Re: build failure of next-20220818 due to 341dd1f7de4c ("wifi: rtw88: add the update channel flow to support setting by parameters")

[Ping-Ke Shih <pkshih@realtek.com>]

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@gmail.com> 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@realtek.com/T/#u

Ping-Ke