From bf66f3736a945dd4e92d86427276c6eeab0a6c1d Mon Sep 17 00:00:00 2001 From: Christian Pellegrin Date: Wed, 3 Feb 2010 07:39:54 +0000 Subject: [PATCH] can: mcp251x: Move to threaded interrupts instead of workqueues. This patch addresses concerns about efficiency of handling incoming packets. Handling of interrupts is done in a threaded interrupt handler which has a smaller latency than workqueues. This change needed a rework of the locking scheme that was much simplified. Some other (more or less longstanding) bugs are fixed: utilization of just half of the RX buffers, useless wait for interrupt on open, more reliable reset sequence. The MERR interrupt is not used anymore: it overloads the CPU in error-passive state without any additional information. One shot mode is disabled because it's not clear if it can be handled efficiently on this CAN controller. Signed-off-by: Christian Pellegrin Acked-by: Wolfgang Grandegger Signed-off-by: David S. Miller --- drivers/net/can/mcp251x.c | 421 ++++++++++++++++++-------------------- 1 file changed, 203 insertions(+), 218 deletions(-) diff --git a/drivers/net/can/mcp251x.c b/drivers/net/can/mcp251x.c index bbe186b5a0ed..f8cc168ec76c 100644 --- a/drivers/net/can/mcp251x.c +++ b/drivers/net/can/mcp251x.c @@ -180,6 +180,14 @@ #define RXBEID0_OFF 4 #define RXBDLC_OFF 5 #define RXBDAT_OFF 6 +#define RXFSIDH(n) ((n) * 4) +#define RXFSIDL(n) ((n) * 4 + 1) +#define RXFEID8(n) ((n) * 4 + 2) +#define RXFEID0(n) ((n) * 4 + 3) +#define RXMSIDH(n) ((n) * 4 + 0x20) +#define RXMSIDL(n) ((n) * 4 + 0x21) +#define RXMEID8(n) ((n) * 4 + 0x22) +#define RXMEID0(n) ((n) * 4 + 0x23) #define GET_BYTE(val, byte) \ (((val) >> ((byte) * 8)) & 0xff) @@ -219,7 +227,8 @@ struct mcp251x_priv { struct net_device *net; struct spi_device *spi; - struct mutex spi_lock; /* SPI buffer lock */ + struct mutex mcp_lock; /* SPI device lock */ + u8 *spi_tx_buf; u8 *spi_rx_buf; dma_addr_t spi_tx_dma; @@ -227,11 +236,11 @@ struct mcp251x_priv { struct sk_buff *tx_skb; int tx_len; + struct workqueue_struct *wq; struct work_struct tx_work; - struct work_struct irq_work; - struct completion awake; - int wake; + struct work_struct restart_work; + int force_quit; int after_suspend; #define AFTER_SUSPEND_UP 1 @@ -245,7 +254,8 @@ static void mcp251x_clean(struct net_device *net) { struct mcp251x_priv *priv = netdev_priv(net); - net->stats.tx_errors++; + if (priv->tx_skb || priv->tx_len) + net->stats.tx_errors++; if (priv->tx_skb) dev_kfree_skb(priv->tx_skb); if (priv->tx_len) @@ -300,16 +310,12 @@ static u8 mcp251x_read_reg(struct spi_device *spi, uint8_t reg) struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); u8 val = 0; - mutex_lock(&priv->spi_lock); - priv->spi_tx_buf[0] = INSTRUCTION_READ; priv->spi_tx_buf[1] = reg; mcp251x_spi_trans(spi, 3); val = priv->spi_rx_buf[2]; - mutex_unlock(&priv->spi_lock); - return val; } @@ -317,15 +323,11 @@ static void mcp251x_write_reg(struct spi_device *spi, u8 reg, uint8_t val) { struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); - mutex_lock(&priv->spi_lock); - priv->spi_tx_buf[0] = INSTRUCTION_WRITE; priv->spi_tx_buf[1] = reg; priv->spi_tx_buf[2] = val; mcp251x_spi_trans(spi, 3); - - mutex_unlock(&priv->spi_lock); } static void mcp251x_write_bits(struct spi_device *spi, u8 reg, @@ -333,16 +335,12 @@ static void mcp251x_write_bits(struct spi_device *spi, u8 