diff options
Diffstat (limited to 'target/linux/layerscape/patches-5.4/802-can-0026-can-flexcan-fix-deadlock-when-using-self-wakeup.patch')
| -rw-r--r-- | target/linux/layerscape/patches-5.4/802-can-0026-can-flexcan-fix-deadlock-when-using-self-wakeup.patch | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/target/linux/layerscape/patches-5.4/802-can-0026-can-flexcan-fix-deadlock-when-using-self-wakeup.patch b/target/linux/layerscape/patches-5.4/802-can-0026-can-flexcan-fix-deadlock-when-using-self-wakeup.patch new file mode 100644 index 0000000000..a771395701 --- /dev/null +++ b/target/linux/layerscape/patches-5.4/802-can-0026-can-flexcan-fix-deadlock-when-using-self-wakeup.patch @@ -0,0 +1,62 @@ +From 59876225748221d7ebbdb9c892a2086420ddd80d Mon Sep 17 00:00:00 2001 +From: Sean Nyekjaer <sean@geanix.com> +Date: Thu, 14 Nov 2019 19:56:28 +0800 +Subject: [PATCH] can: flexcan: fix deadlock when using self wakeup + +When suspending, when there is still can traffic on the interfaces the +flexcan immediately wakes the platform again. As it should :-). But it +throws this error msg: +[ 3169.378661] PM: noirq suspend of devices failed + +On the way down to suspend the interface that throws the error message does +call flexcan_suspend but fails to call flexcan_noirq_suspend. That means the +flexcan_enter_stop_mode is called, but on the way out of suspend the driver +only calls flexcan_resume and skips flexcan_noirq_resume, thus it doesn't call +flexcan_exit_stop_mode. This leaves the flexcan in stop mode, and with the +current driver it can't recover from this even with a soft reboot, it requires +a hard reboot. + +This patch can fix deadlock when using self wakeup, it happenes to be +able to fix another issue that frames out-of-order in first IRQ handler +run after wakeup. + +In wakeup case, after system resume, frames received out-of-order,the +problem is wakeup latency from frame reception to IRQ handler is much +bigger than the counter overflow. This means it's impossible to sort the +CAN frames by timestamp. The reason is that controller exits stop mode +during noirq resume, then it can receive the frame immediately. If +noirq reusme stage consumes much time, it will extend interrupt response +time. + +Fixes: de3578c198c6 ("can: flexcan: add self wakeup support") +Signed-off-by: Sean Nyekjaer <sean@geanix.com> +Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com> +--- + drivers/net/can/flexcan.c | 9 +++++++-- + 1 file changed, 7 insertions(+), 2 deletions(-) + +--- a/drivers/net/can/flexcan.c ++++ b/drivers/net/can/flexcan.c +@@ -137,8 +137,7 @@ + (FLEXCAN_ESR_ERR_BUS | FLEXCAN_ESR_ERR_STATE) + #define FLEXCAN_ESR_ALL_INT \ + (FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | \ +- FLEXCAN_ESR_BOFF_INT | FLEXCAN_ESR_ERR_INT | \ +- FLEXCAN_ESR_WAK_INT) ++ FLEXCAN_ESR_BOFF_INT | FLEXCAN_ESR_ERR_INT) + + /* FLEXCAN Bit Timing register (CBT) bits */ + #define FLEXCAN_CBT_BTF BIT(31) +@@ -1055,6 +1054,12 @@ static irqreturn_t flexcan_irq(int irq, + + reg_esr = priv->read(®s->esr); + ++ /* ACK wakeup interrupt */ ++ if (reg_esr & FLEXCAN_ESR_WAK_INT) { ++ handled = IRQ_HANDLED; ++ priv->write(reg_esr & FLEXCAN_ESR_WAK_INT, ®s->esr); ++ } ++ + /* ACK all bus error and state change IRQ sources */ + if (reg_esr & FLEXCAN_ESR_ALL_INT) { + handled = IRQ_HANDLED; |