This is a note to let you know that I've just added the patch titled can: m_can: Disable and ignore ELO interrupt to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: can-m_can-disable-and-ignore-elo-interrupt.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From f58ac1adc76b5beda43c64ef359056077df4d93a Mon Sep 17 00:00:00 2001 From: Brian Silverman <brian.silverman@xxxxxxxxxxxxxxxxx> Date: Mon, 29 Nov 2021 14:26:28 -0800 Subject: can: m_can: Disable and ignore ELO interrupt From: Brian Silverman <brian.silverman@xxxxxxxxxxxxxxxxx> commit f58ac1adc76b5beda43c64ef359056077df4d93a upstream. 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@xxxxxxxxxxxxxxxxx Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Brian Silverman <brian.silverman@xxxxxxxxxxxxxxxxx> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/can/m_can/m_can.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) --- a/drivers/net/can/m_can/m_can.c +++ b/drivers/net/can/m_can/m_can.c @@ -206,15 +206,15 @@ 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) */ @@ -751,8 +751,6 @@ static void m_can_handle_other_err(struc { 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) Patches currently in stable-queue which might be from brian.silverman@xxxxxxxxxxxxxxxxx are queue-5.4/can-m_can-disable-and-ignore-elo-interrupt.patch