On Fri, May 21, 2021 at 02:54:31PM +0300, Dan Carpenter wrote:

On Fri, May 21, 2021 at 08:26:35AM +0100, Lee Jones wrote:

quoted

On Thu, 20 May 2021, Ian Abbott wrote:

quoted

On 20/05/2021 13:25, Lee Jones wrote:

quoted

... and mark it as __maybe_unused since not all users of the
header file reference it.

Fixes the following W=1 kernel build warning(s):

  drivers/staging/comedi/drivers/ni_mio_common.c:163:35: warning: ‘range_ni_E_ao_ext’ defined but not used [-Wunused-const-variable=]

Cc: Ian Abbott <abbotti@mev.co.uk>
Cc: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Thierry Reding <redacted>
Cc: "Uwe Kleine-König" <redacted>
Cc: Lee Jones <redacted>
Cc: "David A. Schleef" <redacted>
Cc: Mori Hess <redacted>
Cc: Truxton Fulton <redacted>
Cc: linux-staging@lists.linux.dev
Cc: linux-pwm@vger.kernel.org
Signed-off-by: Lee Jones <redacted>
---
  drivers/comedi/drivers/ni_mio_common.c | 9 ---------
  drivers/comedi/drivers/ni_stc.h        | 9 ++++++++-
  2 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/drivers/comedi/drivers/ni_mio_common.c b/drivers/comedi/drivers/ni_mio_common.c
index 4f80a4991f953..37615b4e2c10d 100644
--- a/drivers/comedi/drivers/ni_mio_common.c
+++ b/drivers/comedi/drivers/ni_mio_common.c

@@ -160,15 +160,6 @@ static const struct comedi_lrange range_ni_M_ai_628x = {
  	}
  };
-static const struct comedi_lrange range_ni_E_ao_ext = {
-	4, {
-		BIP_RANGE(10),
-		UNI_RANGE(10),
-		RANGE_ext(-1, 1),
-		RANGE_ext(0, 1)
-	}
-};
-
  static const struct comedi_lrange *const ni_range_lkup[] = {
  	[ai_gain_16] = &range_ni_E_ai,
  	[ai_gain_8] = &range_ni_E_ai_limited,

diff --git a/drivers/comedi/drivers/ni_stc.h b/drivers/comedi/drivers/ni_stc.h
index fbc0b753a0f59..0822e65f709dd 100644
--- a/drivers/comedi/drivers/ni_stc.h
+++ b/drivers/comedi/drivers/ni_stc.h

@@ -1137,6 +1137,13 @@ struct ni_private {
  	u8 rgout0_usage;
  };
-static const struct comedi_lrange range_ni_E_ao_ext;
+static const struct comedi_lrange __maybe_unused range_ni_E_ao_ext = {
+	4, {
+		BIP_RANGE(10),
+		UNI_RANGE(10),
+		RANGE_ext(-1, 1),
+		RANGE_ext(0, 1)
+	}
+};
  #endif /* _COMEDI_NI_STC_H */

The "ni_stc.h" header is also included by "ni_mio_cs.c" which doesn't need
`range_ni_E_ao_ext` (admittedly, it was already pulling in a "tentative"
definition of the variable).

Thinking about it, I think it's probably better to move `range_ni_E_ao_ext`
from "ni_mio_common.c" into *both* "ni_atmio.c" and "ni_pcimio.c" (I think
we can live with the small amount of duplication), and to remove the
tentative definition from "ni_stc.h".

Happy to rework.

Am I taking this or Uwe's suggestion?

You should probably take Ian's suggestion because he is the maintainer
and I really doubt Uwe's will build.  :P  But Uwe is right that
including .c files is ugly.

I just tried

diff --git a/drivers/comedi/drivers/ni_mio_common.c b/drivers/comedi/drivers/ni_mio_common.c
index 4f80a4991f95..3b37c8b00ecd 100644
--- a/drivers/comedi/drivers/ni_mio_common.c
+++ b/drivers/comedi/drivers/ni_mio_common.c

@@ -160,7 +160,7 @@ static const struct comedi_lrange range_ni_M_ai_628x = {
 	}
 };
 
-static const struct comedi_lrange range_ni_E_ao_ext = {
+const struct comedi_lrange range_ni_E_ao_ext = {
 	4, {
 		BIP_RANGE(10),
 		UNI_RANGE(10),

diff --git a/drivers/comedi/drivers/ni_stc.h b/drivers/comedi/drivers/ni_stc.h
index fbc0b753a0f5..026d215f2ef2 100644
--- a/drivers/comedi/drivers/ni_stc.h
+++ b/drivers/comedi/drivers/ni_stc.h

@@ -1137,6 +1137,6 @@ struct ni_private {
 	u8 rgout0_usage;
 };
 
-static const struct comedi_lrange range_ni_E_ao_ext;
+extern const struct comedi_lrange range_ni_E_ao_ext;
 
 #endif /* _COMEDI_NI_STC_H */

and it built for me.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |