Arnd Bergmann <arnd@xxxxxxxxxx> wrote:
> Including an aligned structure inside of a packed one is ambiguous
> and can lead to misaligned data, as pointed out by this clang warning:
>
> drivers/net/wireless/ath/ath10k/htt.h:715:34: error: field prefix within 'struct htt_rx_indication' is less aligned than 'struct htt_rx_indication_prefix' and is usually due to 'struct htt_rx_indication' being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access]
> struct htt_rx_indication_prefix prefix;
> ^
> drivers/net/wireless/ath/ath10k/htt.h:736:34: error: field prefix within 'struct htt_rx_indication_hl' is less aligned than 'struct htt_rx_indication_prefix' and is usually due to 'struct htt_rx_indication_hl' being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access]
> struct htt_rx_indication_prefix prefix;
> ^
> drivers/net/wireless/ath/ath10k/htt.h:1564:2: error: field within 'struct htt_tx_fetch_ind' is less aligned than 'union htt_tx_fetch_ind::(anonymous at drivers/net/wireless/ath/ath10k/htt.h:1564:2)' and is usually due to 'struct htt_tx_fetch_ind' being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access]
> union {
> ^
> drivers/net/wireless/ath/ath10k/htt.h:1702:2: error: field within 'struct htt_resp' is less aligned than 'union htt_resp::(anonymous at drivers/net/wireless/ath/ath10k/htt.h:1702:2)' and is usually due to 'struct htt_resp' being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access]
>
> These structures appear to actually need the packing since they
> are embedded at misaligned offsets. Add even more such annotations
> here to enforce bytewise access throughout the driver.
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> Signed-off-by: Kalle Valo <quic_kvalo@xxxxxxxxxxx>
Patch applied to ath-next branch of ath.git, thanks.
12ec37be3faf wifi: ath10k: improve structure padding
--
https://patchwork.kernel.org/project/linux-wireless/patch/20230616090439.2484857-1-arnd@xxxxxxxxxx/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
