Hi Kalle, On 2/16/19 5:21 AM, Kalle Valo wrote: > (replying to an old thread but renaming it) > > Kalle Valo <kvalo@xxxxxxxxxxxxxx> writes: > >> "Gustavo A. R. Silva" <gustavo@xxxxxxxxxxxxxx> wrote: >> >>> In preparation to enabling -Wimplicit-fallthrough, mark switch cases >>> where we are expecting to fall through. >>> >>> Notice that in this particular case, I replaced "pass through" with >>> a proper "fall through" comment, which is what GCC is expecting >>> to find. >>> >>> Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx> >>> Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx> >> >> Patch applied to ath-next branch of ath.git, thanks. >> >> f1d270ae10ff ath10k: htt_tx: mark expected switch fall-throughs > > Gustavo, I enabled W=1 on my ath10k build checks and it took me a while > to figure out why GCC was warning about fall through annotations missing > even I knew you had fixed them. Finally I figured out that the reason > was ccache, which I need because I work with different branches and need > to recompile the kernel quite often. > > If the plan is to enable -Wimplicit-fallthrough by default in the kernel > IMHO this might become an issue, as otherwise people using ccache start > seeing lots of invalid warnings. Apparently CCACHE_COMMENTS=1 will fix > that but my version of ccache doesn't support it, and how would everyone > learn that trick anyway? Or maybe CCACHE_COMMENTS can enabled through > kernel Makefile? > Can you share with me the warning messages you get? I just see the following warnings with linux-next: $ make CC="ccache gcc" W=1 drivers/net/wireless/ath/ath10k/htt_tx.o CC [M] drivers/net/wireless/ath/ath10k/htt_tx.o In file included from drivers/net/wireless/ath/ath10k/htt_tx.c:19: drivers/net/wireless/ath/ath10k/htt.h:1727:1: warning: alignment 1 of ‘struct ath10k_htt_txbuf_32’ is less than 4 [-Wpacked-not-aligned] } __packed; ^ drivers/net/wireless/ath/ath10k/htt.h:1734:1: warning: alignment 1 of ‘struct ath10k_htt_txbuf_64’ is less than 4 [-Wpacked-not-aligned] } __packed; ^ In my Makefile I have: KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough=3,) Thanks -- Gustavo
