[PATCH 00/34] address all -Wunused-const warnings

[PATCH 00/34] address all -Wunused-const warnings

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

Compilers traditionally warn for unused 'static' variables, but not
if they are constant. The reason here is a custom for C++ programmers
to define named constants as 'static const' variables in header files
instead of using macros or enums.

In W=1 builds, we get warnings only static const variables in C
files, but not in headers, which is a good compromise, but this still
produces warning output in at least 30 files. These warnings are
almost all harmless, but also trivial to fix, and there is no
good reason to warn only about the non-const variables being unused.

I've gone through all the files that I found using randconfig and
allmodconfig builds and created patches to avoid these warnings,
with the goal of retaining a clean build once the option is enabled
by default.

Unfortunately, there is one fairly large patch ("drivers: remove
incorrect of_match_ptr/ACPI_PTR annotations") that touches
34 individual drivers that all need the same one-line change.
If necessary, I can split it up by driver or by subsystem,
but at least for reviewing I would keep it as one piece for
the moment.

Please merge the individual patches through subsystem trees.
I expect that some of these will have to go through multiple
revisions before they are picked up, so anything that gets
applied early saves me from resending.

        Arnd

Arnd Bergmann (31):
  powerpc/fsl-soc: hide unused const variable
  ubsan: fix unused variable warning in test module
  platform: goldfish: remove ACPI_PTR() annotations
  i2c: pxa: hide unused icr_bits[] variable
  3c515: remove unused 'mtu' variable
  tracing: hide unused ftrace_event_id_fops
  Input: synaptics: hide unused smbus_pnp_ids[] array
  power: rt9455: hide unused rt9455_boost_voltage_values
  efi: sysfb: don't build when EFI is disabled
  clk: ti: dpll: fix incorrect #ifdef checks
  apm-emulation: hide an unused variable
  sisfb: hide unused variables
  dma/congiguous: avoid warning about unused size_bytes
  leds: apu: remove duplicate DMI lookup data
  iio: ad5755: hook up of_device_id lookup to platform driver
  greybus: arche-ctrl: move device table to its right location
  lib: checksum: hide unused expected_csum_ipv6_magic[]
  sunrpc: suppress warnings for unused procfs functions
  comedi: ni_atmio: avoid warning for unused device_ids[] table
  iwlegacy: don't warn for unused variables with DEBUG_FS=n
  drm/komeda: don't warn for unused debugfs files
  firmware: qcom_scm: mark qcom_scm_qseecom_allowlist as __maybe_unused
  crypto: ccp - drop platform ifdef checks
  usb: gadget: omap_udc: remove unused variable
  isdn: kcapi: don't build unused procfs code
  cpufreq: intel_pstate: hide unused intel_pstate_cpu_oob_ids[]
  net: xgbe: remove extraneous #ifdef checks
  Input: imagis - remove incorrect ifdef checks
  sata: mv: drop unnecessary #ifdef checks
  ASoC: remove incorrect of_match_ptr/ACPI_PTR annotations
  spi: remove incorrect of_match_ptr annotations
  drivers: remove incorrect of_match_ptr/ACPI_PTR annotations
  kbuild: always enable -Wunused-const-variable

Krzysztof Kozlowski (1):
  Input: stmpe-ts - mark OF related data as maybe unused