reg, { struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); - mutex_lock(&priv->spi_lock); - priv->spi_tx_buf[0] = INSTRUCTION_BIT_MODIFY; priv->spi_tx_buf[1] = reg; priv->spi_tx_buf[2] = mask; priv->spi_tx_buf[3] = val; mcp251x_spi_trans(spi, 4); - - mutex_unlock(&priv->spi_lock); } static void mcp251x_hw_tx_frame(struct spi_device *spi, u8 *buf, @@ -358,10 +356,8 @@ static void mcp251x_hw_tx_frame(struct spi_device *spi, u8 *buf, mcp251x_write_reg(spi, TXBCTRL(tx_buf_idx) + i, buf[i]); } else { - mutex_lock(&priv->spi_lock); memcpy(priv->spi_tx_buf, buf, TXBDAT_OFF + len); mcp251x_spi_trans(spi, TXBDAT_OFF + len); - mutex_unlock(&priv->spi_lock); } } @@ -408,13 +404,9 @@ static void mcp251x_hw_rx_frame(struct spi_device *spi, u8 *buf, for (; i < (RXBDAT_OFF + len); i++) buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i); } else { - mutex_lock(&priv->spi_lock); - priv->spi_tx_buf[RXBCTRL_OFF] = INSTRUCTION_READ_RXB(buf_idx); mcp251x_spi_trans(spi, SPI_TRANSFER_BUF_LEN); memcpy(buf, priv->spi_rx_buf, SPI_TRANSFER_BUF_LEN); - - mutex_unlock(&priv->spi_lock); } } @@ -467,21 +459,6 @@ static void mcp251x_hw_sleep(struct spi_device *spi) mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_SLEEP); } -static void mcp251x_hw_wakeup(struct spi_device *spi) -{ - struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); - - priv->wake = 1; - - /* Can only wake up by generating a wake-up interrupt. */ - mcp251x_write_bits(spi, CANINTE, CANINTE_WAKIE, CANINTE_WAKIE); - mcp251x_write_bits(spi, CANINTF, CANINTF_WAKIF, CANINTF_WAKIF); - - /* Wait until the device is awake */ - if (!wait_for_completion_timeout(&priv->awake, HZ)) - dev_err(&spi->dev, "MCP251x didn't wake-up\n"); -} - static netdev_tx_t mcp251x_hard_start_xmit(struct sk_buff *skb, struct net_device *net) { @@ -490,7 +467,6 @@ static netdev_tx_t mcp251x_hard_start_xmit(struct sk_buff *skb, if (priv->tx_skb || priv->tx_len) { dev_warn(&spi->dev, "hard_xmit called while tx busy\n"); - netif_stop_queue(net); return NETDEV_TX_BUSY; } @@ -511,12 +487,13 @@ static int mcp251x_do_set_mode(struct net_device *net, enum can_mode mode) switch (mode) { case CAN_MODE_START: + mcp251x_clean(net); /* We have to delay work since SPI I/O may sleep */ priv->can.state = CAN_STATE_ERROR_ACTIVE; priv->restart_tx = 1; if (priv->can.restart_ms == 0) priv->after_suspend = AFTER_SUSPEND_RESTART; - queue_work(priv->wq, &priv->irq_work); + queue_work(priv->wq, &priv->restart_work); break; default: return -EOPNOTSUPP; @@ -525,7 +502,7 @@ static int mcp251x_do_set_mode(struct net_device *net, enum can_mode mode) return 0; } -static void mcp251x_set_normal_mode(struct spi_device *spi) +static int mcp251x_set_normal_mode(struct spi_device *spi) { struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); unsigned long timeout; @@ -533,8 +510,7 @@ static void mcp251x_set_normal_mode(struct spi_device *spi) /* Enable interrupts */ mcp251x_write_reg(spi, CANINTE, CANINTE_ERRIE | CANINTE_TX2IE | CANINTE_TX1IE | - CANINTE_TX0IE | CANINTE_RX1IE | CANINTE_RX0IE | - CANINTF_MERRF); + CANINTE_TX0IE | CANINTE_RX1IE | CANINTE_RX0IE); if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) { /* Put device into loopback mode */ @@ -544,9 +520,7 @@ static void mcp251x_set_normal_mode(struct spi_device *spi) mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LISTEN_ONLY); } else { /* Put device into normal mode */ - mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_NORMAL | - (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT ? - CANCTRL_OSM : 0)); + mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_NORMAL); /* Wait