2023-02-14 16:02:49

by Frank Jungclaus

[permalink] [raw]
Subject: [PATCH v2 0/3] can: esd_usb: Some more preparation for supporting esd CAN-USB/3

Another small batch of patches to be seen as preparation for adding
support of the newly available esd CAN-USB/3 to esd_usb.c.

Due to some unresolved questions adding support for
CAN_CTRLMODE_BERR_REPORTING has been postponed to one of the future
patches.

*Resend of the whole series as v2 for easier handling.*
---
* Changelog *

v1:
Link: https://lore.kernel.org/all/[email protected]/
Link: https://lore.kernel.org/all/[email protected]/

v1 -> v2:

* [Patch v2 1/3]: No changes.

* [Patch v2 2/3]: Make use of can_change_state() and relocate testing
alloc_can_err_skb() for NULL to the end of esd_usb_rx_event(), to
have things like can_bus_off(), can_change_state() working even in
out of memory conditions.

* [Patch v2 3/3]: No changes. I will 'declare esd_usb_msg as an union
instead of a struct' in a separate follow-up patch.


Frank Jungclaus (3):
can: esd_usb: Improved behavior on esd CAN_ERROR_EXT event (1)
can: esd_usb: Improved behavior on esd CAN_ERROR_EXT event (2)
can: esd_usb: Improved decoding for ESD_EV_CAN_ERROR_EXT messages

drivers/net/can/usb/esd_usb.c | 70 ++++++++++++++++++++---------------
1 file changed, 40 insertions(+), 30 deletions(-)


base-commit: fa1d915a624f72b153a9ff9700232056758a2b6c
--
2.25.1



2023-02-14 16:03:50

by Frank Jungclaus

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Subject: [PATCH v2 1/3] can: esd_usb: Improved behavior on esd CAN_ERROR_EXT event (1)

Moved the supply for cf->data[3] (bit stream position of CAN error)
outside of the "switch (ecc & SJA1000_ECC_MASK){}"-statement, because
this position is independent of the error type.

Fixes: 96d8e90382dc ("can: Add driver for esd CAN-USB/2 device")
Signed-off-by: Frank Jungclaus <[email protected]>
---
drivers/net/can/usb/esd_usb.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/can/usb/esd_usb.c b/drivers/net/can/usb/esd_usb.c
index 42323f5e6f3a..5e182fadd875 100644
--- a/drivers/net/can/usb/esd_usb.c
+++ b/drivers/net/can/usb/esd_usb.c
@@ -286,7 +286,6 @@ static void esd_usb_rx_event(struct esd_usb_net_priv *priv,
cf->data[2] |= CAN_ERR_PROT_STUFF;
break;
default:
- cf->data[3] = ecc & SJA1000_ECC_SEG;
break;
}

@@ -294,6 +293,9 @@ static void esd_usb_rx_event(struct esd_usb_net_priv *priv,
if (!(ecc & SJA1000_ECC_DIR))
cf->data[2] |= CAN_ERR_PROT_TX;

+ /* Bit stream position in CAN frame as the error was detected */
+ cf->data[3] = ecc & SJA1000_ECC_SEG;
+
if (priv->can.state == CAN_STATE_ERROR_WARNING ||
priv->can.state == CAN_STATE_ERROR_PASSIVE) {
cf->data[1] = (txerr > rxerr) ?
--
2.25.1


2023-02-14 16:18:44

by Frank Jungclaus

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Subject: [PATCH v2 2/3] can: esd_usb: Improved behavior on esd CAN_ERROR_EXT event (2)

Started a rework initiated by Vincents remarks "You should not report
the greatest of txerr and rxerr but the one which actually increased."
[1] and "As far as I understand, those flags should be set only when
the threshold is reached" [2] .

Therefore make use of can_change_state() to (among others) set the
flags CAN_ERR_CRTL_[RT]X_WARNING and CAN_ERR_CRTL_[RT]X_PASSIVE,
maintain CAN statistic counters for error_warning, error_passive and
bus_off.

Relocate testing alloc_can_err_skb() for NULL to the end of
esd_usb_rx_event(), to have things like can_bus_off(),
can_change_state() working even in out of memory conditions.

