Replace all hardcoded values supplied to the len element of esd_usb_msg (and its siblings) by more readable expressions, based on sizeof(), offsetof(), etc. Also spend documentation / comments that the len element of esd_usb_msg is in multiples of 32bit words and not in bytes. Link: https://lore.kernel.org/all/CAMZ6RqLaDNy-fZ2G0+QMhUEckkXLL+ZyELVSDFmqpd++aBzZQg@xxxxxxxxxxxxxx/ Suggested-by: Vincent MAILHOL <mailhol.vincent@xxxxxxxxxx> Signed-off-by: Frank Jungclaus <frank.jungclaus@xxxxxx> --- drivers/net/can/usb/esd_usb.c | 40 ++++++++++++++++++----------------- 1 file changed, 21 insertions(+), 19 deletions(-) diff --git a/drivers/net/can/usb/esd_usb.c b/drivers/net/can/usb/esd_usb.c index 24eebb7ee5f1..a6a3ecb6eac6 100644 --- a/drivers/net/can/usb/esd_usb.c +++ b/drivers/net/can/usb/esd_usb.c @@ -90,13 +90,13 @@ MODULE_LICENSE("GPL v2"); #define ESD_USB_MAX_TX_URBS 16 /* must be power of 2 */ struct esd_usb_header_msg { - u8 len; /* len is always the total message length in 32bit words */ + u8 len; /* total message length in 32bit words */ u8 cmd; u8 rsvd[2]; }; struct esd_usb_version_msg { - u8 len; + u8 len; /* total message length in 32bit words */ u8 cmd; u8 rsvd; u8 flags; @@ -104,7 +104,7 @@ struct esd_usb_version_msg { }; struct esd_usb_version_reply_msg { - u8 len; + u8 len; /* total message length in 32bit words */ u8 cmd; u8 nets; u8 features; @@ -115,7 +115,7 @@ struct esd_usb_version_reply_msg { }; struct esd_usb_rx_msg { - u8 len; + u8 len; /* total message length in 32bit words */ u8 cmd; u8 net; u8 dlc; @@ -133,7 +133,7 @@ struct esd_usb_rx_msg { }; struct esd_usb_tx_msg { - u8 len; + u8 len; /* total message length in 32bit words */ u8 cmd; u8 net; u8 dlc; @@ -143,7 +143,7 @@ struct esd_usb_tx_msg { }; struct esd_usb_tx_done_msg { - u8 len; + u8 len; /* total message length in 32bit words */ u8 cmd; u8 net; u8 status; @@ -152,15 +152,15 @@ struct esd_usb_tx_done_msg { }; struct esd_usb_id_filter_msg { - u8 len; + u8 len; /* total message length in 32bit words */ u8 cmd; u8 net; u8 option; - __le32 mask[ESD_USB_MAX_ID_SEGMENT + 1]; + __le32 mask[ESD_USB_MAX_ID_SEGMENT + 1]; /* +1 for 29bit extended IDs */ }; struct esd_usb_set_baudrate_msg { - u8 len; + u8 len; /* total message length in 32bit words */ u8 cmd; u8 net; u8 rsvd; @@ -438,7 +438,7 @@ static void esd_usb_read_bulk_callback(struct urb *urb) break; } - pos += msg->hdr.len << 2; + pos += msg->hdr.len * sizeof(u32); /* convert to # of bytes */ if (pos > urb->actual_length) { dev_err(dev->udev->dev.parent, "format error\n"); @@ -532,7 +532,7 @@ static int esd_usb_send_msg(struct esd_usb *dev, union esd_usb_msg *msg) return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2), msg, - msg->hdr.len << 2, + msg->hdr.len * sizeof(u32), /* convert to # of bytes */ &actual_length, 1000); } @@ -648,7 +648,7 @@ static int esd_usb_start(struct esd_usb_net_priv *priv) * field followed by only some bitmasks. */ msg->hdr.cmd = ESD_USB_CMD_IDADD; - msg->hdr.len = 2 + ESD_USB_MAX_ID_SEGMENT; + msg->hdr.len = sizeof(struct esd_usb_id_filter_msg) / sizeof(u32); /* # of 32bit words */ msg->filter.net = priv->index; msg->filter.option = ESD_USB_ID_ENABLE; /* start with segment 0 */ for (i = 0; i < ESD_USB_MAX_ID_SEGMENT; i++) @@ -759,7 +759,8 @@ static netdev_tx_t esd_usb_start_xmit(struct sk_buff *skb, msg = (union esd_usb_msg *)buf; - msg->hdr.len = 3; /* minimal length */ + /* minimal length as # of 32bit words */ + msg->hdr.len = offsetof(struct esd_usb_tx_msg, data) / sizeof(u32); msg->hdr.cmd = ESD_USB_CMD_CAN_TX; msg->tx.net = priv->index; msg->tx.dlc = can_get_cc_dlc(cf, priv->can.ctrlmode); @@ -774,7 +775,8 @@ static netdev_tx_t esd_usb_start_xmit(struct sk_buff *skb, for (i = 0; i < cf->len; i++) msg->tx.data[i] = cf->data[i]; - msg->hdr.len += (cf->len + 3) >> 2; + /* round up, then divide by 4 to add the payload length as # of 32bit words */ + msg->hdr.len += DIV_ROUND_UP(cf->len, sizeof(u32)); for (i = 0; i < ESD_USB_MAX_TX_URBS; i++) { if (priv->tx_contexts[i].echo_index == ESD_USB_MAX_TX_URBS) { @@ -797,7 +799,7 @@ static netdev_tx_t esd_usb_start_xmit(struct sk_buff *skb, msg->tx.hnd = 0x80000000 | i; /* returned in TX done message */ usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf, - msg->hdr.len << 2, + msg->hdr.len * sizeof(u32), /* convert to # of bytes */ esd_usb_write_bulk_callback, context); urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; @@ -860,7 +862,7 @@ static int esd_usb_close(struct net_device *netdev) /* Disable all IDs (see esd_usb_start()) */ msg->hdr.cmd = ESD_USB_CMD_IDADD; - msg->hdr.len = 2 + ESD_USB_MAX_ID_SEGMENT; + msg->hdr.len = sizeof(struct esd_usb_id_filter_msg) / sizeof(u32);/* # of 32bit words */ msg->filter.net = priv->index; msg->filter.option = ESD_USB_ID_ENABLE; /* start with segment 0 */ for (i = 0; i <= ESD_USB_MAX_ID_SEGMENT; i++) @@ -869,7 +871,7 @@ static int esd_usb_close(struct net_device *netdev) netdev_err(netdev, "sending idadd message failed\n"); /* set CAN controller to reset mode */ - msg->hdr.len = 2; + msg->hdr.len = sizeof(struct esd_usb_set_baudrate_msg) / sizeof(u32); /* # of 32bit words */ msg->hdr.cmd = ESD_USB_CMD_SETBAUD; msg->setbaud.net = priv->index; msg->setbaud.rsvd = 0; @@ -947,7 +949,7 @@ static int esd_usb_2_set_bittiming(struct net_device *netdev) if (!msg) return -ENOMEM; - msg->hdr.len = 2; + msg->hdr.len = sizeof(struct esd_usb_set_baudrate_msg) / sizeof(u32); /* # of 32bit words */ msg->hdr.cmd = ESD_USB_CMD_SETBAUD; msg->setbaud.net = priv->index; msg->setbaud.rsvd = 0; @@ -1086,7 +1088,7 @@ static int esd_usb_probe(struct usb_interface *intf, /* query number of CAN interfaces (nets) */ msg->hdr.cmd = ESD_USB_CMD_VERSION; - msg->hdr.len = 2; + msg->hdr.len = sizeof(struct esd_usb_version_msg) / sizeof(u32); /* # of 32bit words */ msg->version.rsvd = 0; msg->version.flags = 0; msg->version.drv_version = 0; -- 2.25.1