for the device to enter normal mode */ timeout = jiffies + HZ; @@ -555,11 +529,12 @@ static void mcp251x_set_normal_mode(struct spi_device *spi) if (time_after(jiffies, timeout)) { dev_err(&spi->dev, "MCP251x didn't" " enter in normal mode\n"); - return; + return -EBUSY; } } } priv->can.state = CAN_STATE_ERROR_ACTIVE; + return 0; } static int mcp251x_do_set_bittiming(struct net_device *net) @@ -590,33 +565,39 @@ static int mcp251x_setup(struct net_device *net, struct mcp251x_priv *priv, { mcp251x_do_set_bittiming(net); - /* Enable RX0->RX1 buffer roll over and disable filters */ - mcp251x_write_bits(spi, RXBCTRL(0), - RXBCTRL_BUKT | RXBCTRL_RXM0 | RXBCTRL_RXM1, - RXBCTRL_BUKT | RXBCTRL_RXM0 | RXBCTRL_RXM1); - mcp251x_write_bits(spi, RXBCTRL(1), - RXBCTRL_RXM0 | RXBCTRL_RXM1, - RXBCTRL_RXM0 | RXBCTRL_RXM1); + mcp251x_write_reg(spi, RXBCTRL(0), + RXBCTRL_BUKT | RXBCTRL_RXM0 | RXBCTRL_RXM1); + mcp251x_write_reg(spi, RXBCTRL(1), + RXBCTRL_RXM0 | RXBCTRL_RXM1); return 0; } -static void mcp251x_hw_reset(struct spi_device *spi) +static int mcp251x_hw_reset(struct spi_device *spi) { struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); int ret; - - mutex_lock(&priv->spi_lock); + unsigned long timeout; priv->spi_tx_buf[0] = INSTRUCTION_RESET; - ret = spi_write(spi, priv->spi_tx_buf, 1); - - mutex_unlock(&priv->spi_lock); - - if (ret) + if (ret) { dev_err(&spi->dev, "reset failed: ret = %d\n", ret); + return -EIO; + } + /* Wait for reset to finish */ + timeout = jiffies + HZ; mdelay(10); + while ((mcp251x_read_reg(spi, CANSTAT) & CANCTRL_REQOP_MASK) + != CANCTRL_REQOP_CONF) { + schedule(); + if (time_after(jiffies, timeout)) { + dev_err(&spi->dev, "MCP251x didn't" + " enter in conf mode after reset\n"); + return -EBUSY; + } + } + return 0; } static int mcp251x_hw_probe(struct spi_device *spi) @@ -640,63 +621,17 @@ static int mcp251x_hw_probe(struct spi_device *spi) return (st1 == 0x80 && st2 == 0x07) ? 1 : 0; } -static irqreturn_t mcp251x_can_isr(int irq, void *dev_id) -{ - struct net_device *net = (struct net_device *)dev_id; - struct mcp251x_priv *priv = netdev_priv(net); - - /* Schedule bottom half */ - if (!work_pending(&priv->irq_work)) - queue_work(priv->wq, &priv->irq_work); - - return IRQ_HANDLED; -} - -static int mcp251x_open(struct net_device *net) +static void mcp251x_open_clean(struct net_device *net) { struct mcp251x_priv *priv = netdev_priv(net); struct spi_device *spi = priv->spi; struct mcp251x_platform_data *pdata = spi->dev.platform_data; - int ret; - - ret = open_candev(net); - if (ret) { - dev_err(&spi->dev, "unable to set initial baudrate!\n"); - return ret; - } + free_irq(spi->irq, priv); + mcp251x_hw_sleep(spi); if (pdata->transceiver_enable) - pdata->transceiver_enable(1); - - priv->force_quit = 0; - priv->tx_skb = NULL; - priv->tx_len = 0; - - ret = request_irq(spi->irq, mcp251x_can_isr, - IRQF_TRIGGER_FALLING, DEVICE_NAME, net); - if (ret) { - dev_err(&spi->dev, "failed to acquire irq %d\n", spi->irq); - if (pdata->transceiver_enable) - pdata->transceiver_enable(0); - close_candev(net); - return ret; - } - - mcp251x_hw_wakeup(spi); - mcp251x_hw_reset(spi); - ret = mcp251x_setup(net, priv, spi); - if (ret) { - free_irq(spi->irq, net); - mcp251x_hw_sleep(spi); - if (pdata->transceiver_enable) - pdata->transceiver_enable(0); - close_candev(net); - return ret; - } - mcp251x_set_normal_mode(spi); - netif_wake_queue(net); - - return 0; + pdata->transceiver_enable(0); + close_candev(net); } static