On Sun, 9 Nov 2025, Stephen Rothwell wrote:
> On Sun, 9 Nov 2025 09:49:29 +0900 Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote:
> > On Sun, Nov 09, 2025 at 10:52:03AM +1100, Stephen Rothwell wrote:
> > > On Fri, 7 Nov 2025 07:20:26 +0100 Jiri Slaby <jirislaby@kernel.org> wrote:  
> > > >
> > > > On 06. 11. 25, 19:00, Ilpo Järvinen wrote:  
> > > > > This seems to resolve the build issue for me:
> > > > > 
> > > > > --
> > > > > From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= <ilpo.jarvinen@linux.intel.com>
> > > > > Subject: [PATCH 1/1] serial: 8250: Fix 8250_rsa symbol loop
> > > > > 
> > > > > make allmodconfig build fails due to dependency loop:
> > > > > 
> > > > >    depmod: ERROR: Cycle detected: 8250 -> 8250_base -> 8250
> > > > >    depmod: ERROR: Found 2 modules in dependency cycles!
> > > > > 
> > > > > Break dependency loop by moving 8250_rsa.o into 8250_base and by
> > > > > passing univ8250_port_base_ops to univ8250_rsa_support() that can make
> > > > > a local copy of it.
> > > > > 
> > > > > Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
> > > > > Reported-by: Alex Davis <alex47794@gmail.com>
> > > > > Fixes: b20d6576cdb3 ("serial: 8250: export RSA functions")
> > > > > Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>    
> > > > 
> > > > LGTM, thanks for the fix.
> > > > 
> > > > Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
> > > > 
> > > > If the reporters could give it a shot and mark this by Tested-by, it would be great...  
> > > 
> > > I have not seen this for quite some time ... I assumed it had been
> > > fixed.  
> > 
> > I too thought this was fixed a while ago, what changed to cause this to
> > happen now?  Anyone have a .config to reproduce this, 'allmodconfig' on
> > x86 works for me.
> 
> Actually, I think the current report is for v6.17.1-rc1, so maybe
> something got missed in a stable backport? My original report was for
> next-20250728 (July 28).  The only response I got was on October 1,
> but I am pretty sure it was fixed well before then.
> 
> Also, you probably only get the error when you do a "make
> modules_install" after the allmodconfig build (at least that is where I
> got it).

Hi all,

I don't want to waste my time building allmodconfig but this is with 
allnoconfig + a few key CONFIGs set and without my patch:

$ git log -n1
commit e9a6fb0bcdd7609be6969112f3fbfcce3b1d4a7c (grafted, HEAD -> master, 
tag: v6.18-rc5, origin/master, origin/HEAD)
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Sun Nov 9 15:10:19 2025 -0800

    Linux 6.18-rc5
$ make allnoconfig
  LEX     scripts/kconfig/lexer.lex.c
  YACC    scripts/kconfig/parser.tab.[ch]
  HOSTCC  scripts/kconfig/lexer.lex.o
  HOSTCC  scripts/kconfig/menu.o
  HOSTCC  scripts/kconfig/parser.tab.o
  HOSTCC  scripts/kconfig/preprocess.o
  HOSTCC  scripts/kconfig/symbol.o
  HOSTCC  scripts/kconfig/util.o
  HOSTLD  scripts/kconfig/conf
#
# configuration written to .config
#
$ echo -e "CONFIG_MODULES=y\nCONFIG_SERIAL_8250=m\nCONFIG_SERIAL_8250_EXTENDED=y\nCONFIG_SERIAL_8250_RSA=y" >> .config 
$ make olddefconfig
.config:1528:warning: override: reassigning to symbol MODULES
.config:1529:warning: override: reassigning to symbol SERIAL_8250
.config:1530:warning: override: reassigning to symbol SERIAL_8250_EXTENDED
#
# configuration written to .config
#
$ make -j4 > /dev/null && sudo make modules_install
  INSTALL /lib/modules/6.18.0-rc5/modules.order
  INSTALL /lib/modules/6.18.0-rc5/modules.builtin
  INSTALL /lib/modules/6.18.0-rc5/modules.builtin.modinfo
  SYMLINK /lib/modules/6.18.0-rc5/build
  INSTALL /lib/modules/6.18.0-rc5/kernel/drivers/tty/serial/8250/8250.ko
  INSTALL /lib/modules/6.18.0-rc5/kernel/drivers/tty/serial/8250/8250_base.ko
  INSTALL /lib/modules/6.18.0-rc5/kernel/drivers/tty/serial/serial_base.ko
  DEPMOD  /lib/modules/6.18.0-rc5
depmod: ERROR: Cycle detected: 8250 -> 8250_base -> 8250
depmod: ERROR: Found 2 modules in dependency cycles!
make[2]: *** [scripts/Makefile.modinst:132: depmod] Error 1
make[1]: *** [/home/user/linux/Makefile:1916: modules_install] Error 2
make: *** [Makefile:248: __sub-make] Error 2

...so no, it does not look fixed.

With the patch:

$ git am 0001-serial-8250-Fix-8250_rsa-symbol-loop.patch 
Applying: serial: 8250: Fix 8250_rsa symbol loop
user@disp1097:~/linux$ make -j4 > /dev/null && sudo make modules_install
  SYMLINK /lib/modules/6.18.0-rc5+/build
  INSTALL /lib/modules/6.18.0-rc5+/modules.order
  INSTALL /lib/modules/6.18.0-rc5+/modules.builtin
  INSTALL /lib/modules/6.18.0-rc5+/modules.builtin.modinfo
  INSTALL /lib/modules/6.18.0-rc5+/kernel/drivers/tty/serial/8250/8250.ko
  INSTALL /lib/modules/6.18.0-rc5+/kernel/drivers/tty/serial/8250/8250_base.ko
  INSTALL /lib/modules/6.18.0-rc5+/kernel/drivers/tty/serial/serial_base.ko
  DEPMOD  /lib/modules/6.18.0-rc5+
$ 

I'll just make the official submission with the #else block's prototype 
fixed (thanks to lkp).

-- 
 i.