On Thu, 2022-08-18 at 13:56 +0200, Arnd Bergmann wrote:
> On Thu, Aug 18, 2022 at 1:40 PM Sudip Mukherjee (Codethink)
> <sudipm.mukherjee@xxxxxxxxx> wrote:
> > Hi All,
> >
> > Not sure if it has been reported, clang builds of arm64 allmodconfig have
> > failed to build next-20220818 with the error:
> >
> > drivers/net/wireless/realtek/rtw88/main.c:731:2: error: variable 'primary_channel_idx' is used
> > uninitialized whenever switch default is taken [-Werror,-Wsometimes-uninitialized]
> > default:
> > ^~~~~~~
> > drivers/net/wireless/realtek/rtw88/main.c:754:39: note: uninitialized use occurs here
> > hal->current_primary_channel_index = primary_channel_idx;
> > ^~~~~~~~~~~~~~~~~~~
> >
> > git bisect pointed to 341dd1f7de4c ("wifi: rtw88: add the update channel flow to support setting
> > by parameters").
> > And, reverting that commit has fixed the build failure.
> >
> > I will be happy to test any patch or provide any extra log if needed.
>
> Hi Sudeep,
>
> in my experience, you get the best results by posting a patch instead
> of a bug report
> when you spot a new warning. If you are unsure it's the right fix,
> just state that
> in the description. The maintainers will then either be able to just
> pick it up if
> it looks correct, or be motivated to do a better patch if they don't
> like it. ;-)
>
> In this case, I think the best fix would be to merged the 'default'
> with the 'case
> RTW_CHANNEL_WIDTH_20' in the switch statement, and use
> RTW_SC_DONT_CARE. Of course, I have no idea if that is the right fix,
> but it would make sense.
>
> Just try to avoid adding initializations to the variable declaration, as that
> would prevent the compiler from warning if there is a new uninitialized use.
>
I have sent a patch to fix this:
https://lore.kernel.org/linux-wireless/20220815062004.22920-1-pkshih@xxxxxxxxxxx/T/#u
Ping-Ke
