Re: [PATCH] ch_ktls: fix build warning for ipv4-only config

[Jakub Kicinski]

On Thu,  3 Dec 2020 23:26:16 +0100 Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
> 
> When CONFIG_IPV6 is disabled, clang complains that a variable
> is uninitialized for non-IPv4 data:
> 
> drivers/net/ethernet/chelsio/inline_crypto/ch_ktls/chcr_ktls.c:1046:6: error: variable 'cntrl1' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
>         if (tx_info->ip_family == AF_INET) {
>             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/net/ethernet/chelsio/inline_crypto/ch_ktls/chcr_ktls.c:1059:2: note: uninitialized use occurs here
>         cntrl1 |= T6_TXPKT_ETHHDR_LEN_V(maclen - ETH_HLEN) |
>         ^~~~~~
> 
> Replace the preprocessor conditional with the corresponding C version,
> and make the ipv4 case unconditional in this configuration to improve
> readability and avoid the warning.
> 
> Fixes: 86716b51d14f ("ch_ktls: Update cheksum information")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

This is for evrey clang build or just W=1+? Would be annoying if clang
produced this on every build with 5.10 (we need to decide fix vs -next).