int mcp251x_stop(struct net_device *net) @@ -707,17 +642,19 @@ static int mcp251x_stop(struct net_device *net) close_candev(net); + priv->force_quit = 1; + free_irq(spi->irq, priv); + destroy_workqueue(priv->wq); + priv->wq = NULL; + + mutex_lock(&priv->mcp_lock); + /* Disable and clear pending interrupts */ mcp251x_write_reg(spi, CANINTE, 0x00); mcp251x_write_reg(spi, CANINTF, 0x00); - priv->force_quit = 1; - free_irq(spi->irq, net); - flush_workqueue(priv->wq); - mcp251x_write_reg(spi, TXBCTRL(0), 0); - if (priv->tx_skb || priv->tx_len) - mcp251x_clean(net); + mcp251x_clean(net); mcp251x_hw_sleep(spi); @@ -726,9 +663,27 @@ static int mcp251x_stop(struct net_device *net) priv->can.state = CAN_STATE_STOPPED; + mutex_unlock(&priv->mcp_lock); + return 0; } +static void mcp251x_error_skb(struct net_device *net, int can_id, int data1) +{ + struct sk_buff *skb; + struct can_frame *frame; + + skb = alloc_can_err_skb(net, &frame); + if (skb) { + frame->can_id = can_id; + frame->data[1] = data1; + netif_rx(skb); + } else { + dev_err(&net->dev, + "cannot allocate error skb\n"); + } +} + static void mcp251x_tx_work_handler(struct work_struct *ws) { struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv, @@ -737,33 +692,32 @@ static void mcp251x_tx_work_handler(struct work_struct *ws) struct net_device *net = priv->net; struct can_frame *frame; + mutex_lock(&priv->mcp_lock); if (priv->tx_skb) { - frame = (struct can_frame *)priv->tx_skb->data; - if (priv->can.state == CAN_STATE_BUS_OFF) { mcp251x_clean(net); - netif_wake_queue(net); - return; + } else { + frame = (struct can_frame *)priv->tx_skb->data; + + if (frame->can_dlc > CAN_FRAME_MAX_DATA_LEN) + frame->can_dlc = CAN_FRAME_MAX_DATA_LEN; + mcp251x_hw_tx(spi, frame, 0); + priv->tx_len = 1 + frame->can_dlc; + can_put_echo_skb(priv->tx_skb, net, 0); + priv->tx_skb = NULL; } - if (frame->can_dlc > CAN_FRAME_MAX_DATA_LEN) - frame->can_dlc = CAN_FRAME_MAX_DATA_LEN; - mcp251x_hw_tx(spi, frame, 0); - priv->tx_len = 1 + frame->can_dlc; - can_put_echo_skb(priv->tx_skb, net, 0); - priv->tx_skb = NULL; } + mutex_unlock(&priv->mcp_lock); } -static void mcp251x_irq_work_handler(struct work_struct *ws) +static void mcp251x_restart_work_handler(struct work_struct *ws) { struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv, - irq_work); + restart_work); struct spi_device *spi = priv->spi; struct net_device *net = priv->net; - u8 txbnctrl; - u8 intf; - enum can_state new_state; + mutex_lock(&priv->mcp_lock); if (priv->after_suspend) { mdelay(10); mcp251x_hw_reset(spi); @@ -772,45 +726,54 @@ static void mcp251x_irq_work_handler(struct work_struct *ws) mcp251x_set_normal_mode(spi); } else if (priv->after_suspend & AFTER_SUSPEND_UP) { netif_device_attach(net); - /* Clean since we lost tx buffer */ - if (priv->tx_skb || priv->tx_len) { - mcp251x_clean(net); - netif_wake_queue(net); - } + mcp251x_clean(net); mcp251x_set_normal_mode(spi); + netif_wake_queue(net); } else { mcp251x_hw_sleep(spi); } priv->after_suspend = 0; + priv->force_quit = 0; } - if (priv->can.restart_ms == 0 && priv->can.state == CAN_STATE_BUS_OFF) - return; + if (priv->restart_tx) { + priv->restart_tx = 0; + mcp251x_write_reg(spi, TXBCTRL(0), 0); + mcp251x_clean(net); + netif_wake_queue(net); + mcp251x_error_skb(net, CAN_ERR_RESTARTED, 0); + } + mutex_unlock(&priv->mcp_lock); +} - while (!priv->force_quit && !freezing(current)) { - u8 eflag = mcp251x_read_reg(spi, EFLG); - int can_id = 0, data1 = 0; +static irqreturn_t