kernel/linux.git/drivers/net/can/spi, branch linux-4.16.y

can: hi311x: Work around TX complete interrupt erratum

2018-05-16T08:12:31+00:00

commit 32bee8f48fa048a3198109de50e51c092507ff52 upstream. When sending packets as fast as possible using "cangen -g 0 -i -x", the HI-3110 occasionally latches the interrupt pin high on completion of a packet, but doesn't set the TXCPLT bit in the INTF register. The INTF register contains 0x00 as if no interrupt has occurred. Even waiting for a few milliseconds after the interrupt doesn't help. Work around this apparent erratum by instead checking the TXMTY bit in the STATF register ("TX FIFO empty"). We know that we've queued up a packet for transmission if priv->tx_len is nonzero. If the TX FIFO is empty, transmission of that packet must have completed. Note that this is congruent with our handling of received packets, which likewise gleans from the STATF register whether a packet is waiting in the RX FIFO, instead of looking at the INTF register. Cc: Mathias Duckeck Cc: Akshay Bhat Cc: Casey Fitzpatrick Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Lukas Wunner Acked-by: Akshay Bhat Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman

can: hi311x: Acquire SPI lock on ->do_get_berr_counter

2018-05-16T08:12:31+00:00

commit 5cec9425b41dcf834c3d48776900d6acb7e96f38 upstream. hi3110_get_berr_counter() may run concurrently to the rest of the driver but neglects to acquire the lock protecting access to the SPI device. As a result, it and the rest of the driver may clobber each other's tx and rx buffers. We became aware of this issue because transmission of packets with "cangen -g 0 -i -x" frequently hung. It turns out that agetty executes ->do_get_berr_counter every few seconds via the following call stack: CPU: 2 PID: 1605 Comm: agetty [<7f3f7500>] (hi3110_get_berr_counter [hi311x]) [<7f130204>] (can_fill_info [can_dev]) [<80693bc0>] (rtnl_fill_ifinfo) [<806949ec>] (rtnl_dump_ifinfo) [<806b4834>] (netlink_dump) [<806b4bc8>] (netlink_recvmsg) [<8065f180>] (sock_recvmsg) [<80660f90>] (___sys_recvmsg) [<80661e7c>] (__sys_recvmsg) [<80661ec0>] (SyS_recvmsg) [<80108b20>] (ret_fast_syscall+0x0/0x1c) agetty listens to netlink messages in order to update the login prompt when IP addresses change (if /etc/issue contains \4 or \6 escape codes): https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=e36deb6424e8 It's a useful feature, though it seems questionable that it causes CAN bit error statistics to be queried. Be that as it may, if hi3110_get_berr_counter() is invoked while a frame is sent by hi3110_hw_tx(), bogus SPI transfers like the following may occur: => 12 00 (hi3110_get_berr_counter() wanted to transmit EC 00 to query the transmit error counter, but the first byte was overwritten by hi3110_hw_tx_frame()) => EA 00 3E 80 01 FB (hi3110_hw_tx_frame() wanted to transmit a frame, but the first byte was overwritten by hi3110_get_berr_counter() because it wanted to query the receive error counter) This sequence hangs the transmission because the driver believes it has sent a frame and waits for the interrupt signaling completion, but in reality the chip has never sent away the frame since the commands it received were malformed. Fix by acquiring the SPI lock in hi3110_get_berr_counter(). I've scrutinized the entire driver for further unlocked SPI accesses but found no others. Cc: Mathias Duckeck Cc: Akshay Bhat Cc: Casey Fitzpatrick Cc: Stef Walter Cc: Karel Zak Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Lukas Wunner Reviewed-by: Akshay Bhat Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman

can: mcp251x: mcp251x_setup(): remove unused parameter "struct mcp251x_priv *priv"

2018-01-05T10:12:08+00:00

The 2nd parameter of mcp251x_setup() "struct mcp251x_priv *priv" is not used, so remove it. Suggested-by: Oleksij Rempel Signed-off-by: Marc Kleine-Budde

can: hi311x: Add Holt HI-311x CAN driver

2017-04-04T15:35:59+00:00

This patch adds support for the Holt HI-311x CAN controller. The HI311x CAN controller is capable of transmitting and receiving standard data frames, extended data frames and remote frames. The HI311x interfaces with the host over SPI. Datasheet: www.holtic.com/documents/371-hi-3110_v-rev-jpdf.do Signed-off-by: Akshay Bhat Acked-by: Wolfgang Grandegger Signed-off-by: Marc Kleine-Budde

can: mcp251x: add message about sucessful/unsuccessful probe

2016-06-23T09:23:49+00:00

Silent ignorance of errors during probe procedure is a bad thing, this patch fixes it. Extra message added for hardware initialization failure. Such common issues are mostly caused by wrong wiring. Message about success added as well, it should be useful to debug new hardware configuration, especially in case of several CAN buses. Signed-off-by: Ed Spiridonov Signed-off-by: Marc Kleine-Budde

can: mcp251x: Replace create_freezable_workqueue with alloc_workqueue

2016-05-09T09:07:28+00:00

Replace scheduled to be removed create_freezable_workqueue with alloc_workqueue. priv->wq should be explicitly set as freezable to ensure it is frozen in the suspend sequence and work items are drained so that no new work item starts execution until thawed. Thus, use of WQ_FREEZABLE flag here is required. WQ_MEM_RECLAIM flag has been set here to ensure forward progress regardless of memory pressure. The order of execution is not important so set @max_active as 0. Signed-off-by: Amitoj Kaur Chawla Acked-by: Tejun Heo Signed-off-by: Marc Kleine-Budde

can: mcp251x: avoid write to error flag register if it's unnecessary

2016-03-04T07:45:17+00:00

Only two bits (RX0OVR and RX1OVR) are writable in EFLG, write is useless if these bits aren't set. Signed-off-by: Ed Spiridonov Signed-off-by: Marc Kleine-Budde

spi: Drop owner assignment from spi_drivers

2015-10-28T01:30:17+00:00

An spi_driver does not need to set an owner, it will be populated by the driver core. Signed-off-by: Andrew F. Davis Acked-by: Jonathan Cameron Signed-off-by: Mark Brown

can: mcp251x: get regulators optionally

2015-07-16T07:04:22+00:00

The regulators power and transceiver are optional. If those are not present, the pointer (or error pointer) is correctly handled by the driver, hence we can use devm_regulator_get_optional safely, which avoids regulators getting created. Signed-off-by: Stefan Agner Signed-off-by: Marc Kleine-Budde

can: mcp251x: fix resume when device is down

2015-07-16T07:04:21+00:00

If a valid power regulator or a dummy regulator is used (which happens to be the case when no regulator is specified), restart_work is queued no matter whether the device was running or not at suspend time. Since work queues get initialized in the ndo_open callback, resuming leads to a NULL pointer exception. Reverse exactly the steps executed at suspend time: - Enable the power regulator in any case - Enable the transceiver regulator if the device was running, even in case we have a power regulator - Queue restart_work only in case the device was running Fixes: bf66f3736a94 ("can: mcp251x: Move to threaded interrupts instead of workqueues.") Signed-off-by: Stefan Agner Cc: linux-stable Signed-off-by: Marc Kleine-Budde