Subject: Re: [PATCH 1/2] net: thunderbolt: Fix sparse warnings

From: Andy Shevchenko <[email-masked]>
Date: Wed, 5 Apr 2023 11:45:43 +0300

On Tue, Apr 04, 2023 at 08:36:35AM +0300, Mika Westerberg wrote:
> Fixes the following warnings when the driver is built with sparse
> checks enabled:

> drivers/net/thunderbolt/main.c:767:47: warning: restricted __le32 degrades to integer
> drivers/net/thunderbolt/main.c:775:47: warning: restricted __le16 degrades to integer
> drivers/net/thunderbolt/main.c:776:44: warning: restricted __le16 degrades to integer
> drivers/net/thunderbolt/main.c:876:40: warning: incorrect type in assignment (different base types)
> drivers/net/thunderbolt/main.c:876:40:    expected restricted __le32 [usertype] frame_size
> drivers/net/thunderbolt/main.c:876:40:    got unsigned int [assigned] [usertype] frame_size
> drivers/net/thunderbolt/main.c:877:41: warning: incorrect type in assignment (different base types)
> drivers/net/thunderbolt/main.c:877:41:    expected restricted __le32 [usertype] frame_count
> drivers/net/thunderbolt/main.c:877:41:    got unsigned int [usertype]
> drivers/net/thunderbolt/main.c:878:41: warning: incorrect type in assignment (different base types)
> drivers/net/thunderbolt/main.c:878:41:    expected restricted __le16 [usertype] frame_index
> drivers/net/thunderbolt/main.c:878:41:    got unsigned short [usertype]
> drivers/net/thunderbolt/main.c:879:38: warning: incorrect type in assignment (different base types)
> drivers/net/thunderbolt/main.c:879:38:    expected restricted __le16 [usertype] frame_id
> drivers/net/thunderbolt/main.c:879:38:    got unsigned short [usertype]
> drivers/net/thunderbolt/main.c:880:62: warning: restricted __le32 degrades to integer
> drivers/net/thunderbolt/main.c:880:35: warning: restricted __le16 degrades to integer
> drivers/net/thunderbolt/main.c:993:23: warning: incorrect type in initializer (different base types)
> drivers/net/thunderbolt/main.c:993:23:    expected restricted __wsum [usertype] wsum
> drivers/net/thunderbolt/main.c:993:23:    got restricted __be32 [usertype]

You can drop the whole part with file name and line numbers to make the above
neater.

> No functional changes intended.
> 
> Signed-off-by: Mika Westerberg <[email-masked]>
> ---
>  drivers/net/thunderbolt/main.c | 21 ++++++++++++---------
>  1 file changed, 12 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/net/thunderbolt/main.c b/drivers/net/thunderbolt/main.c
> index 26ef3706445e..6a43ced74881 100644
> --- a/drivers/net/thunderbolt/main.c
> +++ b/drivers/net/thunderbolt/main.c
> @@ -764,7 +764,7 @@ static bool tbnet_check_frame(struct tbnet *net, const struct tbnet_frame *tf,
>  	 */
>  	if (net->skb && net->rx_hdr.frame_count) {
>  		/* Check the frame count fits the count field */
> -		if (frame_count != net->rx_hdr.frame_count) {
> +		if (frame_count != le32_to_cpu(net->rx_hdr.frame_count)) {
>  			net->stats.rx_length_errors++;
>  			return false;
>  		}
> @@ -772,8 +772,8 @@ static bool tbnet_check_frame(struct tbnet *net, const struct tbnet_frame *tf,
>  		/* Check the frame identifiers are incremented correctly,
>  		 * and id is matching.
>  		 */
> -		if (frame_index != net->rx_hdr.frame_index + 1 ||
> -		    frame_id != net->rx_hdr.frame_id) {
> +		if (frame_index != le16_to_cpu(net->rx_hdr.frame_index) + 1 ||
> +		    frame_id != le16_to_cpu(net->rx_hdr.frame_id)) {
>  			net->stats.rx_missed_errors++;
>  			return false;
>  		}
> @@ -873,11 +873,12 @@ static int tbnet_poll(struct napi_struct *napi, int budget)
>  					TBNET_RX_PAGE_SIZE - hdr_size);
>  		}
>  
> -		net->rx_hdr.frame_size = frame_size;
> -		net->rx_hdr.frame_count = le32_to_cpu(hdr->frame_count);
> -		net->rx_hdr.frame_index = le16_to_cpu(hdr->frame_index);
> -		net->rx_hdr.frame_id = le16_to_cpu(hdr->frame_id);
> -		last = net->rx_hdr.frame_index == net->rx_hdr.frame_count - 1;
> +		net->rx_hdr.frame_size = hdr->frame_size;
> +		net->rx_hdr.frame_count = hdr->frame_count;
> +		net->rx_hdr.frame_index = hdr->frame_index;
> +		net->rx_hdr.frame_id = hdr->frame_id;
> +		last = le16_to_cpu(net->rx_hdr.frame_index) ==
> +		       le32_to_cpu(net->rx_hdr.frame_count) - 1;
>  
>  		rx_packets++;
>  		net->stats.rx_bytes += frame_size;
> @@ -990,8 +991,10 @@ static bool tbnet_xmit_csum_and_map(struct tbnet *net, struct sk_buff *skb,
>  {
>  	struct thunderbolt_ip_frame_header *hdr = page_address(frames[0]->page);
>  	struct device *dma_dev = tb_ring_dma_device(net->tx_ring.ring);
> -	__wsum wsum = htonl(skb->len - skb_transport_offset(skb));
>  	unsigned int i, len, offset = skb_transport_offset(skb);
> +	/* Remove payload length from checksum */
> +	u32 paylen = skb->len - skb_transport_offset(skb);
> +	__wsum wsum = (__force __wsum)htonl(paylen);
>  	__be16 protocol = skb->protocol;
>  	void *data = skb->data;
>  	void *dest = hdr + 1;

I would split wsum fix from the above as they are of different nature.

-- 
With Best Regards,
Andy Shevchenko