From 449052cfebf624b670faa040245d3feed770d22f Mon Sep 17 00:00:00 2001 From: Joakim Zhang Date: Thu, 18 Feb 2021 19:00:35 +0800 Subject: can: flexcan: assert FRZ bit in flexcan_chip_freeze() Assert HALT bit to enter freeze mode, there is a premise that FRZ bit is asserted. This patch asserts FRZ bit in flexcan_chip_freeze, although the reset value is 1b'1. This is a prepare patch, later patch will invoke flexcan_chip_freeze() to enter freeze mode, which polling freeze mode acknowledge. Fixes: b1aa1c7a2165b ("can: flexcan: fix transition from and to freeze mode in chip_{,un}freeze") Link: https://lore.kernel.org/r/20210218110037.16591-2-qiangqing.zhang@nxp.com Signed-off-by: Joakim Zhang Signed-off-by: Marc Kleine-Budde --- drivers/net/can/flexcan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/net/can/flexcan.c') diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index 971ada36e37f..ee2d4967d66a 100644 --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -701,7 +701,7 @@ static int flexcan_chip_freeze(struct flexcan_priv *priv) u32 reg; reg = priv->read(®s->mcr); - reg |= FLEXCAN_MCR_HALT; + reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT; priv->write(reg, ®s->mcr); while (timeout-- && !(priv->read(®s->mcr) & FLEXCAN_MCR_FRZ_ACK)) -- cgit v1.2.3 From ec15e27cc8904605846a354bb1f808ea1432f853 Mon Sep 17 00:00:00 2001 From: Joakim Zhang Date: Thu, 18 Feb 2021 19:00:36 +0800 Subject: can: flexcan: enable RX FIFO after FRZ/HALT valid RX FIFO enable failed could happen when do system reboot stress test: [ 0.303958] flexcan 5a8d0000.can: 5a8d0000.can supply xceiver not found, using dummy regulator [ 0.304281] flexcan 5a8d0000.can (unnamed net_device) (uninitialized): Could not enable RX FIFO, unsupported core [ 0.314640] flexcan 5a8d0000.can: registering netdev failed [ 0.320728] flexcan 5a8e0000.can: 5a8e0000.can supply xceiver not found, using dummy regulator [ 0.320991] flexcan 5a8e0000.can (unnamed net_device) (uninitialized): Could not enable RX FIFO, unsupported core [ 0.331360] flexcan 5a8e0000.can: registering netdev failed [ 0.337444] flexcan 5a8f0000.can: 5a8f0000.can supply xceiver not found, using dummy regulator [ 0.337716] flexcan 5a8f0000.can (unnamed net_device) (uninitialized): Could not enable RX FIFO, unsupported core [ 0.348117] flexcan 5a8f0000.can: registering netdev failed RX FIFO should be enabled after the FRZ/HALT are valid. But the current code enable RX FIFO and FRZ/HALT at the same time. Fixes: e955cead03117 ("CAN: Add Flexcan CAN controller driver") Link: https://lore.kernel.org/r/20210218110037.16591-3-qiangqing.zhang@nxp.com Signed-off-by: Joakim Zhang Signed-off-by: Marc Kleine-Budde --- drivers/net/can/flexcan.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'drivers/net/can/flexcan.c') diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index ee2d4967d66a..e66a51dbea0a 100644 --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -1865,10 +1865,14 @@ static int register_flexcandev(struct net_device *dev) if (err) goto out_chip_disable; - /* set freeze, halt and activate FIFO, restrict register access */ + /* set freeze, halt */ + err = flexcan_chip_freeze(priv); + if (err) + goto out_chip_disable; + + /* activate FIFO, restrict register access */ reg = priv->read(®s->mcr); - reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT | - FLEXCAN_MCR_FEN | FLEXCAN_MCR_SUPV; + reg |= FLEXCAN_MCR_FEN | FLEXCAN_MCR_SUPV; priv->write(reg, ®s->mcr); /* Currently we only support newer versions of this core -- cgit v1.2.3 From c63820045e2000f05657467a08715c18c9f490d9 Mon Sep 17 00:00:00 2001 From: Joakim Zhang Date: Thu, 18 Feb 2021 19:00:37 +0800 Subject: 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@nxp.com Signed-off-by: Joakim Zhang Signed-off-by: Marc Kleine-Budde --- drivers/net/can/flexcan.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'drivers/net/can/flexcan.c') 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 * -- cgit v1.2.3 From 47c5e474bc1e1061fb037d13b5000b38967eb070 Mon Sep 17 00:00:00 2001 From: Angelo Dureghello Date: Tue, 16 Mar 2021 00:15:10 +0100 Subject: can: flexcan: flexcan_chip_freeze(): fix chip freeze for missing bitrate For cases when flexcan is built-in, bitrate is still not set at registering. So flexcan_chip_freeze() generates: [ 1.860000] *** ZERO DIVIDE *** FORMAT=4 [ 1.860000] Current process id is 1 [ 1.860000] BAD KERNEL TRAP: 00000000 [ 1.860000] PC: [<402e70c8>] flexcan_chip_freeze+0x1a/0xa8 To allow chip freeze, using an hardcoded timeout when bitrate is still not set. Fixes: ec15e27cc890 ("can: flexcan: enable RX FIFO after FRZ/HALT valid") Link: https://lore.kernel.org/r/20210315231510.650593-1-angelo@kernel-space.org Signed-off-by: Angelo Dureghello [mkl: use if instead of ? operator] Signed-off-by: Marc Kleine-Budde --- drivers/net/can/flexcan.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'drivers/net/can/flexcan.c') diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index 134c05757a3b..57f3635ad8d7 100644 --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -697,9 +697,15 @@ static int flexcan_chip_disable(struct flexcan_priv *priv) static int flexcan_chip_freeze(struct flexcan_priv *priv) { struct flexcan_regs __iomem *regs = priv->regs; - unsigned int timeout = 1000 * 1000 * 10 / priv->can.bittiming.bitrate; + unsigned int timeout; + u32 bitrate = priv->can.bittiming.bitrate; u32 reg; + if (bitrate) + timeout = 1000 * 1000 * 10 / bitrate; + else + timeout = FLEXCAN_TIMEOUT_US / 10; + reg = priv->read(®s->mcr); reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT; priv->write(reg, ®s->mcr); -- cgit v1.2.3