From 702de2c21eed04c67cefaaedc248ef16e5f6b293 Mon Sep 17 00:00:00 2001 From: Biju Das Date: Tue, 25 Oct 2022 16:56:55 +0100 Subject: [PATCH 1/2] can: rcar_canfd: rcar_canfd_handle_global_receive(): fix IRQ storm on global FIFO receive We are seeing an IRQ storm on the global receive IRQ line under heavy CAN bus load conditions with both CAN channels enabled. Conditions: The global receive IRQ line is shared between can0 and can1, either of the channels can trigger interrupt while the other channel's IRQ line is disabled (RFIE). When global a receive IRQ interrupt occurs, we mask the interrupt in the IRQ handler. Clearing and unmasking of the interrupt is happening in rx_poll(). There is a race condition where rx_poll() unmasks the interrupt, but the next IRQ handler does not mask the IRQ due to NAPIF_STATE_MISSED flag (e.g.: can0 RX FIFO interrupt is disabled and can1 is triggering RX interrupt, the delay in rx_poll() processing results in setting NAPIF_STATE_MISSED flag) leading to an IRQ storm. This patch fixes the issue by checking IRQ active and enabled before handling the IRQ on a particular channel. Fixes: dd3bd23eb438 ("can: rcar_canfd: Add Renesas R-Car CAN FD driver") Suggested-by: Marc Kleine-Budde Signed-off-by: Biju Das Link: https://lore.kernel.org/all/20221025155657.1426948-2-biju.das.jz@bp.renesas.com Cc: stable@vger.kernel.org [mkl: adjust commit message] Signed-off-by: Marc Kleine-Budde --- drivers/net/can/rcar/rcar_canfd.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c index 567620d215f8..ea828c1bd3a1 100644 --- a/drivers/net/can/rcar/rcar_canfd.c +++ b/drivers/net/can/rcar/rcar_canfd.c @@ -1157,11 +1157,13 @@ static void rcar_canfd_handle_global_receive(struct rcar_canfd_global *gpriv, u3 { struct rcar_canfd_channel *priv = gpriv->ch[ch]; u32 ridx = ch + RCANFD_RFFIFO_IDX; - u32 sts; + u32 sts, cc; /* Handle Rx interrupts */ sts = rcar_canfd_read(priv->base, RCANFD_RFSTS(gpriv, ridx)); - if (likely(sts & RCANFD_RFSTS_RFIF)) { + cc = rcar_canfd_read(priv->base, RCANFD_RFCC(gpriv, ridx)); + if (likely(sts & RCANFD_RFSTS_RFIF && + cc & RCANFD_RFCC_RFIE)) { if (napi_schedule_prep(&priv->napi)) { /* Disable Rx FIFO interrupts */ rcar_canfd_clear_bit(priv->base, From d887087c896881715c1a82f1d4f71fbfe5344ffd Mon Sep 17 00:00:00 2001 From: Biju Das Date: Tue, 25 Oct 2022 16:56:56 +0100 Subject: [PATCH 2/2] can: rcar_canfd: fix channel specific IRQ handling for RZ/G2L RZ/G2L has separate channel specific IRQs for transmit and error interrupts. But the IRQ handler processes both channels, even if there no interrupt occurred on one of the channels. This patch fixes the issue by passing a channel specific context parameter instead of global one for the IRQ register and the IRQ handler, it just handles the channel which is triggered the interrupt. Fixes: 76e9353a80e9 ("can: rcar_canfd: Add support for RZ/G2L family") Signed-off-by: Biju Das Link: https://lore.kernel.org/all/20221025155657.1426948-3-biju.das.jz@bp.renesas.com Cc: stable@vger.kernel.org [mkl: adjust commit message] Signed-off-by: Marc Kleine-Budde --- drivers/net/can/rcar/rcar_canfd.c | 18 +++++++----------- 1 file changed, 7 insertions(+), 11 deletions(-) diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c index ea828c1bd3a1..198da643ee6d 100644 --- a/drivers/net/can/rcar/rcar_canfd.c +++ b/drivers/net/can/rcar/rcar_canfd.c @@ -1246,11 +1246,9 @@ static void rcar_canfd_handle_channel_tx(struct rcar_canfd_global *gpriv, u32 ch static irqreturn_t rcar_canfd_channel_tx_interrupt(int irq, void *dev_id) { - struct rcar_canfd_global *gpriv = dev_id; - u32 ch; + struct rcar_canfd_channel *priv = dev_id; - for_each_set_bit(ch, &gpriv->channels_mask, gpriv->max_channels) - rcar_canfd_handle_channel_tx(gpriv, ch); + rcar_canfd_handle_channel_tx(priv->gpriv, priv->channel); return IRQ_HANDLED; } @@ -1278,11 +1276,9 @@ static void rcar_canfd_handle_channel_err(struct rcar_canfd_global *gpriv, u32 c static irqreturn_t rcar_canfd_channel_err_interrupt(int irq, void *dev_id) { - struct rcar_canfd_global *gpriv = dev_id; - u32 ch; + struct rcar_canfd_channel *priv = dev_id; - for_each_set_bit(ch, &gpriv->channels_mask, gpriv->max_channels) - rcar_canfd_handle_channel_err(gpriv, ch); + rcar_canfd_handle_channel_err(priv->gpriv, priv->channel); return IRQ_HANDLED; } @@ -1723,6 +1719,7 @@ static int rcar_canfd_channel_probe(struct rcar_canfd_global *gpriv, u32 ch, priv->ndev = ndev; priv->base = gpriv->base; priv->channel = ch; + priv->gpriv = gpriv; priv->can.clock.freq = fcan_freq; dev_info(&pdev->dev, "can_clk rate is %u\n", priv->can.clock.freq); @@ -1751,7 +1748,7 @@ static int rcar_canfd_channel_probe(struct rcar_canfd_global *gpriv, u32 ch, } err = devm_request_irq(&pdev->dev, err_irq, rcar_canfd_channel_err_interrupt, 0, - irq_name, gpriv); + irq_name, priv); if (err) { dev_err(&pdev->dev, "devm_request_irq CH Err(%d) failed, error %d\n", err_irq, err); @@ -1765,7 +1762,7 @@ static int rcar_canfd_channel_probe(struct rcar_canfd_global *gpriv, u32 ch, } err = devm_request_irq(&pdev->dev, tx_irq, rcar_canfd_channel_tx_interrupt, 0, - irq_name, gpriv); + irq_name, priv); if (err) { dev_err(&pdev->dev, "devm_request_irq Tx (%d) failed, error %d\n", tx_irq, err); @@ -1791,7 +1788,6 @@ static int rcar_canfd_channel_probe(struct rcar_canfd_global *gpriv, u32 ch, priv->can.do_set_mode = rcar_canfd_do_set_mode; priv->can.do_get_berr_counter = rcar_canfd_get_berr_counter; - priv->gpriv = gpriv; SET_NETDEV_DEV(ndev, &pdev->dev); netif_napi_add_weight(ndev, &priv->napi, rcar_canfd_rx_poll,