[PATCH v3 7/7] of: Add KUnit test to confirm DTB is loaded

[Stephen Boyd]

Quoting David Gow (2024-02-02 20:10:17)
> On Sat, 3 Feb 2024 at 03:59, Stephen Boyd <sboyd at kernel.org> wrote:
> >
> > Add a KUnit test that confirms a DTB has been loaded, i.e. there is a
> > root node, and that the of_have_populated_dt() API works properly.
> >
> > Cc: Rob Herring <robh+dt at kernel.org>
> > Cc: Frank Rowand <frowand.list at gmail.com>
> > Cc: David Gow <davidgow at google.com>
> > Cc: Brendan Higgins <brendan.higgins at linux.dev>
> > Signed-off-by: Stephen Boyd <sboyd at kernel.org>
> > ---
> 
> This looks pretty good to me test-wise, though it still fails on m68k.
> (Everything else I tried it on works, though I've definitely not tried
> _every_ architecture.)
> 
> aarch64: PASSED
> i386: PASSED
> x86_64: PASSED
> x86_64 KASAN: PASSED
> powerpc64: PASSED
> UML: PASSED
> UML LLVM: PASSED
> m68k: FAILED
> > $ qemu-system-m68k -nodefaults -m 1024 -kernel .kunit-all-m68k/vmlinux -append 'kunit.enable=1 console=hvc0 kunit_shutdown=reboot' -no-reboot -nographic -serial stdio -machine virt
> > [11:55:05] ===================== dtb (2 subtests) =====================
> > [11:55:05] # dtb_root_node_found_by_path: EXPECTATION FAILED at drivers/of/of_test.c:18
> > [11:55:05] Expected np is not null, but is
> > [11:55:05] [FAILED] dtb_root_node_found_by_path
> > [11:55:05] # dtb_root_node_populates_of_root: EXPECTATION FAILED at drivers/of/of_test.c:28
> > [11:55:05] Expected of_root is not null, but is
> > [11:55:05] [FAILED] dtb_root_node_populates_of_root
> > [11:55:05]     # module: of_test
> > [11:55:05] # dtb: pass:0 fail:2 skip:0 total:2
> > [11:55:05] # Totals: pass:0 fail:2 skip:0 total:2
> > [11:55:05] ======================= [FAILED] dtb =======================

Ah yeah I forgot to mention that. m68k fails because it doesn't call the
unflatten_(and_copy)?_device_tree() function, so we don't populate a
root node on that architecture. One solution would be to make CONFIG_OF
unavailable on m68k. Or we have to make sure DT works on any
architecture. Rob, what do you prefer here?

> 
> 
> My only other question is about the test names: the mix of 'of' and
> 'dtb' can be a bit confusing. As is, we have:
> kconfig name: OF_KUNIT_TEST
> module name: of_test
> suite name: dtb
> test names: all start with dtb_
> 
> Given KUnit only really deals with the suite/test names directly, it's
> not trivial to see that 'dtb.dtb_*' is controlled by OF_KUNIT_TEST and
> in of_test if built as a module. (This is getting a bit easier now
> that we have the 'module' attribute in the output, but still.)
> 
> Would 'of_dtb' work as a suite name if it's important to keep both
> 'of' and 'dtb'?

Sure, I can add of_ prefix to the tests.

> 
> In general, though, this test looks good to me. Particularly if m68k
> can be fixed.
> 
> Reviewed-by: David Gow <davidgow at google.com>
> 

Thanks!