kernel/linux.git/drivers/net/can/m_can, branch linux-6.9.y

can: tcan4x5x: support resuming from rx interrupt signal

2024-02-14T12:44:02+00:00

Implement the "wakeup-source" device tree property, so the chip is left running when suspending, and its rx interrupt is used as a wakeup source to resume operation. Signed-off-by: Martin Hundebøll Signed-off-by: Marc Kleine-Budde

can: m_can: allow keeping the transceiver running in suspend

2024-02-14T12:44:02+00:00

Add a flag to the device class structure that leaves the chip in a running state with rx interrupt enabled, so that an m_can device driver can configure and use the interrupt as a wakeup source. Signed-off-by: Martin Hundebøll Signed-off-by: Marc Kleine-Budde

can: m_can: remove redundant check for pm_clock_support

2024-02-14T10:24:30+00:00

m_can_clk_start() already skip starting the clock when clock support is disabled, remove the redundant check in m_can_class_register(). This also solves the imbalance with m_can_clk_stop() that is called afterward in the same function before the return. Signed-off-by: Francesco Dolcini Reviewed-by: Markus Schneider-Pargmann Link: https://lore.kernel.org/all/20240104235723.46931-1-francesco@dolcini.it [mkl: rebased to net-next/main] Signed-off-by: Marc Kleine-Budde

can: m_can: Implement transmit submission coalescing

2024-02-12T16:02:45+00:00

m_can supports submitting multiple transmits with one register write. This is an interesting option to reduce the number of SPI transfers for peripheral chips. The m_can_tx_op is extended with a bool that signals if it is the last transmission and the submit should be executed immediately. The worker then writes the skb to the FIFO and submits it only if the submit bool is set. If it isn't set, the worker will write the next skb which is waiting in the workqueue to the FIFO, etc. Signed-off-by: Markus Schneider-Pargmann Link: https://lore.kernel.org/all/20240207093220.2681425-15-msp@baylibre.com Signed-off-by: Marc Kleine-Budde

can: m_can: Implement BQL

2024-02-12T16:02:45+00:00

Implement byte queue limiting in preparation for the use of xmit_more(). Signed-off-by: Markus Schneider-Pargmann Link: https://lore.kernel.org/all/20240207093220.2681425-14-msp@baylibre.com Signed-off-by: Marc Kleine-Budde

can: m_can: Use tx_fifo_in_flight for netif_queue control

2024-02-12T16:02:44+00:00

The network queue is currently always stopped in start_xmit and continued in the interrupt handler. This is not possible anymore if we want to keep multiple transmits in flight in parallel. Use the previously introduced tx_fifo_in_flight counter to control the network queue instead. This has the benefit of not needing to ask the hardware about fifo status. This patch stops the network queue in start_xmit if the number of transmits in flight reaches the size of the fifo and wakes up the queue from the interrupt handler once the transmits in flight drops below the fifo size. This means any skbs over the limit will be rejected immediately in start_xmit (it shouldn't be possible at all to reach that state anyways). The maximum number of transmits in flight is the size of the fifo. Signed-off-by: Markus Schneider-Pargmann Link: https://lore.kernel.org/all/20240207093220.2681425-13-msp@baylibre.com Signed-off-by: Marc Kleine-Budde

can: m_can: Introduce a tx_fifo_in_flight counter

2024-02-12T16:02:44+00:00

Keep track of the number of transmits in flight. This patch prepares the driver to control the network interface queue based on this counter. By itself this counter be implemented with an atomic, but as we need to do other things in the critical sections later I am using a spinlock instead. Signed-off-by: Markus Schneider-Pargmann Link: https://lore.kernel.org/all/20240207093220.2681425-12-msp@baylibre.com Signed-off-by: Marc Kleine-Budde

can: m_can: Use the workqueue as queue

2024-02-12T16:02:44+00:00

The current implementation uses the workqueue for peripheral chips to submit work. Only a single work item is queued and used at any time. To be able to keep more than one transmit in flight at a time, prepare the workqueue to support multiple transmits at the same time. Each work item now has a separate storage for a skb and a pointer to cdev. This assures that each workitem can be processed individually. The workqueue is replaced by an ordered workqueue which makes sure that only a single worker processes the items queued on the workqueue. Also items are ordered by the order they were enqueued. This removes most of the concurrency the workqueue normally offers. It is not necessary for this driver. The cleanup functions have to be adopted a bit to handle this new mechanism. Signed-off-by: Markus Schneider-Pargmann Link: https://lore.kernel.org/all/20240207093220.2681425-11-msp@baylibre.com Signed-off-by: Marc Kleine-Budde

can: m_can: Cache tx putidx

2024-02-12T16:02:44+00:00

m_can_tx_handler is the only place where data is written to the tx fifo. We can calculate the putidx in the driver code here to avoid the dependency on the txfqs register. Signed-off-by: Markus Schneider-Pargmann Reviewed-by: Simon Horman Link: https://lore.kernel.org/all/20240207093220.2681425-10-msp@baylibre.com Signed-off-by: Marc Kleine-Budde

can: m_can: Use u32 for putidx

2024-02-12T16:02:44+00:00

putidx is not an integer normally, it is an unsigned field used in hardware registers. Use a u32 for it. Signed-off-by: Markus Schneider-Pargmann Reviewed-by: Simon Horman Link: https://lore.kernel.org/all/20240207093220.2681425-9-msp@baylibre.com Signed-off-by: Marc Kleine-Budde