2019-09-26 10:58:52

by Jeroen Hofstee

[permalink] [raw]
Subject: [PATCH 1/2] can: D_CAN: perform a sofware reset on open

When the C_CAN interface is closed it is put in power down mode, but
does not reset the error counters / state. So reset the D_CAN on open,
so the reported state and the actual state match.

According to [1], the C_CAN module doesn't have the software reset.

[1] http://www.bosch-semiconductors.com/media/ip_modules/pdf_2/c_can_fd8/users_manual_c_can_fd8_r210_1.pdf

Signed-off-by: Jeroen Hofstee <[email protected]>
---
drivers/net/can/c_can/c_can.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)

diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index 606b7d8ffe13..502a181d02e7 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -52,6 +52,7 @@
#define CONTROL_EX_PDR BIT(8)

/* control register */
+#define CONTROL_SWR BIT(15)
#define CONTROL_TEST BIT(7)
#define CONTROL_CCE BIT(6)
#define CONTROL_DISABLE_AR BIT(5)
@@ -569,6 +570,26 @@ static void c_can_configure_msg_objects(struct net_device *dev)
IF_MCONT_RCV_EOB);
}

+static int software_reset(struct net_device *dev)
+{
+ struct c_can_priv *priv = netdev_priv(dev);
+ int retry = 0;
+
+ if (priv->type != BOSCH_D_CAN)
+ return 0;
+
+ priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_SWR | CONTROL_INIT);
+ while (priv->read_reg(priv, C_CAN_CTRL_REG) & CONTROL_SWR) {
+ msleep(20);
+ if (retry++ > 100) {
+ netdev_err(dev, "CCTRL: software reset failed\n");
+ return -EIO;
+ }
+ }
+
+ return 0;
+}
+
/*
* Configure C_CAN chip:
* - enable/disable auto-retransmission
@@ -578,6 +599,11 @@ static void c_can_configure_msg_objects(struct net_device *dev)
static int c_can_chip_config(struct net_device *dev)
{
struct c_can_priv *priv = netdev_priv(dev);
+ int err;
+
+ err = software_reset(dev);
+ if (err)
+ return err;

/* enable automatic retransmission */
priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_ENABLE_AR);
--
2.17.1


2019-10-01 13:40:58

by Kurt Van Dijck

[permalink] [raw]
Subject: Re: [PATCH 1/2] can: D_CAN: perform a sofware reset on open

On do, 26 sep 2019 08:50:44 +0000, Jeroen Hofstee wrote:
> When the C_CAN interface is closed it is put in power down mode, but
> does not reset the error counters / state. So reset the D_CAN on open,
> so the reported state and the actual state match.
>
> According to [1], the C_CAN module doesn't have the software reset.
>
> [1] http://www.bosch-semiconductors.com/media/ip_modules/pdf_2/c_can_fd8/users_manual_c_can_fd8_r210_1.pdf
>
> Signed-off-by: Jeroen Hofstee <[email protected]>

I observed no problems after applying the patch.

Tested-by: Kurt Van Dijck <[email protected]>

2019-10-01 14:36:28

by Marc Kleine-Budde

[permalink] [raw]
Subject: Re: [PATCH 1/2] can: D_CAN: perform a sofware reset on open

On 9/26/19 10:50 AM, Jeroen Hofstee wrote:
> When the C_CAN interface is closed it is put in power down mode, but
> does not reset the error counters / state. So reset the D_CAN on open,
> so the reported state and the actual state match.
>
> According to [1], the C_CAN module doesn't have the software reset.
>
> [1] http://www.bosch-semiconductors.com/media/ip_modules/pdf_2/c_can_fd8/users_manual_c_can_fd8_r210_1.pdf
>
> Signed-off-by: Jeroen Hofstee <[email protected]>
> ---
> drivers/net/can/c_can/c_can.c | 26 ++++++++++++++++++++++++++
> 1 file changed, 26 insertions(+)
>
> diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
> index 606b7d8ffe13..502a181d02e7 100644
> --- a/drivers/net/can/c_can/c_can.c
> +++ b/drivers/net/can/c_can/c_can.c
> @@ -52,6 +52,7 @@
> #define CONTROL_EX_PDR BIT(8)
>
> /* control register */
> +#define CONTROL_SWR BIT(15)
> #define CONTROL_TEST BIT(7)
> #define CONTROL_CCE BIT(6)
> #define CONTROL_DISABLE_AR BIT(5)
> @@ -569,6 +570,26 @@ static void c_can_configure_msg_objects(struct net_device *dev)
> IF_MCONT_RCV_EOB);
> }
>
> +static int software_reset(struct net_device *dev)

Please add the common prefix "c_can_" to the function

> +{
> + struct c_can_priv *priv = netdev_priv(dev);
> + int retry = 0;
> +
> + if (priv->type != BOSCH_D_CAN)
> + return 0;
> +
> + priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_SWR | CONTROL_INIT);
> + while (priv->read_reg(priv, C_CAN_CTRL_REG) & CONTROL_SWR) {
> + msleep(20);
> + if (retry++ > 100) {
> + netdev_err(dev, "CCTRL: software reset failed\n");
> + return -EIO;
> + }
> + }
> +
> + return 0;
> +}
> +
> /*
> * Configure C_CAN chip:
> * - enable/disable auto-retransmission
> @@ -578,6 +599,11 @@ static void c_can_configure_msg_objects(struct net_device *dev)
> static int c_can_chip_config(struct net_device *dev)
> {
> struct c_can_priv *priv = netdev_priv(dev);
> + int err;
> +
> + err = software_reset(dev);
> + if (err)
> + return err;
>
> /* enable automatic retransmission */
> priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_ENABLE_AR);
>

Marc

--
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 |


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2019-10-02 04:57:35

by Jeroen Hofstee

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Subject: Re: [PATCH 1/2] can: D_CAN: perform a sofware reset on open

Hello Marc,

On 10/1/19 4:32 PM, Marc Kleine-Budde wrote:
> On 9/26/19 10:50 AM, Jeroen Hofstee wrote:
>> When the C_CAN interface is closed it is put in power down mode, but
>> does not reset the error counters / state. So reset the D_CAN on open,
>> so the reported state and the actual state match.
>>
>> According to [1], the C_CAN module doesn't have the software reset.
>>
>> [1] http://www.bosch-semiconductors.com/media/ip_modules/pdf_2/c_can_fd8/users_manual_c_can_fd8_r210_1.pdf
>>
>> Signed-off-by: Jeroen Hofstee <[email protected]>
>> ---
>> drivers/net/can/c_can/c_can.c | 26 ++++++++++++++++++++++++++
>> 1 file changed, 26 insertions(+)
>>
>> diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
>> index 606b7d8ffe13..502a181d02e7 100644
>> --- a/drivers/net/can/c_can/c_can.c
>> +++ b/drivers/net/can/c_can/c_can.c
>> @@ -52,6 +52,7 @@
>> #define CONTROL_EX_PDR BIT(8)
>>
>> /* control register */
>> +#define CONTROL_SWR BIT(15)
>> #define CONTROL_TEST BIT(7)
>> #define CONTROL_CCE BIT(6)
>> #define CONTROL_DISABLE_AR BIT(5)
>> @@ -569,6 +570,26 @@ static void c_can_configure_msg_objects(struct net_device *dev)
>> IF_MCONT_RCV_EOB);
>> }
>>
>> +static int software_reset(struct net_device *dev)
> Please add the common prefix "c_can_" to the function

Fine with me, I did sent a v2.

Regards,
Jeroen