The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f58ac1adc76b5beda43c64ef359056077df4d93a Mon Sep 17 00:00:00 2001
From: Brian Silverman brian.silverman@bluerivertech.com Date: Mon, 29 Nov 2021 14:26:28 -0800 Subject: [PATCH] can: m_can: Disable and ignore ELO interrupt
With the design of this driver, this condition is often triggered. However, the counter that this interrupt indicates an overflow is never read either, so overflowing is harmless.
On my system, when a CAN bus starts flapping up and down, this locks up the whole system with lots of interrupts and printks.
Specifically, this interrupt indicates the CEL field of ECR has overflowed. All reads of ECR mask out CEL.
Fixes: e0d1f4816f2a ("can: m_can: add Bosch M_CAN controller support") Link: https://lore.kernel.org/all/20211129222628.7490-1-brian.silverman@bluerivert... Cc: stable@vger.kernel.org Signed-off-by: Brian Silverman brian.silverman@bluerivertech.com Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de
diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c index 2470c47b2e31..91be87c4f4d3 100644 --- a/drivers/net/can/m_can/m_can.c +++ b/drivers/net/can/m_can/m_can.c @@ -204,16 +204,16 @@ enum m_can_reg {
/* Interrupts for version 3.0.x */ #define IR_ERR_LEC_30X (IR_STE | IR_FOE | IR_ACKE | IR_BE | IR_CRCE) -#define IR_ERR_BUS_30X (IR_ERR_LEC_30X | IR_WDI | IR_ELO | IR_BEU | \ - IR_BEC | IR_TOO | IR_MRAF | IR_TSW | IR_TEFL | \ - IR_RF1L | IR_RF0L) +#define IR_ERR_BUS_30X (IR_ERR_LEC_30X | IR_WDI | IR_BEU | IR_BEC | \ + IR_TOO | IR_MRAF | IR_TSW | IR_TEFL | IR_RF1L | \ + IR_RF0L) #define IR_ERR_ALL_30X (IR_ERR_STATE | IR_ERR_BUS_30X)
/* Interrupts for version >= 3.1.x */ #define IR_ERR_LEC_31X (IR_PED | IR_PEA) -#define IR_ERR_BUS_31X (IR_ERR_LEC_31X | IR_WDI | IR_ELO | IR_BEU | \ - IR_BEC | IR_TOO | IR_MRAF | IR_TSW | IR_TEFL | \ - IR_RF1L | IR_RF0L) +#define IR_ERR_BUS_31X (IR_ERR_LEC_31X | IR_WDI | IR_BEU | IR_BEC | \ + IR_TOO | IR_MRAF | IR_TSW | IR_TEFL | IR_RF1L | \ + IR_RF0L) #define IR_ERR_ALL_31X (IR_ERR_STATE | IR_ERR_BUS_31X)
/* Interrupt Line Select (ILS) */ @@ -810,8 +810,6 @@ static void m_can_handle_other_err(struct net_device *dev, u32 irqstatus) { if (irqstatus & IR_WDI) netdev_err(dev, "Message RAM Watchdog event due to missing READY\n"); - if (irqstatus & IR_ELO) - netdev_err(dev, "Error Logging Overflow\n"); if (irqstatus & IR_BEU) netdev_err(dev, "Bit Error Uncorrected\n"); if (irqstatus & IR_BEC)