 arch/powerpc/sysdev/fsl_msi.c                 |  2 +
 drivers/ata/sata_mv.c                         | 64 +++++++++----------
 drivers/char/apm-emulation.c                  |  5 +-
 drivers/char/ipmi/ipmb_dev_int.c              |  2 +-
 drivers/char/tpm/tpm_ftpm_tee.c               |  2 +-
 drivers/clk/ti/dpll.c                         | 10 ++-
 drivers/comedi/drivers/ni_atmio.c             |  2 +-
 drivers/cpufreq/intel_pstate.c                |  2 +
 drivers/crypto/ccp/sp-platform.c              | 14 +---
 drivers/dma/img-mdc-dma.c                     |  2 +-
 drivers/firmware/efi/Makefile                 |  3 +-
 drivers/firmware/efi/sysfb_efi.c              |  2 -
 drivers/firmware/qcom/qcom_scm.c              |  2 +-
 drivers/fpga/versal-fpga.c                    |  2 +-
 .../gpu/drm/arm/display/komeda/komeda_dev.c   |  8 ---
 drivers/hid/hid-google-hammer.c               |  6 +-
 drivers/i2c/busses/i2c-pxa.c                  |  2 +-
 drivers/i2c/muxes/i2c-mux-ltc4306.c           |  2 +-
 drivers/i2c/muxes/i2c-mux-reg.c               |  2 +-
 drivers/iio/dac/ad5755.c                      |  1 +
 drivers/input/mouse/synaptics.c               |  2 +
 drivers/input/touchscreen/imagis.c            |  4 +-
 drivers/input/touchscreen/stmpe-ts.c          |  2 +-
 drivers/input/touchscreen/wdt87xx_i2c.c       |  2 +-
 drivers/isdn/capi/Makefile                    |  3 +-
 drivers/isdn/capi/kcapi.c                     |  7 +-
 drivers/leds/leds-apu.c                       |  3 +-
 drivers/mux/adg792a.c                         |  2 +-
 drivers/net/ethernet/3com/3c515.c             |  3 -
 drivers/net/ethernet/amd/xgbe/xgbe-platform.c |  8 ---
 drivers/net/ethernet/apm/xgene-v2/main.c      |  2 +-
 drivers/net/ethernet/hisilicon/hns_mdio.c     |  2 +-
 drivers/net/wireless/intel/iwlegacy/4965-rs.c | 15 +----
 drivers/net/wireless/intel/iwlegacy/common.h  |  2 -
 drivers/platform/goldfish/goldfish_pipe.c     |  2 +-
 drivers/power/supply/rt9455_charger.c         |  2 +
 drivers/regulator/pbias-regulator.c           |  2 +-
 drivers/regulator/twl-regulator.c             |  2 +-
 drivers/regulator/twl6030-regulator.c         |  2 +-
 drivers/rtc/rtc-fsl-ftm-alarm.c               |  2 +-
 drivers/scsi/hisi_sas/hisi_sas_v1_hw.c        |  2 +-
 drivers/scsi/hisi_sas/hisi_sas_v2_hw.c        |  2 +-
 drivers/spi/spi-armada-3700.c                 |  2 +-
 drivers/spi/spi-img-spfi.c                    |  2 +-
 drivers/spi/spi-meson-spicc.c                 |  2 +-
 drivers/spi/spi-meson-spifc.c                 |  2 +-
 drivers/spi/spi-orion.c                       |  2 +-
 drivers/spi/spi-pic32-sqi.c                   |  2 +-
 drivers/spi/spi-pic32.c                       |  2 +-
 drivers/spi/spi-rockchip.c                    |  2 +-
 drivers/spi/spi-s3c64xx.c                     |  2 +-
 drivers/spi/spi-st-ssc4.c                     |  2 +-
 drivers/staging/greybus/arche-apb-ctrl.c      |  1 +
 drivers/staging/greybus/arche-platform.c      |  9 +--
 drivers/staging/pi433/pi433_if.c              |  2 +-
 drivers/tty/serial/amba-pl011.c               |  6 +-
 drivers/tty/serial/ma35d1_serial.c            |  2 +-
 drivers/usb/gadget/udc/omap_udc.c             | 10 +--
 drivers/video/fbdev/sis/init301.c             |  3 +-
 kernel/dma/contiguous.c                       |  2 +-
 kernel/trace/trace_events.c                   |  4 ++
 lib/checksum_kunit.c                          |  2 +
 lib/test_ubsan.c                              |  2 +-
 net/sunrpc/cache.c                            | 10 +--
 scripts/Makefile.extrawarn                    |  1 -
 sound/soc/atmel/sam9x5_wm8731.c               |  2 +-
 sound/soc/codecs/rt5514-spi.c                 |  2 +-
 sound/soc/qcom/lpass-sc7280.c                 |  2 +-
 sound/soc/samsung/aries_wm8994.c              |  2 +-
 69 files changed, 121 insertions(+), 169 deletions(-)