Fixes: 96d8e90382dc ("can: Add driver for esd CAN-USB/2 device")
Signed-off-by: Frank Jungclaus <[email protected]>
Link: [1] https://lore.kernel.org/all/CAMZ6RqKGBWe15aMkf8-QLf-cOQg99GQBebSm+1wEzTqHgvmNuw@mail.gmail.com/
Link: [2] https://lore.kernel.org/all/CAMZ6Rq+QBO1yTX_o6GV0yhdBj-RzZSRGWDZBS0fs7zbSTy4hmA@mail.gmail.com/
---
drivers/net/can/usb/esd_usb.c | 50 +++++++++++++++++------------------
1 file changed, 25 insertions(+), 25 deletions(-)

diff --git a/drivers/net/can/usb/esd_usb.c b/drivers/net/can/usb/esd_usb.c
index 5e182fadd875..578b25f873e5 100644
--- a/drivers/net/can/usb/esd_usb.c
+++ b/drivers/net/can/usb/esd_usb.c
@@ -239,41 +239,42 @@ static void esd_usb_rx_event(struct esd_usb_net_priv *priv,
msg->msg.rx.dlc, state, ecc, rxerr, txerr);

skb = alloc_can_err_skb(priv->netdev, &cf);
- if (skb == NULL) {
- stats->rx_dropped++;
- return;
- }

if (state != priv->old_state) {
+ enum can_state tx_state, rx_state;
+ enum can_state new_state = CAN_STATE_ERROR_ACTIVE;
+
priv->old_state = state;

switch (state & ESD_BUSSTATE_MASK) {
case ESD_BUSSTATE_BUSOFF:
- priv->can.state = CAN_STATE_BUS_OFF;
- cf->can_id |= CAN_ERR_BUSOFF;
- priv->can.can_stats.bus_off++;
+ new_state = CAN_STATE_BUS_OFF;
can_bus_off(priv->netdev);
break;
case ESD_BUSSTATE_WARN:
- priv->can.state = CAN_STATE_ERROR_WARNING;
- priv->can.can_stats.error_warning++;
+ new_state = CAN_STATE_ERROR_WARNING;
break;
case ESD_BUSSTATE_ERRPASSIVE:
- priv->can.state = CAN_STATE_ERROR_PASSIVE;
- priv->can.can_stats.error_passive++;
+ new_state = CAN_STATE_ERROR_PASSIVE;
break;
default:
- priv->can.state = CAN_STATE_ERROR_ACTIVE;
+ new_state = CAN_STATE_ERROR_ACTIVE;
txerr = 0;
rxerr = 0;
break;
}
- } else {
+
+ if (new_state != priv->can.state) {
+ tx_state = (txerr >= rxerr) ? new_state : 0;
+ rx_state = (txerr <= rxerr) ? new_state : 0;
+ can_change_state(priv->netdev, cf,
+ tx_state, rx_state);
+ }
+ } else if (skb) {
priv->can.can_stats.bus_error++;
stats->rx_errors++;

- cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR |
- CAN_ERR_CNT;
+ cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;

switch (ecc & SJA1000_ECC_MASK) {
case SJA1000_ECC_BIT:
@@ -295,21 +296,20 @@ static void esd_usb_rx_event(struct esd_usb_net_priv *priv,

/* Bit stream position in CAN frame as the error was detected */
cf->data[3] = ecc & SJA1000_ECC_SEG;
-
- if (priv->can.state == CAN_STATE_ERROR_WARNING ||
- priv->can.state == CAN_STATE_ERROR_PASSIVE) {
- cf->data[1] = (txerr > rxerr) ?
- CAN_ERR_CRTL_TX_PASSIVE :
- CAN_ERR_CRTL_RX_PASSIVE;
- }
- cf->data[6] = txerr;
- cf->data[7] = rxerr;
}

priv->bec.txerr = txerr;
priv->bec.rxerr = rxerr;

- netif_rx(skb);
+ if (skb) {
+ cf->can_id |= CAN_ERR_CNT;
+ cf->data[6] = txerr;
+ cf->data[7] = rxerr;
+
+ netif_rx(skb);
+ } else {
+ stats->rx_dropped++;
+ }
}
}

--
2.25.1


2023-02-14 16:19:07

by Frank Jungclaus

[permalink] [raw]
Subject: [PATCH v2 3/3] can: esd_usb: Improved decoding for ESD_EV_CAN_ERROR_EXT messages

As suggested by Marc there now is a union plus a struct ev_can_err_ext
for easier decoding of an ESD_EV_CAN_ERROR_EXT event message (which
simply is a rx_msg with some dedicated data).

