Re: linux-next: build failure after merge of the driver-core tree

From: Jeffrey Hugo
Date: Tue Apr 11 2023 - 11:09:28 EST


On 4/11/2023 9:01 AM, Daniel Vetter wrote:
On Tue, Apr 11, 2023 at 12:40:28PM +0200, Greg KH wrote:
On Tue, Apr 11, 2023 at 11:55:20AM +0200, Daniel Vetter wrote:
On Tue, Apr 11, 2023 at 02:38:12PM +1000, Stephen Rothwell wrote:
Hi all,

After merging the driver-core tree, today's linux-next build (x86_64
allmodconfig) failed like this:

In file included from include/linux/linkage.h:7,
from include/linux/kernel.h:17,
from drivers/accel/qaic/mhi_qaic_ctrl.c:4:
drivers/accel/qaic/mhi_qaic_ctrl.c: In function 'mhi_qaic_ctrl_init':
include/linux/export.h:27:22: error: passing argument 1 of 'class_create' from incompatible pointer type [-Werror=incompatible-pointer-types]
27 | #define THIS_MODULE (&__this_module)
| ~^~~~~~~~~~~~~~~
| |
| struct module *
drivers/accel/qaic/mhi_qaic_ctrl.c:544:38: note: in expansion of macro 'THIS_MODULE'
544 | mqc_dev_class = class_create(THIS_MODULE, MHI_QAIC_CTRL_DRIVER_NAME);
| ^~~~~~~~~~~
In file included from include/linux/device.h:31,
from include/linux/mhi.h:9,
from drivers/accel/qaic/mhi_qaic_ctrl.c:5:
include/linux/device/class.h:229:54: note: expected 'const char *' but argument is of type 'struct module *'
229 | struct class * __must_check class_create(const char *name);
| ~~~~~~~~~~~~^~~~
drivers/accel/qaic/mhi_qaic_ctrl.c:544:25: error: too many arguments to function 'class_create'
544 | mqc_dev_class = class_create(THIS_MODULE, MHI_QAIC_CTRL_DRIVER_NAME);
| ^~~~~~~~~~~~
include/linux/device/class.h:229:29: note: declared here
229 | struct class * __must_check class_create(const char *name);
| ^~~~~~~~~~~~

Caused by commit

1aaba11da9aa ("driver core: class: remove module * from class_create()")

interacting with commit

566fc96198b4 ("accel/qaic: Add mhi_qaic_cntl")

from the drm tree.

I have applied the following merge fix patch for today.

From: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Date: Tue, 11 Apr 2023 14:16:57 +1000
Subject: [PATCH] fixup for "driver core: class: remove module * from class_create()"

interacting with "accel/qaic: Add mhi_qaic_cntl"

Signed-off-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>

Thanks for the fixup. Since Dave is out I've made a note about this in my
handover mail so it won't get lost in the drm-next merge window pull. I
don't think we need any other coordination than mention it in each pull to
Linus, topic tree seems overkill for this. Plus there's no way I can
untangle the drm tree anyway :-).

Want me to submit a patch for the drm tree that moves this to use
class_register() instead, which will make the merge/build issue go away
for you? That's my long-term goal here anyway, so converting this new
code to this api today would be something I have to do eventually :)

We kinda closed drm-next for feature work mostly already (just pulling
stuff in from subtrees), so won't really help for this merge window.

For everything else I think this is up to Oded, I had no idea qaic needed
it's entire own dev class and I don't want to dig into this for the risk I
might freak out :-)

Adding Oded.

Cheers, Daniel

Sorry for the mess.

I made a note to update to class_register() once my drm-misc access is sorted out. Looks like we'll address the conflict in the merge window, and catch the update to the new API in the following release.

-Jeff