On 3/14/19 9:38 AM, Wolfgang Grandegger wrote: > Hello, > > Am 14.03.19 um 15:04 schrieb Dan Murphy: >> Hello >> >> On 3/14/19 2:26 AM, Wolfgang Grandegger wrote: >>> Hello Dan, >>> >>> we are close... >>> >>> Am 13.03.19 um 17:26 schrieb Dan Murphy: >>>> Create a m_can platform framework that peripherial >>>> devices can register to and use common code and register sets. >>>> The peripherial devices may provide read/write and configuration >>>> support of the IP. >>>> >>>> Signed-off-by: Dan Murphy <[email protected]> >>>> --- >>>> >>>> v9 - Added back the CSR clearing as this is needed for TCAN device, fixed >>>> clean >>>> function to clean index for version > 30, removed extra skb free and fixed >>>> work >>>> handler to handle FIFO full for perpheral devices - >>>> https://lore.kernel.org/patchwork/patch/1050120/ >>>> >>>> v8 - Added a clean function for the tx_skb, cleaned up skb on BUS_OFF and >>>> on xmit >>>> BUSY - https://lore.kernel.org/patchwork/patch/1047980/ >>>> v7 - Fixed remaining new checkpatch issues, removed CSR setting, fixed tx >>>> hard >>>> start function to return tx_busy, and renamed device callbacks - >>>> https://lore.kernel.org/patchwork/patch/1047220/ >>>> v6 - Squashed platform patch to this patch for bissectablity, fixed coding >>>> style >>>> issues, updated Kconfig help, placed mcan reg offsets back into c file, >>>> renamed >>>> priv->skb to priv->tx_skb and cleared perp interrupts at ISR start - >>>> Patch 1 comments - https://lore.kernel.org/patchwork/patch/1042446/ >>>> Patch 2 comments - https://lore.kernel.org/patchwork/patch/1042442/ >>>> >>>> drivers/net/can/m_can/Kconfig | 13 +- >>>> drivers/net/can/m_can/Makefile | 1 + >>>> drivers/net/can/m_can/m_can.c | 733 +++++++++++++------------ >>>> drivers/net/can/m_can/m_can.h | 110 ++++ >>>> drivers/net/can/m_can/m_can_platform.c | 202 +++++++ >>>> 5 files changed, 714 insertions(+), 345 deletions(-) >>>> create mode 100644 drivers/net/can/m_can/m_can.h >>>> create mode 100644 drivers/net/can/m_can/m_can_platform.c >>>> >>>> diff --git a/drivers/net/can/m_can/Kconfig b/drivers/net/can/m_can/Kconfig >>>> index 04f20dd39007..f7119fd72df4 100644 >>>> --- a/drivers/net/can/m_can/Kconfig >>>> +++ b/drivers/net/can/m_can/Kconfig >>>> @@ -1,5 +1,14 @@ >>>> config CAN_M_CAN >>>> + tristate "Bosch M_CAN support" >>>> + ---help--- >>>> + Say Y here if you want support for Bosch M_CAN controller framework. >>>> + This is common support for devices that embed the Bosch M_CAN IP. >>>> + >>>> +config CAN_M_CAN_PLATFORM >>>> + tristate "Bosch M_CAN support for io-mapped devices" >>>> depends on HAS_IOMEM >>>> - tristate "Bosch M_CAN devices" >>>> + depends on CAN_M_CAN >>>> ---help--- >>>> - Say Y here if you want to support for Bosch M_CAN controller. >>>> + Say Y here if you want support for IO Mapped Bosch M_CAN controller. >>>> + This support is for devices that have the Bosch M_CAN controller >>>> + IP embedded into the device and the IP is IO Mapped to the processor. >>>> diff --git a/drivers/net/can/m_can/Makefile >>>> b/drivers/net/can/m_can/Makefile >>>> index 8bbd7f24f5be..057bbcdb3c74 100644 >>>> --- a/drivers/net/can/m_can/Makefile >>>> +++ b/drivers/net/can/m_can/Makefile >>>> @@ -3,3 +3,4 @@ >>>> # >>>> >>>> obj-$(CONFIG_CAN_M_CAN) += m_can.o >>>> +obj-$(CONFIG_CAN_M_CAN_PLATFORM) += m_can_platform.o >>>> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c >>>> index 9b449400376b..56336aefc567 100644 >>>> --- a/drivers/net/can/m_can/m_can.c >>>> +++ b/drivers/net/can/m_can/m_can.c > ... snip ... > >>>> +static netdev_tx_t m_can_start_xmit(struct sk_buff *skb, >>>> + struct net_device *dev) >>>> +{ >>>> + struct m_can_priv *priv = netdev_priv(dev); >>>> + >>>> + if (can_dropped_invalid_skb(dev, skb)) >>>> + return NETDEV_TX_OK; >>>> + >>>> + if (priv->is_peripherial) { >>>> + if (priv->tx_skb) { >>>> + netdev_err(dev, "hard_xmit called while tx busy\n"); >>>> + return NETDEV_TX_BUSY; >>>> + } >>>> + >>>> + if (priv->can.state == CAN_STATE_BUS_OFF) { >>>> + m_can_clean(dev); >>>> + } else { >>>> + priv->tx_skb = skb; >>>> + queue_work(priv->tx_wq, &priv->tx_work); >>> >>> You removed "netif_stop_queue(cdev->net)" here. Does that work with just >>> *one* "tx_skb"? I think you need an array then!? I'm afraid, this will >>> require quite some changes and you should also measure the benefit of >>> queuing outgoing messages first. For the time being, it would be fine >>> for me to stop the queue here and add an appropriate comment. >>> >> >> Yes I removed this in favor of allowing the work handler to stop the queue. >> >> If the version is < 30 then the queue is stopped immediately. If the >> version > 30 then the queue is >> only stopped if FIFO is full. > > Yes, and the next call to m_can_start_xmit() will probably return with > NETDEV_TX_BUSY. You should at least add a "netif_stop_queue(cdev->net)" > before returning NETDEV_TX_BUSY, otherwice the upper layer will retry > immediately resulting in high CPU load. Anyway, the purpose of this > return code is to signal errors/bugs in the start/stop flow control: >
Ack > https://elixir.bootlin.com/linux/latest/source/Documentation/networking/netdevices.txt#L81 > >> >> I did see the message "tcan4x5x spi1.0 can0: hard_xmit called while tx busy" >> more with no gap and no polling in the cangen request. > > You usually should never see that message. > >> >>> BTW, how big is the FIFO size on your system: >>> >> >> This value is set to 1. >> >>> tx_fifo_size = mram_config_vals[7]; > > Then I'm surprised that you see "hard_xmit called while tx busy" at all. > Are you sure that "cdev->version" is 32 on the tcan4x5? > tcan4x5x spi1.0 can0: Version of M_CAN is 32 > Wolfgang > -- ------------------ Dan Murphy
