Re: [PATCH 4/4] staging: r8188eu: use htons macro instead of __constant_htons

From: Joe Perches
Date: Wed Oct 19 2022 - 02:08:18 EST


On Mon, 2022-10-17 at 18:54 +0530, Deepak R Varma wrote:
> Macro "htons" is more efficiant and clearer. It should be used for
> constants instead of the __contast_htons macro. Resolves following

typo: __constant_htons

> checkpatch script complaint:
> WARNING: __constant_htons should be htons
[]
> diff --git a/drivers/staging/r8188eu/core/rtw_br_ext.c b/drivers/staging/r8188eu/core/rtw_br_ext.c
[]
> @@ -612,14 +612,14 @@ void dhcp_flag_bcast(struct adapter *priv, struct sk_buff *skb)
> if (!priv->ethBrExtInfo.dhcp_bcst_disable) {
> __be16 protocol = *((__be16 *)(skb->data + 2 * ETH_ALEN));
>
> - if (protocol == __constant_htons(ETH_P_IP)) { /* IP */
> + if (protocol == htons(ETH_P_IP)) { /* IP */
> struct iphdr *iph = (struct iphdr *)(skb->data + ETH_HLEN);
>
> if (iph->protocol == IPPROTO_UDP) { /* UDP */
> struct udphdr *udph = (struct udphdr *)((size_t)iph + (iph->ihl << 2));
>
> - if ((udph->source == __constant_htons(CLIENT_PORT)) &&
> - (udph->dest == __constant_htons(SERVER_PORT))) { /* DHCP request */
> + if ((udph->source == htons(CLIENT_PORT)) &&
> + (udph->dest == htons(SERVER_PORT))) { /* DHCP request */

OK, this bit seems fine

> struct dhcpMessage *dhcph =
> (struct dhcpMessage *)((size_t)udph + sizeof(struct udphdr));

IMO: this existing code however is ugly.
Casting a pointer to a size_t isn't great.

Perhaps:

struct dhcpMessage *dhcp;

dhcp = (void *)udhp + sizeof(struct udphdr);

in a separate patch.

> u32 cookie = be32_to_cpu((__be32)dhcph->cookie);

And dhcph->cookie already is a __be32 so the cast is pointless.

drivers/staging/r8188eu/core/rtw_br_ext.c-598- __be32 cookie;