4.19-stable patches

added patches:
	can-rcar_canfd-rcar_canfd_handle_global_receive-fix-irq-storm-on-global-fifo-receive.patch

diff --git a/queue-4.19/can-rcar_canfd-rcar_canfd_handle_global_receive-fix-irq-storm-on-global-fifo-receive.patch b/queue-4.19/can-rcar_canfd-rcar_canfd_handle_global_receive-fix-irq-storm-on-global-fifo-receive.patch
new file mode 100644 (file)
index 0000000..2f36676
--- /dev/null
+++ b/queue-4.19/can-rcar_canfd-rcar_canfd_handle_global_receive-fix-irq-storm-on-global-fifo-receive.patch
@@ -0,0 +1,65 @@
+From 702de2c21eed04c67cefaaedc248ef16e5f6b293 Mon Sep 17 00:00:00 2001
+From: Biju Das <biju.das.jz@bp.renesas.com>
+Date: Tue, 25 Oct 2022 16:56:55 +0100
+Subject: can: rcar_canfd: rcar_canfd_handle_global_receive(): fix IRQ storm on global FIFO receive
+
+From: Biju Das <biju.das.jz@bp.renesas.com>
+
+commit 702de2c21eed04c67cefaaedc248ef16e5f6b293 upstream.
+
+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 <mkl@pengutronix.de>
+Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
+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 <mkl@pengutronix.de>
+[biju: removed gpriv from RCANFD_RFCC_RFIE macro]
+Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/net/can/rcar/rcar_canfd.c |    6 ++++--
+ 1 file changed, 4 insertions(+), 2 deletions(-)
+
+--- a/drivers/net/can/rcar/rcar_canfd.c
++++ b/drivers/net/can/rcar/rcar_canfd.c
+@@ -1079,7 +1079,7 @@ static irqreturn_t rcar_canfd_global_int
+       struct rcar_canfd_global *gpriv = dev_id;
+       struct net_device *ndev;
+       struct rcar_canfd_channel *priv;
+-      u32 sts, gerfl;
++      u32 sts, cc, gerfl;
+       u32 ch, ridx;
+ 
+       /* Global error interrupts still indicate a condition specific
+@@ -1097,7 +1097,9 @@ static irqreturn_t rcar_canfd_global_int
+ 
+               /* Handle Rx interrupts */
+               sts = rcar_canfd_read(priv->base, RCANFD_RFSTS(ridx));
+-              if (likely(sts & RCANFD_RFSTS_RFIF)) {
++              cc = rcar_canfd_read(priv->base, RCANFD_RFCC(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,

diff --git a/queue-4.19/series b/queue-4.19/series
index 84ef7bbccf092f7fcda571b5092d15bb96784eaa..6781abc1633590d4727e8a39648def181dbf5a76 100644 (file)
--- a/queue-4.19/series
+++ b/queue-4.19/series
@@ -75,3 +75,4 @@ alsa-aoa-fix-i2s-device-accounting.patch
 openvswitch-switch-from-warn-to-pr_warn.patch
 net-ehea-fix-possible-memory-leak-in-ehea_register_p.patch
 net-mlx5e-do-not-increment-esn-when-updating-ipsec-e.patch
+can-rcar_canfd-rcar_canfd_handle_global_receive-fix-irq-storm-on-global-fifo-receive.patch