@@ -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,
We are seeing IRQ storm on global receive IRQ line under heavy CAN bus load conditions with both CAN channels are enabled. Conditions: The global receive IRQ line is shared between can0 and can1, either of the channels can trigger interrupt while the other channel irq line is disabled(rfie). When global receive IRQ interrupt occurs, we mask the interrupt in irqhandler. Clearing and unmasking of the interrupt is happening in rx_poll(). There is a race condition where rx_poll unmask the interrupt, but the next irq handler does not mask the irq due to NAPIF_STATE_MISSED flag(for eg: can0 rx fifo interrupt enable is disabled and can1 is triggering rx interrupt, the delay in rx_poll() processing results in setting NAPIF_STATE_MISSED flag) leading to 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 <mkl@pengutronix.de> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com> --- v1->v2: * Added check for irq active and enabled before handling the irq on a particular channel. --- drivers/net/can/rcar/rcar_canfd.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)