }
+        err = flexcan_transceiver_enable(priv);
+        if (err)
+                goto out_chip_disable;
 
         /* synchronize with the can bus */
-        reg_mcr = flexcan_read(&regs->mcr);
-        reg_mcr &= ~FLEXCAN_MCR_HALT;
-        flexcan_write(reg_mcr, &regs->mcr);
+        err = flexcan_chip_unfreeze(priv);
+        if (err)
+                goto out_transceiver_disable;
 
         priv->can.state = CAN_STATE_ERROR_ACTIVE;
 
@@ -810,7 +890,9 @@ static int flexcan_chip_start(struct net_device *dev)
 
         return 0;
 
- out:
+ out_transceiver_disable:
+        flexcan_transceiver_disable(priv);
+ out_chip_disable:
         flexcan_chip_disable(priv);
         return err;
 }
@@ -825,18 +907,17 @@ static void flexcan_chip_stop(struct net_device *dev)
 {
         struct flexcan_priv *priv = netdev_priv(dev);
         struct flexcan_regs __iomem *regs = priv->base;
-        u32 reg;
+
+        /* freeze + disable module */
+        flexcan_chip_freeze(priv);
+        flexcan_chip_disable(priv);
 
         /* Disable all interrupts */
         flexcan_write(0, &regs->imask1);
+        flexcan_write(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_ALL,
+                      &regs->ctrl);
 
-        /* Disable + halt module */
-        reg = flexcan_read(&regs->mcr);
-        reg |= FLEXCAN_MCR_MDIS | FLEXCAN_MCR_HALT;
-        flexcan_write(reg, &regs->mcr);
-
-        if (priv->reg_xceiver)
-                regulator_disable(priv->reg_xceiver);
+        flexcan_transceiver_disable(priv);
         priv->can.state = CAN_STATE_STOPPED;
 
         return;
@@ -866,7 +947,7 @@ static int flexcan_open(struct net_device *dev)
         /* start chip and queuing */
         err = flexcan_chip_start(dev);
         if (err)
-                goto out_close;
+                goto out_free_irq;
 
         can_led_event(dev, CAN_LED_EVENT_OPEN);
 
@@ -875,6 +956,8 @@ static int flexcan_open(struct net_device *dev)
 
         return 0;
 
+ out_free_irq:
+        free_irq(dev->irq, dev);
  out_close:
         close_candev(dev);
  out_disable_per:
@@ -945,12 +1028,16 @@ static int register_flexcandev(struct net_device *dev)
                 goto out_disable_ipg;
 
         /* select "bus clock", chip must be disabled */
-        flexcan_chip_disable(priv);
+        err = flexcan_chip_disable(priv);
+        if (err)
+                goto out_disable_per;
         reg = flexcan_read(&regs->ctrl);
         reg |= FLEXCAN_CTRL_CLK_SRC;
         flexcan_write(reg, &regs->ctrl);
 
-        flexcan_chip_enable(priv);
+        err = flexcan_chip_enable(priv);
+        if (err)
+                goto out_chip_disable;
 
         /* set freeze, halt and activate FIFO, restrict register access */
         reg = flexcan_read(&regs->mcr);
@@ -967,14 +1054,15 @@ static int register_flexcandev(struct net_device *dev)
         if (!(reg & FLEXCAN_MCR_FEN)) {
                 netdev_err(dev, "Could not enable RX FIFO, unsupported core\n");
                 err = -ENODEV;
-                goto out_disable_per;
+                goto out_chip_disable;
         }
 
         err = register_candev(dev);
 
- out_disable_per:
         /* disable core and turn off clocks */
+ out_chip_disable:
         flexcan_chip_disable(priv);
+ out_disable_per:
         clk_disable_unprepare(priv->clk_per);
  out_disable_ipg:
         clk_disable_unprepare(priv->clk_ipg);
@@ -1104,9 +1192,10 @@ static int flexcan_probe(struct platform_device *pdev)
 static int flexcan_remove(struct platform_device *pdev)
 {
         struct net_device *dev = platform_get_drvdata(pdev);
+        struct flexcan_priv *priv = netdev_priv(dev);
 
         unregister_flexcandev(dev);
-
+        netif_napi_del(&priv->napi);
         free_candev(dev);
 
         return 0;
@@ -1117,8 +1206,11 @@ static int flexcan_suspend(struct device *device)
 {
         struct net_device *dev = dev_get_drvdata(device);
         struct flexcan_priv *priv = netdev_priv(dev);
+        int err;
 
-        flexcan_chip_disable(priv);
+        err = flexcan_chip_disable(priv);
+        if (err)
+                return err;
 
         if (netif_running(dev)) {
                 netif_stop_queue(dev);
@@ -1139,9 +1231,7 @@ static int flexcan_resume(struct device *device)
                 netif_device_attach(dev);
                 netif_start_queue(dev);
         }
-        flexcan_chip_enable(priv);
-
-        return 0;
+        return flexcan_chip_enable(priv);
 }
 #endif /* CONFIG_PM_SLEEP */
 
diff --git a/net/can/raw.c b/net/can/raw.c
index 8be757cca2ec..081e81fd017f 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -121,13 +121,9 @@ static void raw_rcv(struct sk_buff *oskb, void *data)
         if (!ro->recv_own_msgs && oskb->sk == sk)
                 return;
 
-        /* do not pass frames with DLC > 8 to a legacy socket */
-        if (!ro->fd_frames) {
-                struct canfd_frame *cfd = (struct canfd_frame *)oskb->data;
-
-                if (unlikely(cfd->len > CAN_MAX_DLEN))
-                        return;
-        }
+        /* do not pass non-CAN2.0 frames to a legacy socket */
+        if (!ro->fd_frames && oskb->len != CAN_MTU)
+                return;
 
         /* clone the given skb to be able to enqueue it into the rcv queue */
         skb = skb_clone(oskb, GFP_ATOMIC);
@@ -738,9 +734,7 @@ static int raw_recvmsg(struct kiocb *iocb, struct socket *sock,
                        struct msghdr *msg, size_t size, int flags)
 {
         struct sock *sk = sock->sk;
-        struct raw_sock *ro = raw_sk(sk);
         struct sk_buff *skb;
-        int rxmtu;
         int err = 0;
         int noblock;
 
@@ -751,20 +745,10 @@ static int raw_recvmsg(struct kiocb *iocb, struct socket *sock,
         if (!skb)
                 return err;
 
-        /*
-         * when serving a legacy socket the DLC <= 8 is already checked inside
-         * raw_rcv(). Now check if we need to pass a canfd_frame to a legacy
-         * socket and cut the possible CANFD_MTU/CAN_MTU length to CAN_MTU
-         */
-        if (!ro->fd_frames)
-                rxmtu = CAN_MTU;
-        else
-                rxmtu = skb->len;
-
-        if (size < rxmtu)
+        if (size < skb->len)
                 msg->msg_flags |= MSG_TRUNC;
         else
-                size = rxmtu;
+                size = skb->len;
 
         err = memcpy_toiovec(msg->msg_iov, skb->data, size);
         if (err < 0) {