mcp251x_can_ist(int irq, void *dev_id) +{ + struct mcp251x_priv *priv = dev_id; + struct spi_device *spi = priv->spi; + struct net_device *net = priv->net; - mcp251x_write_reg(spi, EFLG, 0x00); + mutex_lock(&priv->mcp_lock); + while (!priv->force_quit) { + enum can_state new_state; + u8 intf = mcp251x_read_reg(spi, CANINTF); + u8 eflag; + int can_id = 0, data1 = 0; - if (priv->restart_tx) { - priv->restart_tx = 0; - mcp251x_write_reg(spi, TXBCTRL(0), 0); - if (priv->tx_skb || priv->tx_len) - mcp251x_clean(net); - netif_wake_queue(net); - can_id |= CAN_ERR_RESTARTED; + if (intf & CANINTF_RX0IF) { + mcp251x_hw_rx(spi, 0); + /* Free one buffer ASAP */ + mcp251x_write_bits(spi, CANINTF, intf & CANINTF_RX0IF, + 0x00); } - if (priv->wake) { - /* Wait whilst the device wakes up */ - mdelay(10); - priv->wake = 0; - } + if (intf & CANINTF_RX1IF) + mcp251x_hw_rx(spi, 1); - intf = mcp251x_read_reg(spi, CANINTF); mcp251x_write_bits(spi, CANINTF, intf, 0x00); + eflag = mcp251x_read_reg(spi, EFLG); + mcp251x_write_reg(spi, EFLG, 0x00); + /* Update can state */ if (eflag & EFLG_TXBO) { new_state = CAN_STATE_BUS_OFF; @@ -851,59 +814,31 @@ static void mcp251x_irq_work_handler(struct work_struct *ws) } priv->can.state = new_state; - if ((intf & CANINTF_ERRIF) || (can_id & CAN_ERR_RESTARTED)) { - struct sk_buff *skb; - struct can_frame *frame; - - /* Create error frame */ - skb = alloc_can_err_skb(net, &frame); - if (skb) { - /* Set error frame flags based on bus state */ - frame->can_id = can_id; - frame->data[1] = data1; - - /* Update net stats for overflows */ - if (eflag & (EFLG_RX0OVR | EFLG_RX1OVR)) { - if (eflag & EFLG_RX0OVR) - net->stats.rx_over_errors++; - if (eflag & EFLG_RX1OVR) - net->stats.rx_over_errors++; - frame->can_id |= CAN_ERR_CRTL; - frame->data[1] |= - CAN_ERR_CRTL_RX_OVERFLOW; - } - - netif_rx(skb); - } else { - dev_info(&spi->dev, - "cannot allocate error skb\n"); + if (intf & CANINTF_ERRIF) { + /* Handle overflow counters */ + if (eflag & (EFLG_RX0OVR | EFLG_RX1OVR)) { + if (eflag & EFLG_RX0OVR) + net->stats.rx_over_errors++; + if (eflag & EFLG_RX1OVR) + net->stats.rx_over_errors++; + can_id |= CAN_ERR_CRTL; + data1 |= CAN_ERR_CRTL_RX_OVERFLOW; } + mcp251x_error_skb(net, can_id, data1); } if (priv->can.state == CAN_STATE_BUS_OFF) { if (priv->can.restart_ms == 0) { + priv->force_quit = 1; can_bus_off(net); mcp251x_hw_sleep(spi); - return; + break; } } if (intf == 0) break; - if (intf & CANINTF_WAKIF) - complete(&priv->awake); - - if (intf & CANINTF_MERRF) { - /* If there are pending Tx buffers, restart queue */ - txbnctrl = mcp251x_read_reg(spi, TXBCTRL(0)); - if (!(txbnctrl & TXBCTRL_TXREQ)) { - if (priv->tx_skb || priv->tx_len) - mcp251x_clean(net); - netif_wake_queue(net); - } - } - if (intf & (CANINTF_TX2IF | CANINTF_TX1IF | CANINTF_TX0IF)) { net->stats.tx_packets++; net->stats.tx_bytes += priv->tx_len - 1; @@ -914,12 +849,66 @@ static void mcp251x_irq_work_handler(struct work_struct *ws) netif_wake_queue(net); } - if (intf & CANINTF_RX0IF) - mcp251x_hw_rx(spi, 0); + } + mutex_unlock(&priv->mcp_lock); + return IRQ_HANDLED; +} - if (intf & CANINTF_RX1IF) - mcp251x_hw_rx(spi, 1); +static int mcp251x_open(struct net_device *net) +{ + struct mcp251x_priv *priv = netdev_priv(net); + struct spi_device *spi = priv->spi; + struct mcp251x_platform_data *pdata = spi->dev.platform_data; + int ret; + + ret = open_candev(net); + if (ret) { + dev_err(&spi->dev, "unable to set initial baudrate!