diff options
| author | Marc Kleine-Budde <mkl@pengutronix.de> | 2020-12-21 23:48:20 +0300 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2021-01-27 12:01:47 +0300 |
| commit | 561aa5b4ce223064ea655da899013bec5326ec45 (patch) | |
| tree | ad80e6ddd71acc83a74893686f35a8fd34121da8 /drivers/net/can/spi/mcp251xfd | |
| parent | 9845b8f530196fd86fcc46c1c1298bf94b1604bf (diff) | |
| download | linux-561aa5b4ce223064ea655da899013bec5326ec45.tar.xz | |
can: mcp251xfd: mcp251xfd_tx_obj_from_skb(): clean up padding of CAN-FD frames
CAN-FD frames have only specific frame length (0, 1, 2, 3, 4, 5, 6, 7, 8, 12,
16, 20, 24, 32, 48, 64). A CAN-FD frame provided by user space might not cover
the whole CAN-FD frame. To avoid sending garbage over the CAN bus the driver
pads the CAN frame with 0x0 (if MCP251XFD_SANITIZE_CAN is activated).
This patch cleans up the pad len calculation. Rounding to full u32 brings no
benefit, in case of CRC transfers, the hw_tx_obj->data is not aligned to u32
anyway.
Link: https://lore.kernel.org/r/20210114153448.1506901-3-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers/net/can/spi/mcp251xfd')
| -rw-r--r-- | drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c index 1dbb87c28049..aa992e71d787 100644 --- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c +++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c @@ -2303,7 +2303,7 @@ mcp251xfd_tx_obj_from_skb(const struct mcp251xfd_priv *priv, union mcp251xfd_tx_obj_load_buf *load_buf; u8 dlc; u32 id, flags; - int offset, len; + int pad_len, len; if (cfd->can_id & CAN_EFF_FLAG) { u32 sid, eid; @@ -2351,13 +2351,14 @@ mcp251xfd_tx_obj_from_skb(const struct mcp251xfd_priv *priv, put_unaligned_le32(id, &hw_tx_obj->id); put_unaligned_le32(flags, &hw_tx_obj->flags); - /* Clear data at end of CAN frame */ - offset = round_down(cfd->len, sizeof(u32)); - len = round_up(can_fd_dlc2len(dlc), sizeof(u32)) - offset; - if (MCP251XFD_SANITIZE_CAN && len) - memset(hw_tx_obj->data + offset, 0x0, len); + /* Copy data */ memcpy(hw_tx_obj->data, cfd->data, cfd->len); + /* Clear unused data at end of CAN frame */ + pad_len = can_fd_dlc2len(dlc) - cfd->len; + if (MCP251XFD_SANITIZE_CAN && pad_len) + memset(hw_tx_obj->data + cfd->len, 0x0, pad_len); + /* Number of bytes to be written into the RAM of the controller */ len = sizeof(hw_tx_obj->id) + sizeof(hw_tx_obj->flags); if (MCP251XFD_SANITIZE_CAN) |