flexcan: disable bus error interrupts for the i.MX28
Subsystems (3)
PATCH v2 1/1 flexcan: disable bus error interrupts for the i.MX28
Due to a bug in most Flexcan cores, the bus error interrupt needs to be enabled. Otherwise we don't get any error warning or passive interrupts. This is _not_ necessary for the i.MX28 and this patch disables bus error interrupts if "berr-reporting" is not requested. This avoids bus error flooding, which might harm, especially on low-end systems.
To handle such quirks of the Flexcan cores, a hardware feature flag has been introduced, also replacing the "hw_ver" variable. We got some version info about what Flexcan core version is available on what Freescale SOC which have been summarized as comment.
Changes since v1:
- add known version info and hw bugs as comment
- remove FLEXCAN_HAS_BROKEN_ERR_STATE for i.MX6Q
--- drivers/net/can/flexcan.c | 42 ++++++++++++++++++++++++++++++++---------- 1 files changed, 32 insertions(+), 10 deletions(-)
drivers/net/can/flexcan.c +32 -10
@@ -144,6 +144,23 @@#define FLEXCAN_MB_CODE_MASK (0xf0ffffff) +/* +* FLEXCAN hardware feature flags +* +* Below is some version info we got: +* SOC Version IP-Version Glitch- [TR]WRN_INT +* Filter? connected? +* MX25 FlexCAN2 03.00.00.00 no no +* MX28 FlexCAN2 03.00.04.00 yes yes +* MX35 FlexCAN2 03.00.00.00 no no +* MX53 FlexCAN2 03.00.00.00 yes no +* MX6s FlexCAN3 10.00.12.00 ? yes +* +* Some SOCs do not have the RX_WARN & TX_WARN interrupt line connected. +*/ +#define FLEXCAN_HAS_V10_FEATURES BIT(1)/* For core version >= 10 */ +#define FLEXCAN_HAS_BROKEN_ERR_STATE BIT(2)/* [TR]WRN_INT not connected */ +/* Structure of the message buffer */ struct flexcan_mb {u32 can_ctrl;
@@ -178,7 +195,7 @@ struct flexcan_regs { };struct flexcan_devtype_data { -u32 hw_ver;/* hardware controller version */ +u32 features;/* hardware controller features */ };struct flexcan_priv {
@@ -197,11 +214,11 @@ struct flexcan_priv { };static struct flexcan_devtype_data fsl_p1010_devtype_data = { - .hw_ver =3 , + .features =FLEXCAN_HAS_BROKEN_ERR_STATE , }; - +static struct flexcan_devtype_data fsl_imx28_devtype_data;static struct flexcan_devtype_data fsl_imx6q_devtype_data = { - .hw_ver =10 , + .features =FLEXCAN_HAS_V10_FEATURES , };static const struct can_bittiming_const flexcan_bittiming_const = {
@@ -741,15 +758,19 @@ static int flexcan_chip_start(struct net_device *dev)* enable tx and rx warning interrupt * enable bus off interrupt * (== FLEXCAN_CTRL_ERR_STATE) -* -* _note_: we enable the "error interrupt" -* (FLEXCAN_CTRL_ERR_MSK), too. Otherwise we don't get any -* warning or bus passive interrupts. */ reg_ctrl =flexcan_read (®s->ctrl); reg_ctrl &= ~FLEXCAN_CTRL_TSYN ; reg_ctrl |=FLEXCAN_CTRL_BOFF_REC |FLEXCAN_CTRL_LBUF | -FLEXCAN_CTRL_ERR_STATE |FLEXCAN_CTRL_ERR_MSK ; +FLEXCAN_CTRL_ERR_STATE ; +/* +* enable the "error interrupt" (FLEXCAN_CTRL_ERR_MSK), +* on most Flexcan cores, too. Otherwise we don't get +* any error warning or passive interrupts. +*/ +if (priv->devtype_data->features &FLEXCAN_HAS_BROKEN_ERR_STATE || + priv->can.ctrlmode &CAN_CTRLMODE_BERR_REPORTING ) + reg_ctrl |=FLEXCAN_CTRL_ERR_MSK ;/* save for later use */ priv->reg_ctrl_default = reg_ctrl;
@@ -772,7 +793,7 @@ static int flexcan_chip_start(struct net_device *dev)flexcan_write (0x0 , ®s->rx14mask);flexcan_write (0x0 , ®s->rx15mask); -if (priv->devtype_data->hw_ver >=10 ) +if (priv->devtype_data->features &FLEXCAN_HAS_V10_FEATURES )flexcan_write (0x0 , ®s->rxfgmask);flexcan_transceiver_switch (priv,1 );
@@ -954,6 +975,7 @@ static void __devexit unregister_flexcandev(struct net_device *dev)static const struct of_device_id flexcan_of_match[] = { { .compatible ="fsl,p1010-flexcan" , .data = &fsl_p1010_devtype_data, }, + { .compatible ="fsl,imx28-flexcan" , .data = &fsl_imx28_devtype_data, }, { .compatible ="fsl,imx6q-flexcan" , .data = &fsl_imx6q_devtype_data, }, {/* sentinel */ }, };
Signature · 1 line
1.7.7.6
Marc Kleine-Budde
maintainerQuoted 3 lines · Wolfgang Grandegger
Due to a bug in most Flexcan cores, the bus error interrupt needs to be enabled. Otherwise we don't get any error warning or passive interrupts. This is _not_ necessary for the i.MX28 and this patch
^^^ and i.MX6q
No need to resend the patch, I'll change this while applying the patch.
Quoted 9 lines
disables bus error interrupts if "berr-reporting" is not requested. This avoids bus error flooding, which might harm, especially on low-end systems.
To handle such quirks of the Flexcan cores, a hardware feature flag has been introduced, also replacing the "
hw_ver" variable. We got some version info about what Flexcan core version is available on what Freescale SOC which have been summarized as comment.
Quoted 4 lines
Changes since v1:
- add known version info and hw bugs as comment
- removeFLEXCAN_HAS_BROKEN_ERR_STATEfor i.MX6Q
From my point of view, this should go into linux-can.
Marc
Signature · 4 lines
Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
Marc Kleine-Budde
maintainerQuoted 12 lines · Wolfgang Grandegger
Due to a bug in most Flexcan cores, the bus error interrupt needs to be enabled. Otherwise we don't get any error warning or passive interrupts. This is _not_ necessary for the i.MX28 and this patch disables bus error interrupts if "berr-reporting" is not requested. This avoids bus error flooding, which might harm, especially on low-end systems.
To handle such quirks of the Flexcan cores, a hardware feature flag has been introduced, also replacing the "
hw_ver" variable. We got some version info about what Flexcan core version is available on what Freescale SOC which have been summarized as comment.
Quoted 4 lines
Changes since v1:
- add known version info and hw bugs as comment
- removeFLEXCAN_HAS_BROKEN_ERR_STATEfor i.MX6Q
David was quick in applying the v1 version of this patch into his tree directly. Wolfgang can you send an incremental patch? Please change the list of can cores, according to Dong Aisheng, the mx6 has a glitch filter, too.
regards, Marc
Signature · 4 lines
Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |