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Commit e5ac4f12 authored by Jimmy Assarsson's avatar Jimmy Assarsson Committed by Greg Kroah-Hartman
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can: kvaser_pciefd: Empty SRB buffer in probe 



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: 26ad340e ("can: kvaser_pciefd: Add driver for Kvaser PCIEcan devices")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarJimmy Assarsson <extja@kvaser.com>
Link: https://lore.kernel.org/r/20230516134318.104279-5-extja@kvaser.com


Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent c0e9fb21

drivers/net/can/kvaser_pciefd.c

+15 −0
Original line number Diff line number Diff line
@@ -70,10 +70,12 @@ MODULE_DESCRIPTION("CAN driver for Kvaser CAN/PCIe devices"); 
#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
@@ -110,6 +112,9 @@ MODULE_DESCRIPTION("CAN driver for Kvaser CAN/PCIe devices"); 
/* 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)
@@ -1053,6 +1058,7 @@ static int kvaser_pciefd_setup_dma(struct kvaser_pciefd *pcie) 
{

	int i;

	u32 srb_status;

	u32 srb_packet_count;

	dma_addr_t dma_addr[KVASER_PCIEFD_DMA_COUNT];



	/* Disable the DMA */
@@ -1080,6 +1086,15 @@ static int kvaser_pciefd_setup_dma(struct kvaser_pciefd *pcie) 
		  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");