Re: [PATCH] mcb: Fix incorrect sanity check

From: Johannes Thumshirn

Date: Fri Nov 21 2025 - 05:54:11 EST


On 11/21/25 11:33 AM, Jose Javier Rodriguez Barbarin wrote:
On Thu, Nov 20, 2025 at 12:48:45PM +0100, Johannes Thumshirn wrote:
On 11/20/25 12:37 PM, Jose Javier Rodriguez Barbarin wrote:
__mcb_register_driver() makes some sanity checks over mcb_driver
to check if .probe and .remove callbacks are set. However, not all
mcb device drivers implement .remove callback.

Remove .remove check to ensure all mcb device drivers can be loaded.
The only driver I can see that doesn't implement a .remove method is
gpio-menz127.c.
Yes. In the past gpio-menz127.c also implemented .remove method, however in

3bd13ae04ccc ("gpio: menz127: simplify error path and remove remove()")

The driver changed, using now devm_* functions so .remove was no longer necessary.

Is this safe?

From the point of view of mcb bus it should be safe becase I protected the call
of .remove on mcb_remove(), preventing possible crashes when the driver is removed
from the bus.

I'm afraid I'm lossing something because I cannot understand why these changes are or
not safe. Could you explain me why you understand that these changes are unsafe?


Thanks this is the information I was missing from the changelog. I'll change the commit message to:

__mcb_register_driver() makes some sanity checks over mcb_driver
to check if .probe and .remove callbacks are set. However, since commit
3bd13ae04ccc ("gpio: menz127: simplify error path and remove remove()")
removed the .remove callback from menz127-gpio.c, not all mcb device
drivers implement .remove callback.

Remove .remove check to ensure all mcb device drivers can be loaded.

I'll also add

Fixes: 3bd13ae04ccc ("gpio: menz127: simplify error path and remove remove()")


Thanks,

    Johannes