This is a note to let you know that I've just added the patch titled can: esd_usb: Make use of can_change_state() and relocate checking skb for NULL to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: can-esd_usb-make-use-of-can_change_state-and-relocat.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit abd4a10e93b125f1e454e5d12e40c1ef40cc0a32 Author: Frank Jungclaus <frank.jungclaus@xxxxxx> Date: Thu Feb 16 20:04:49 2023 +0100 can: esd_usb: Make use of can_change_state() and relocate checking skb for NULL [ Upstream commit 9684b000a86299b5968fef8ffbf1484def37452a ] Start 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 <frank.jungclaus@xxxxxx> Link: [1] https://lore.kernel.org/all/CAMZ6RqKGBWe15aMkf8-QLf-cOQg99GQBebSm+1wEzTqHgvmNuw@xxxxxxxxxxxxxx/ Link: [2] https://lore.kernel.org/all/CAMZ6Rq+QBO1yTX_o6GV0yhdBj-RzZSRGWDZBS0fs7zbSTy4hmA@xxxxxxxxxxxxxx/ Link: https://lore.kernel.org/all/20230216190450.3901254-3-frank.jungclaus@xxxxxx Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/can/usb/esd_usb.c b/drivers/net/can/usb/esd_usb.c index 5e182fadd875e..578b25f873e58 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++; + } } }