Commit a68eda20 authored by Marc Kleine-Budde's avatar Marc Kleine-Budde

can: mcp251xfd: mcp251xfd_tx_obj_from_skb(): don't copy data for RTR CAN frames in TX-path

In Classical CAN there are RTR frames. RTR frames have the RTR bit set, may
have a dlc != 0, but contain no data.

This patch optimizes the TX-path to not copy any data for RTR frames.

Link: https://lore.kernel.org/r/20210114153448.1506901-5-mkl@pengutronix.deSigned-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent e20b85c7
...@@ -2304,7 +2304,7 @@ mcp251xfd_tx_obj_from_skb(const struct mcp251xfd_priv *priv, ...@@ -2304,7 +2304,7 @@ mcp251xfd_tx_obj_from_skb(const struct mcp251xfd_priv *priv,
union mcp251xfd_tx_obj_load_buf *load_buf; union mcp251xfd_tx_obj_load_buf *load_buf;
u8 dlc; u8 dlc;
u32 id, flags; u32 id, flags;
int pad_len, len; int len_sanitized = 0, len;
if (cfd->can_id & CAN_EFF_FLAG) { if (cfd->can_id & CAN_EFF_FLAG) {
u32 sid, eid; u32 sid, eid;
...@@ -2331,6 +2331,8 @@ mcp251xfd_tx_obj_from_skb(const struct mcp251xfd_priv *priv, ...@@ -2331,6 +2331,8 @@ mcp251xfd_tx_obj_from_skb(const struct mcp251xfd_priv *priv,
if (cfd->can_id & CAN_RTR_FLAG) if (cfd->can_id & CAN_RTR_FLAG)
flags |= MCP251XFD_OBJ_FLAGS_RTR; flags |= MCP251XFD_OBJ_FLAGS_RTR;
else
len_sanitized = canfd_sanitize_len(cfd->len);
/* CANFD */ /* CANFD */
if (can_is_canfd_skb(skb)) { if (can_is_canfd_skb(skb)) {
...@@ -2356,14 +2358,18 @@ mcp251xfd_tx_obj_from_skb(const struct mcp251xfd_priv *priv, ...@@ -2356,14 +2358,18 @@ mcp251xfd_tx_obj_from_skb(const struct mcp251xfd_priv *priv,
memcpy(hw_tx_obj->data, cfd->data, cfd->len); memcpy(hw_tx_obj->data, cfd->data, cfd->len);
/* Clear unused data at end of CAN frame */ /* Clear unused data at end of CAN frame */
pad_len = can_fd_dlc2len(dlc) - cfd->len; if (MCP251XFD_SANITIZE_CAN && len_sanitized) {
if (MCP251XFD_SANITIZE_CAN && pad_len) int pad_len;
pad_len = len_sanitized - cfd->len;
if (pad_len)
memset(hw_tx_obj->data + cfd->len, 0x0, pad_len); memset(hw_tx_obj->data + cfd->len, 0x0, pad_len);
}
/* Number of bytes to be written into the RAM of the controller */ /* Number of bytes to be written into the RAM of the controller */
len = sizeof(hw_tx_obj->id) + sizeof(hw_tx_obj->flags); len = sizeof(hw_tx_obj->id) + sizeof(hw_tx_obj->flags);
if (MCP251XFD_SANITIZE_CAN) if (MCP251XFD_SANITIZE_CAN)
len += round_up(can_fd_dlc2len(dlc), sizeof(u32)); len += round_up(len_sanitized, sizeof(u32));
else else
len += round_up(cfd->len, sizeof(u32)); len += round_up(cfd->len, sizeof(u32));
......
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