Suggested-by: Marc Kleine-Budde <[email protected]>
Link: https://lore.kernel.org/linux-can/[email protected]/
Signed-off-by: Frank Jungclaus <[email protected]>
---
drivers/net/can/usb/esd_usb.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/net/can/usb/esd_usb.c b/drivers/net/can/usb/esd_usb.c
index 578b25f873e5..55b36973952d 100644
--- a/drivers/net/can/usb/esd_usb.c
+++ b/drivers/net/can/usb/esd_usb.c
@@ -127,7 +127,15 @@ struct rx_msg {
u8 dlc;
__le32 ts;
__le32 id; /* upper 3 bits contain flags */
- u8 data[8];
+ union {
+ u8 data[8];
+ struct {
+ u8 status; /* CAN Controller Status */
+ u8 ecc; /* Error Capture Register */
+ u8 rec; /* RX Error Counter */
+ u8 tec; /* TX Error Counter */
+ } ev_can_err_ext; /* For ESD_EV_CAN_ERROR_EXT */
+ };
};

struct tx_msg {
@@ -229,10 +237,10 @@ static void esd_usb_rx_event(struct esd_usb_net_priv *priv,
u32 id = le32_to_cpu(msg->msg.rx.id) & ESD_IDMASK;

if (id == ESD_EV_CAN_ERROR_EXT) {
- u8 state = msg->msg.rx.data[0];
- u8 ecc = msg->msg.rx.data[1];
- u8 rxerr = msg->msg.rx.data[2];
- u8 txerr = msg->msg.rx.data[3];
+ u8 state = msg->msg.rx.ev_can_err_ext.status;
+ u8 ecc = msg->msg.rx.ev_can_err_ext.ecc;
+ u8 rxerr = msg->msg.rx.ev_can_err_ext.rec;
+ u8 txerr = msg->msg.rx.ev_can_err_ext.tec;

netdev_dbg(priv->netdev,
"CAN_ERR_EV_EXT: dlc=%#02x state=%02x ecc=%02x rec=%02x tec=%02x\n",
--
2.25.1


2023-02-15 10:20:21

by Marc Kleine-Budde

[permalink] [raw]
Subject: Re: [PATCH v2 0/3] can: esd_usb: Some more preparation for supporting esd CAN-USB/3

On 14.02.2023 17:02:20, Frank Jungclaus wrote:
> Another small batch of patches to be seen as preparation for adding
> support of the newly available esd CAN-USB/3 to esd_usb.c.
>
> Due to some unresolved questions adding support for
> CAN_CTRLMODE_BERR_REPORTING has been postponed to one of the future
> patches.
>
> *Resend of the whole series as v2 for easier handling.*

As Vincent pointed out in review of a completely different patch series,
bu this applies here, too:

| For the titles, please use imperative (e.g. add) instead of past tense
| (e.g. Added). This also applies to the description.

Further, the subject ob patches 1 and 2 can be improved a bit, e.g.
patch 1 could mention to move the SJA1000_ECC_SEG for a specific reason.

regards,
Marc

--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
Vertretung West/Dortmund | Phone: +49-231-2826-924 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |


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2023-02-16 18:36:33

by Frank Jungclaus

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Subject: Re: [PATCH v2 0/3] can: esd_usb: Some more preparation for supporting esd CAN-USB/3

On Wed, 2023-02-15 at 09:52 +0100, Marc Kleine-Budde wrote:
> On 14.02.2023 17:02:20, Frank Jungclaus wrote:
> > Another small batch of patches to be seen as preparation for adding
> > support of the newly available esd CAN-USB/3 to esd_usb.c.
> >
> > Due to some unresolved questions adding support for
> > CAN_CTRLMODE_BERR_REPORTING has been postponed to one of the future
> > patches.
> >
> > *Resend of the whole series as v2 for easier handling.*
>
> As Vincent pointed out in review of a completely different patch series,
> bu this applies here, too:
>
> > For the titles, please use imperative (e.g. add) instead of past tense
> > (e.g. Added). This also applies to the description.
>
> Further, the subject ob patches 1 and 2 can be improved a bit, e.g.
> patch 1 could mention to move the SJA1000_ECC_SEG for a specific reason.
>
> regards,
> Marc
>
Hi Marc,
ok, I'll resend this series as v3 soon to address your comments.

Regards, Frank