From: Vincent Mailhol <vincent.mailhol@gmail.com>
To: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Cc: linux-kernel@vger.kernel.org,
Alexandre Torgue <alexandre.torgue@foss.st.com>,
Amarula patchwork <linux-amarula@amarulasolutions.com>,
Marc Kleine-Budde <mkl@pengutronix.de>,
michael@amarulasolutions.com, Dario Binacchi <dariobin@libero.it>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Wolfgang Grandegger <wg@grandegger.com>,
linux-can@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [RFC PATCH v2 4/4] can: bxcan: add support for ST bxCAN controller
Date: Sat, 27 Aug 2022 06:56:42 +0900 [thread overview]
Message-ID: <CAMZ6RqKQJZBVOSU7oA3AGSRG11vxdysAyRotHavUzsVRuM28Kw@mail.gmail.com> (raw)
In-Reply-To: <20220820082936.686924-5-dario.binacchi@amarulasolutions.com>
On Sat. 20 Aug. 2022 à 17:32, Dario Binacchi
<dario.binacchi@amarulasolutions.com> a écrit :
> Add support for the basic extended CAN controller (bxCAN) found in many
> low- to middle-end STM32 SoCs. It supports the Basic Extended CAN
> protocol versions 2.0A and B with a maximum bit rate of 1 Mbit/s.
>
> The controller supports two channels (CAN1 as master and CAN2 as slave)
> and the driver can enable either or both of the channels. They share
> some of the required logic (e. g. clocks and filters), and that means
> you cannot use the slave CAN without enabling some hardware resources
> managed by the master CAN.
>
> Each channel has 3 transmit mailboxes, 2 receive FIFOs with 3 stages and
> 28 scalable filter banks.
> It also manages 4 dedicated interrupt vectors:
> - transmit interrupt
> - FIFO 0 receive interrupt
> - FIFO 1 receive interrupt
> - status change error interrupt
>
> Driver uses all 3 available mailboxes for transmission and FIFO 0 for
> reception. Rx filter rules are configured to the minimum. They accept
> all messages and assign filter 0 to CAN1 and filter 14 to CAN2 in
> identifier mask mode with 32 bits width. It enables and uses transmit,
> receive buffers for FIFO 0 and error and status change interrupts.
>
> Signed-off-by: Dario Binacchi <dariobin@libero.it>
> Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
>
> ---
(...)
> +static void bxcan_handle_state_change(struct net_device *ndev, u32 esr)
> +{
> + struct bxcan_priv *priv = netdev_priv(ndev);
> + struct net_device_stats *stats = &ndev->stats;
> + enum can_state new_state = priv->can.state;
> + struct can_berr_counter bec;
> + enum can_state rx_state, tx_state;
> + struct sk_buff *skb;
> + struct can_frame *cf;
> +
> + /* Early exit if no error flag is set */
> + if (!(esr & (BXCAN_ESR_EWGF | BXCAN_ESR_EPVF | BXCAN_ESR_BOFF)))
> + return;
> +
> + bec.txerr = BXCAN_TEC(esr);
> + bec.rxerr = BXCAN_REC(esr);
> +
> + if (esr & BXCAN_ESR_BOFF)
> + new_state = CAN_STATE_BUS_OFF;
> + else if (esr & BXCAN_ESR_EPVF)
> + new_state = CAN_STATE_ERROR_PASSIVE;
> + else if (esr & BXCAN_ESR_EWGF)
> + new_state = CAN_STATE_ERROR_WARNING;
> +
> + /* state hasn't changed */
> + if (unlikely(new_state == priv->can.state))
> + return;
> +
> + skb = alloc_can_err_skb(ndev, &cf);
> + if (unlikely(!skb))
> + return;
> +
> + tx_state = bec.txerr >= bec.rxerr ? new_state : 0;
> + rx_state = bec.txerr <= bec.rxerr ? new_state : 0;
> + can_change_state(ndev, cf, tx_state, rx_state);
> +
> + if (new_state == CAN_STATE_BUS_OFF)
> + can_bus_off(ndev);
> +
> + stats->rx_bytes += cf->len;
Please do not increment the stats if the frame is remote (c.f. CAN_RTR_FLAG).
> + stats->rx_packets++;
> + netif_rx(skb);
> +}
Yours sincerely,
Vincent Mailhol
prev parent reply other threads:[~2022-08-26 21:57 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-20 8:29 [RFC PATCH v2 0/4] can: bxcan: add support for ST bxCAN controller Dario Binacchi
2022-08-20 8:29 ` [RFC PATCH v2 1/4] dt-bindings: net: can: add STM32 bxcan DT bindings Dario Binacchi
2022-08-23 13:41 ` Krzysztof Kozlowski
2022-08-26 7:12 ` Dario Binacchi
2022-08-25 21:12 ` Rob Herring
2022-08-26 7:27 ` Dario Binacchi
2022-08-31 22:05 ` Rob Herring
2022-08-20 8:29 ` [RFC PATCH v2 2/4] ARM: dts: stm32: add CAN support on stm32f429 Dario Binacchi
2022-08-20 8:29 ` [RFC PATCH v2 3/4] ARM: dts: stm32: add pin map for CAN controller on stm32f4 Dario Binacchi
2022-08-23 13:43 ` Krzysztof Kozlowski
2022-08-26 6:32 ` Dario Binacchi
2022-08-20 8:29 ` [RFC PATCH v2 4/4] can: bxcan: add support for ST bxCAN controller Dario Binacchi
2022-08-26 21:56 ` Vincent Mailhol [this message]
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