From: Marc Kleine-Budde <mkl@pengutronix.de>
To: netdev@vger.kernel.org
Cc: davem@davemloft.net, kuba@kernel.org, linux-can@vger.kernel.org,
kernel@pengutronix.de, Marc Kleine-Budde <mkl@pengutronix.de>
Subject: [net-next 08/12] can: mcp251xfd: mcp251xfd_tx_obj_from_skb(): clean up padding of CAN-FD frames
Date: Wed, 27 Jan 2021 10:22:23 +0100 [thread overview]
Message-ID: <20210127092227.2775573-9-mkl@pengutronix.de> (raw)
In-Reply-To: <20210127092227.2775573-1-mkl@pengutronix.de>
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>
---
drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c | 13 +++++++------
1 file 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)
--
2.29.2
next prev parent reply other threads:[~2021-01-27 9:30 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-27 9:22 pull-request: can-next 2021-01-27 Marc Kleine-Budde
2021-01-27 9:22 ` [net-next 01/12] can: gw: fix typo Marc Kleine-Budde
2021-01-28 3:10 ` patchwork-bot+netdevbpf
2021-01-27 9:22 ` [net-next 02/12] can: flexcan: fix typos Marc Kleine-Budde
2021-01-27 9:22 ` [net-next 03/12] can: dev: export can_get_state_str() function Marc Kleine-Budde
2021-01-27 9:22 ` [net-next 04/12] can: length: can_fd_len2dlc(): make legnth calculation readable again Marc Kleine-Budde
2021-01-27 9:22 ` [net-next 05/12] can: mcba_usb: remove h from printk format specifier Marc Kleine-Budde
2021-01-27 9:22 ` [net-next 06/12] can: mcp251xfd: replace sizeof(u32) with val_bytes in regmap Marc Kleine-Budde
2021-01-27 9:22 ` [net-next 07/12] can: mcp251xfd: mcp251xfd_start_xmit(): use mcp251xfd_get_tx_free() to check TX is is full Marc Kleine-Budde
2021-01-27 9:22 ` Marc Kleine-Budde [this message]
2021-01-27 9:22 ` [net-next 09/12] can: mcp251xfd: mcp251xfd_hw_rx_obj_to_skb(): don't copy data for RTR CAN frames in RX-path Marc Kleine-Budde
2021-01-27 9:22 ` [net-next 10/12] can: mcp251xfd: mcp251xfd_tx_obj_from_skb(): don't copy data for RTR CAN frames in TX-path Marc Kleine-Budde
2021-01-27 9:22 ` [net-next 11/12] can: mcp251xfd: add len8_dlc support Marc Kleine-Budde
2021-01-27 9:22 ` [net-next 12/12] can: mcp251xfd: add BQL support Marc Kleine-Budde
2021-01-28 3:10 ` pull-request: can-next 2021-01-27 patchwork-bot+netdevbpf
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