Hi Dmitry,

On Sun, Jan 03, 2021 at 05:58:41PM -0800, Dmitry Torokhov wrote:

Hi Jeff,

On Sat, Dec 19, 2020 at 08:01:09PM -0600, Jeff LaBundy wrote:

quoted

Hi Dmitry,

On Fri, Dec 18, 2020 at 04:49:48PM +0000, Roy Im wrote:

quoted

On Friday, December 18, 2020 3:50 PM, Dmitry Torokhov wrote:

quoted

The OF match table is only used when OF is enabled.

Fixes: cd3f609823a5 ("Input: new da7280 haptic driver")
Reported-by: kernel test robot <redacted>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/input/misc/da7280.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/input/misc/da7280.c b/drivers/input/misc/da7280.c index 2f698a8c1d65..b08610d6e575 100644
--- a/drivers/input/misc/da7280.c
+++ b/drivers/input/misc/da7280.c

@@ -1300,11 +1300,13 @@ static int __maybe_unused da7280_resume(struct device *dev)
 	return retval;
 }

+#ifdef CONFIG_OF
 static const struct of_device_id da7280_of_match[] = {
 	{ .compatible = "dlg,da7280", },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, da7280_of_match);
+#endif

Just for my own understanding, would it not work just as well
to include of_device.h? This includes mod_devicetable.h which
in turn defines the of_device_id struct (even if CONFIG_OF is
not set).

The issue here is not that the structure is undefined, but the variable
is unused. We could also fix this by not using of_match_ptr() when
assigning the match table to the driver structure, making the variable
referenced even if CONFIG_OF is off.

ACK. The call to of_match_ptr() is what I was missing; the other
drivers I was looking at do not use it which must be why the bot
has not complained.

quoted

The reason for asking is because it seems many drivers do not
include these guards.

It could be that they are either only compiled with OF, or they decided
it is not worth saving a few bytes, or maybe they are used on ACPI-based
systems with PRP0001 bindings in which case the match table in the
driver might still be needed.

Makes perfect sense; thank you for the follow-up.

Thanks.

-- 
Dmitry

Kind regards,
Jeff LaBundy