[PATCH V1 3/6] can: flexcan: implement error passive state quirk
From: ZHU Yi (ST-FIR/ENG1-Zhu) <hidden>
Date: 2017-09-15 07:04:02
Subsystem:
can network drivers, the rest · Maintainers:
Marc Kleine-Budde, Vincent Mailhol, Linus Torvalds
From 3e5941000e3ecae9f0e97313a0513131234a9de8 Mon Sep 17 00:00:00 2001 From: Zhu Yi <redacted> Date: Thu, 31 Aug 2017 09:21:24 +0800 Subject: [PATCH V1 3/6] can: flexcan: implement error passive state quirk Add FLEXCAN_QUIRK_BROKEN_PERR_STATE for better description of the missing error passive interrupt quirk. Error interrupt flooding may happen if the broken error state quirk fix is enabled. For example, in case there is singled out node on the bus and the node sends a frame, then error interrupt flooding happens and will not stop because the node cannot go to bus off. The flooding will stop after another node connected to the bus again. If high bitrate configured on the low end system, then the flooding may causes performance issue, hence, this patch mitigates this by: 1. disable error interrupt upon error passive state transition 2. re-enable error interrupt upon error warning state transition 3. disable/enable error interrupt upon error active state transition depends on FLEXCAN_QUIRK_BROKEN_WERR_STATE In this way, the driver is still able to report correct state transitions without additional latency. When there are bus problems, flooding of error interrupts is limited to the number of frames required to change state from error warning to error passive if the core has [TR]WRN_INT connected (FLEXCAN_QUIRK_BROKEN_WERR_STATE is not enabled), otherwise, the flooding is limited to the number of frames required to change state from error active to error passive. Signed-off-by: Zhu Yi <redacted> Signed-off-by: Mark Jonas <redacted> Acked-by: Wolfgang Grandegger <redacted> --- drivers/net/can/flexcan.c | 75 +++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 66 insertions(+), 9 deletions(-)
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index e163c55..3817452 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c@@ -182,14 +182,14 @@ /* FLEXCAN hardware feature flags * * Below is some version info we got: - * SOC Version IP-Version Glitch- [TR]WRN_INT Memory err RTR re- - * Filter? connected? detection ception in MB - * MX25 FlexCAN2 03.00.00.00 no no no no - * MX28 FlexCAN2 03.00.04.00 yes yes no no - * MX35 FlexCAN2 03.00.00.00 no no no no - * MX53 FlexCAN2 03.00.00.00 yes no no no - * MX6s FlexCAN3 10.00.12.00 yes yes no yes - * VF610 FlexCAN3 ? no yes yes yes? + * SOC Version IP-Version Glitch- [TR]WRN_INT IRQ Err Memory err RTR re- + * Filter? connected? Passive detection ception in MB + * MX25 FlexCAN2 03.00.00.00 no no ? no no + * MX28 FlexCAN2 03.00.04.00 yes yes no no no + * MX35 FlexCAN2 03.00.00.00 no no ? no no + * MX53 FlexCAN2 03.00.00.00 yes no no no no + * MX6s FlexCAN3 10.00.12.00 yes yes no no yes + * VF610 FlexCAN3 ? no yes ? yes yes? * * Some SOCs do not have the RX_WARN & TX_WARN interrupt line connected. */
@@ -198,6 +198,7 @@ #define FLEXCAN_QUIRK_ENABLE_EACEN_RRS BIT(3) /* Enable EACEN and RRS bit in ctrl2 */ #define FLEXCAN_QUIRK_DISABLE_MECR BIT(4) /* Disable Memory error detection */ #define FLEXCAN_QUIRK_USE_OFF_TIMESTAMP BIT(5) /* Use timestamp based offloading */ +#define FLEXCAN_QUIRK_BROKEN_PERR_STATE BIT(6) /* No interrupt for error passive */ /* Structure of the message buffer */ struct flexcan_mb {
@@ -335,6 +336,22 @@ static inline void flexcan_write(u32 val, void __iomem *addr) } #endif +static inline void flexcan_error_irq_enable(const struct flexcan_priv *priv) +{ + struct flexcan_regs __iomem *regs = priv->regs; + u32 reg_ctrl = (priv->reg_ctrl_default | FLEXCAN_CTRL_ERR_MSK); + + flexcan_write(reg_ctrl, ®s->ctrl); +} + +static inline void flexcan_error_irq_disable(const struct flexcan_priv *priv) +{ + struct flexcan_regs __iomem *regs = priv->regs; + u32 reg_ctrl = (priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_MSK); + + flexcan_write(reg_ctrl, ®s->ctrl); +} + static inline int flexcan_transceiver_enable(const struct flexcan_priv *priv) { if (!priv->reg_xceiver)
@@ -713,6 +730,7 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id) struct flexcan_regs __iomem *regs = priv->regs; irqreturn_t handled = IRQ_NONE; u32 reg_iflag1, reg_esr; + enum can_state last_state = priv->can.state; reg_iflag1 = flexcan_read(®s->iflag1);
@@ -767,7 +785,8 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id) /* state change interrupt or broken error state quirk fix is enabled */ if ((reg_esr & FLEXCAN_ESR_ERR_STATE) || - (priv->devtype_data->quirks & FLEXCAN_QUIRK_BROKEN_WERR_STATE)) + (priv->devtype_data->quirks & (FLEXCAN_QUIRK_BROKEN_WERR_STATE | + FLEXCAN_QUIRK_BROKEN_PERR_STATE))) flexcan_irq_state(dev, reg_esr); /* bus error IRQ - handle if bus error reporting is activated */
@@ -775,6 +794,44 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id) (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) flexcan_irq_bus_err(dev, reg_esr); + /* availability of error interrupt among state transitions in case + * bus error reporting is de-activated and + * FLEXCAN_QUIRK_BROKEN_PERR_STATE is enabled: + * +--------------------------------------------------------------+ + * | +----------------------------------------------+ [stopped / | + * | | | sleeping] -+ + * +-+-> active <-> warning <-> passive -> bus off -+ + * ___________^^^^^^^^^^^^_______________________________ + * disabled(1) enabled disabled + * + * (1): enabled if FLEXCAN_QUIRK_BROKEN_WERR_STATE is enabled + */ + if ((last_state != priv->can.state) && + (priv->devtype_data->quirks & FLEXCAN_QUIRK_BROKEN_PERR_STATE) && + !(priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) { + switch (priv->can.state) { + case CAN_STATE_ERROR_ACTIVE: + if (priv->devtype_data->quirks & + FLEXCAN_QUIRK_BROKEN_WERR_STATE) + flexcan_error_irq_enable(priv); + else + flexcan_error_irq_disable(priv); + break; + + case CAN_STATE_ERROR_WARNING: + flexcan_error_irq_enable(priv); + break; + + case CAN_STATE_ERROR_PASSIVE: + case CAN_STATE_BUS_OFF: + flexcan_error_irq_disable(priv); + break; + + default: + break; + } + } + return handled; }
--
2.7.4