Re: Linux 6.19-rc1 mediatek mt7921e broke badly

["Thomas Weißschuh" <linux@weissschuh.net>]

On 2025-12-30 16:57:20-0700, Shuah Khan wrote:
> On 12/29/25 21:21, Matthew Schwartz wrote:
> > On 12/29/25 4:41 PM, Linus Torvalds wrote:
> > > On Sat, 27 Dec 2025 at 04:25, Thomas Weißschuh <linux@weissschuh.net> wrote:
> > > > 
> > > > Hi Shuah,
> > > > 
> > > > On 2025-12-27 02:07:24-0700, Shuah Khan wrote:
> > > > > mt7921e doesn't load on my primary laptopn on Linux 6.19-rc1 and problem
> > > > > still there on 6.19-rc2.
> > > > 
> > > > This should be a duplicate of
> > > > https://lore.kernel.org/all/CABXGCsMeAZyNJ-Axt_CUCXgyieWPV3rrcLpWsveMPT8R0YPGnQ@mail.gmail.com/

(...)
 
> Reverting the following fixed my problem.
> f804a5895eba ("wifi: mt76: Strip whitespace from build ddate")
> 
> The above fixes an extra newline in the dmesg by making the
> code more complex it needs to introducing local buffers and
> strscpy() - the proposed fix replaces this with memcpy().
> 
> Is there a simple way to do this than introducing memcpy()
> or strscpy() to remove an extra newline that might or might
> not exist? Why not check if newline exists or not using
> strstr()?

We do have memtostr() which would be a perfect fit to use here.
That is still a memcpy() under the hood, but the code is clear and safe.
It does however require the source to be annotated as __nonstring.
Which also seems to be the right choice here anyways. However for
consistency, all other similar fields should also be annotated in the
same way. So it is a bit of a larger change than a pure bugfix.


Thomas