This is a note to let you know that I've just added the patch titled can: kvaser_pciefd: Empty SRB buffer in probe to the 6.3-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-kvaser_pciefd-empty-srb-buffer-in-probe.patch and it can be found in the queue-6.3 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From c589557dd1426f5adf90c7a919d4fde5a3e4ef64 Mon Sep 17 00:00:00 2001 From: Jimmy Assarsson <extja@xxxxxxxxxx> Date: Tue, 16 May 2023 15:43:16 +0200 Subject: can: kvaser_pciefd: Empty SRB buffer in probe From: Jimmy Assarsson <extja@xxxxxxxxxx> commit c589557dd1426f5adf90c7a919d4fde5a3e4ef64 upstream. Empty the "Shared receive buffer" (SRB) in probe, to assure we start in a known state, and don't process any irrelevant packets. Fixes: 26ad340e582d ("can: kvaser_pciefd: Add driver for Kvaser PCIEcan devices") Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Jimmy Assarsson <extja@xxxxxxxxxx> Link: https://lore.kernel.org/r/20230516134318.104279-5-extja@xxxxxxxxxx Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/can/kvaser_pciefd.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) --- a/drivers/net/can/kvaser_pciefd.c +++ b/drivers/net/can/kvaser_pciefd.c @@ -71,10 +71,12 @@ MODULE_DESCRIPTION("CAN driver for Kvase #define KVASER_PCIEFD_SYSID_BUILD_REG (KVASER_PCIEFD_SYSID_BASE + 0x14) /* Shared receive buffer registers */ #define KVASER_PCIEFD_SRB_BASE 0x1f200 +#define KVASER_PCIEFD_SRB_FIFO_LAST_REG (KVASER_PCIEFD_SRB_BASE + 0x1f4) #define KVASER_PCIEFD_SRB_CMD_REG (KVASER_PCIEFD_SRB_BASE + 0x200) #define KVASER_PCIEFD_SRB_IEN_REG (KVASER_PCIEFD_SRB_BASE + 0x204) #define KVASER_PCIEFD_SRB_IRQ_REG (KVASER_PCIEFD_SRB_BASE + 0x20c) #define KVASER_PCIEFD_SRB_STAT_REG (KVASER_PCIEFD_SRB_BASE + 0x210) +#define KVASER_PCIEFD_SRB_RX_NR_PACKETS_REG (KVASER_PCIEFD_SRB_BASE + 0x214) #define KVASER_PCIEFD_SRB_CTRL_REG (KVASER_PCIEFD_SRB_BASE + 0x218) /* EPCS flash controller registers */ #define KVASER_PCIEFD_SPI_BASE 0x1fc00 @@ -111,6 +113,9 @@ MODULE_DESCRIPTION("CAN driver for Kvase /* DMA support */ #define KVASER_PCIEFD_SRB_STAT_DMA BIT(24) +/* SRB current packet level */ +#define KVASER_PCIEFD_SRB_RX_NR_PACKETS_MASK 0xff + /* DMA Enable */ #define KVASER_PCIEFD_SRB_CTRL_DMA_ENABLE BIT(0) @@ -1059,6 +1064,7 @@ static int kvaser_pciefd_setup_dma(struc { int i; u32 srb_status; + u32 srb_packet_count; dma_addr_t dma_addr[KVASER_PCIEFD_DMA_COUNT]; /* Disable the DMA */ @@ -1086,6 +1092,15 @@ static int kvaser_pciefd_setup_dma(struc KVASER_PCIEFD_SRB_CMD_RDB1, pcie->reg_base + KVASER_PCIEFD_SRB_CMD_REG); + /* Empty Rx FIFO */ + srb_packet_count = ioread32(pcie->reg_base + KVASER_PCIEFD_SRB_RX_NR_PACKETS_REG) & + KVASER_PCIEFD_SRB_RX_NR_PACKETS_MASK; + while (srb_packet_count) { + /* Drop current packet in FIFO */ + ioread32(pcie->reg_base + KVASER_PCIEFD_SRB_FIFO_LAST_REG); + srb_packet_count--; + } + srb_status = ioread32(pcie->reg_base + KVASER_PCIEFD_SRB_STAT_REG); if (!(srb_status & KVASER_PCIEFD_SRB_STAT_DI)) { dev_err(&pcie->pci->dev, "DMA not idle before enabling\n"); Patches currently in stable-queue which might be from extja@xxxxxxxxxx are queue-6.3/can-kvaser_pciefd-call-request_irq-before-enabling-interrupts.patch queue-6.3/can-kvaser_pciefd-set-can_state_stopped-in-kvaser_pciefd_stop.patch queue-6.3/can-kvaser_pciefd-clear-listen-only-bit-if-not-explicitly-requested.patch queue-6.3/can-kvaser_pciefd-empty-srb-buffer-in-probe.patch queue-6.3/can-kvaser_pciefd-disable-interrupts-in-probe-error-path.patch queue-6.3/can-kvaser_pciefd-do-not-send-eflush-command-on-tfd-interrupt.patch