\n"); + return ret; + } + + mutex_lock(&priv->mcp_lock); + if (pdata->transceiver_enable) + pdata->transceiver_enable(1); + + priv->force_quit = 0; + priv->tx_skb = NULL; + priv->tx_len = 0; + + ret = request_threaded_irq(spi->irq, NULL, mcp251x_can_ist, + IRQF_TRIGGER_FALLING, DEVICE_NAME, priv); + if (ret) { + dev_err(&spi->dev, "failed to acquire irq %d\n", spi->irq); + if (pdata->transceiver_enable) + pdata->transceiver_enable(0); + close_candev(net); + goto open_unlock; + } + + priv->wq = create_freezeable_workqueue("mcp251x_wq"); + INIT_WORK(&priv->tx_work, mcp251x_tx_work_handler); + INIT_WORK(&priv->restart_work, mcp251x_restart_work_handler); + + ret = mcp251x_hw_reset(spi); + if (ret) { + mcp251x_open_clean(net); + goto open_unlock; + } + ret = mcp251x_setup(net, priv, spi); + if (ret) { + mcp251x_open_clean(net); + goto open_unlock; } + ret = mcp251x_set_normal_mode(spi); + if (ret) { + mcp251x_open_clean(net); + goto open_unlock; + } + netif_wake_queue(net); + +open_unlock: + mutex_unlock(&priv->mcp_lock); + return ret; } static const struct net_device_ops mcp251x_netdev_ops = { @@ -955,13 +944,11 @@ static int __devinit mcp251x_can_probe(struct spi_device *spi) priv->can.clock.freq = pdata->oscillator_frequency / 2; priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_LOOPBACK | CAN_CTRLMODE_LISTENONLY; - if (pdata->model == CAN_MCP251X_MCP2515) - priv->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT; priv->net = net; dev_set_drvdata(&spi->dev, priv); priv->spi = spi; - mutex_init(&priv->spi_lock); + mutex_init(&priv->mcp_lock); /* If requested, allocate DMA buffers */ if (mcp251x_enable_dma) { @@ -1010,18 +997,12 @@ static int __devinit mcp251x_can_probe(struct spi_device *spi) SET_NETDEV_DEV(net, &spi->dev); - priv->wq = create_freezeable_workqueue("mcp251x_wq"); - - INIT_WORK(&priv->tx_work, mcp251x_tx_work_handler); - INIT_WORK(&priv->irq_work, mcp251x_irq_work_handler); - - init_completion(&priv->awake); - /* Configure the SPI bus */ spi->mode = SPI_MODE_0; spi->bits_per_word = 8; spi_setup(spi); + /* Here is OK to not lock the MCP, no one knows about it yet */ if (!mcp251x_hw_probe(spi)) { dev_info(&spi->dev, "Probe failed\n"); goto error_probe; @@ -1064,10 +1045,6 @@ static int __devexit mcp251x_can_remove(struct spi_device *spi) unregister_candev(net); free_candev(net); - priv->force_quit = 1; - flush_workqueue(priv->wq); - destroy_workqueue(priv->wq); - if (mcp251x_enable_dma) { dma_free_coherent(&spi->dev, PAGE_SIZE, priv->spi_tx_buf, priv->spi_tx_dma); @@ -1089,6 +1066,12 @@ static int mcp251x_can_suspend(struct spi_device *spi, pm_message_t state) struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev); struct net_device *net = priv->net; + priv->force_quit = 1; + disable_irq(spi->irq); + /* + * Note: at this point neither IST nor workqueues are running. + * open/stop cannot be called anyway so locking is not needed + */ if (netif_running(net)) { netif_device_detach(net); @@ -1115,16 +1098,18 @@ static int mcp251x_can_resume(struct spi_device *spi) if (priv->after_suspend & AFTER_SUSPEND_POWER) { pdata->power_enable(1); - queue_work(priv->wq, &priv->irq_work); + queue_work(priv->wq, &priv->restart_work); } else { if (priv->after_suspend & AFTER_SUSPEND_UP) { if (pdata->transceiver_enable) pdata->transceiver_enable(1); - queue_work(priv->wq, &priv->irq_work); + queue_work(priv->wq, &priv->restart_work); } else { priv->after_suspend = 0; } } + priv->force_quit = 0; + enable_irq(spi->irq); return 0; } #else -- GitLab