The patch below does not apply to the 4.9-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@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From c63820045e2000f05657467a08715c18c9f490d9 Mon Sep 17 00:00:00 2001 From: Joakim Zhang <qiangqing.zhang@xxxxxxx> Date: Thu, 18 Feb 2021 19:00:37 +0800 Subject: [PATCH] can: flexcan: invoke flexcan_chip_freeze() to enter freeze mode Invoke flexcan_chip_freeze() to enter freeze mode, since need poll freeze mode acknowledge. Fixes: e955cead03117 ("CAN: Add Flexcan CAN controller driver") Link: https://lore.kernel.org/r/20210218110037.16591-4-qiangqing.zhang@xxxxxxx Signed-off-by: Joakim Zhang <qiangqing.zhang@xxxxxxx> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index e66a51dbea0a..134c05757a3b 100644 --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -1480,10 +1480,13 @@ static int flexcan_chip_start(struct net_device *dev) flexcan_set_bittiming(dev); + /* set freeze, halt */ + err = flexcan_chip_freeze(priv); + if (err) + goto out_chip_disable; + /* MCR * - * enable freeze - * halt now * only supervisor access * enable warning int * enable individual RX masking @@ -1492,9 +1495,8 @@ static int flexcan_chip_start(struct net_device *dev) */ reg_mcr = priv->read(®s->mcr); reg_mcr &= ~FLEXCAN_MCR_MAXMB(0xff); - reg_mcr |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT | FLEXCAN_MCR_SUPV | - FLEXCAN_MCR_WRN_EN | FLEXCAN_MCR_IRMQ | FLEXCAN_MCR_IDAM_C | - FLEXCAN_MCR_MAXMB(priv->tx_mb_idx); + reg_mcr |= FLEXCAN_MCR_SUPV | FLEXCAN_MCR_WRN_EN | FLEXCAN_MCR_IRMQ | + FLEXCAN_MCR_IDAM_C | FLEXCAN_MCR_MAXMB(priv->tx_mb_idx); /* MCR *