-- 
2.39.2

Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Corey Minyard <minyard@acm.org>
Cc: Peter Huewe <peterhuewe@gmx.de>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Tero Kristo <kristo@kernel.org>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Ian Abbott <abbotti@mev.co.uk>
Cc: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: John Allen <john.allen@amd.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Bjorn Andersson <andersson@kernel.org>
Cc: Moritz Fischer <mdf@kernel.org>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: Andi Shyti <andi.shyti@kernel.org>
Cc: Michael Hennerich <michael.hennerich@analog.com>
Cc: Peter Rosin <peda@axentia.se>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Markuss Broks <markuss.broks@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: Lee Jones <lee@kernel.org>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Cc: Iyappan Subramanian <iyappan@os.amperecomputing.com>
Cc: Yisen Zhuang <yisen.zhuang@huawei.com>
Cc: Stanislaw Gruszka <stf_xl@wp.pl>
Cc: Kalle Valo <kvalo@kernel.org>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Xiang Chen <chenxiang66@hisilicon.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Neil Armstrong <neil.armstrong@linaro.org>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Vaibhav Hiremath <hvaibhav.linux@gmail.com>
Cc: Alex Elder <elder@kernel.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Jacky Huang <ychuang3@nuvoton.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-ide@vger.kernel.org
Cc: openipmi-developer@lists.sourceforge.net
Cc: linux-integrity@vger.kernel.org
Cc: linux-omap@vger.kernel.org
Cc: linux-clk@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: linux-crypto@vger.kernel.org
Cc: dmaengine@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Cc: linux-arm-msm@vger.kernel.org
Cc: linux-fpga@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-input@vger.kernel.org
Cc: linux-i2c@vger.kernel.org
Cc: linux-iio@vger.kernel.org
Cc: linux-stm32@st-md-mailman.stormreply.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: netdev@vger.kernel.org
Cc: linux-leds@vger.kernel.org
Cc: linux-wireless@vger.kernel.org
Cc: linux-rtc@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: linux-spi@vger.kernel.org
Cc: linux-amlogic@lists.infradead.org
Cc: linux-rockchip@lists.infradead.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: greybus-dev@lists.linaro.org
Cc: linux-staging@lists.linux.dev
Cc: linux-serial@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Cc: linux-fbdev@vger.kernel.org
Cc: iommu@lists.linux.dev
Cc: linux-trace-kernel@vger.kernel.org
Cc: kasan-dev@googlegroups.com
Cc: linux-hardening@vger.kernel.org
Cc: linux-nfs@vger.kernel.org
Cc: linux-kbuild@vger.kernel.org
Cc: alsa-devel@alsa-project.org
Cc: linux-sound@vger.kernel.org

[PATCH 14/34] dma/congiguous: avoid warning about unused size_bytes

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

When building with W=1, this variable is unused for configs with
CONFIG_CMA_SIZE_SEL_PERCENTAGE=y:

kernel/dma/contiguous.c:67:26: error: 'size_bytes' defined but not used [-Werror=unused-const-variable=]

Mark it as __maybe_unused to avoid the warning without adding more
ifdef checks to this file.

Fixes: c64be2bb1c6e ("drivers: add Contiguous Memory Allocator")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 kernel/dma/contiguous.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
index 055da410ac71..c53f4f633f7f 100644
--- a/kernel/dma/contiguous.c
+++ b/kernel/dma/contiguous.c
@@ -64,7 +64,7 @@ struct cma *dma_contiguous_default_area;
  * Users, who want to set the size of global CMA area for their system
  * should use cma= kernel parameter.
  */
-static const phys_addr_t size_bytes __initconst =
+static const phys_addr_t size_bytes __initconst __maybe_unused =
 	(phys_addr_t)CMA_SIZE_MBYTES * SZ_1M;
 static phys_addr_t  size_cmdline __initdata = -1;
 static phys_addr_t base_cmdline __initdata;
-- 
2.39.2

Re: [PATCH 14/34] dma/congiguous: avoid warning about unused size_bytes

[Christoph Hellwig]

contiguous is misspelled in the subject.

Instead of the __maybe_unused annotation I'd just conver it to a
cpp #define.  I can take care of that if you want.

Re: [PATCH 00/34] address all -Wunused-const warnings

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Wed,  3 Apr 2024 10:06:18 +0200 you wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> Compilers traditionally warn for unused 'static' variables, but not
> if they are constant. The reason here is a custom for C++ programmers
> to define named constants as 'static const' variables in header files
> instead of using macros or enums.
> 
> [...]

Here is the summary with links:
  - [05/34] 3c515: remove unused 'mtu' variable
    https://git.kernel.org/netdev/net-next/c/17b35355c2c6
  - [19/34] sunrpc: suppress warnings for unused procfs functions
    (no matching commit)
  - [26/34] isdn: kcapi: don't build unused procfs code
    https://git.kernel.org/netdev/net-next/c/91188544af06
  - [28/34] net: xgbe: remove extraneous #ifdef checks
    https://git.kernel.org/netdev/net-next/c/0ef416e045ad
  - [33/34] drivers: remove incorrect of_match_ptr/ACPI_PTR annotations
    (no matching commit)

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

Re: (subset) [PATCH 00/34] address all -Wunused-const warnings

[Sebastian Reichel]

On Wed, 03 Apr 2024 10:06:18 +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> Compilers traditionally warn for unused 'static' variables, but not
> if they are constant. The reason here is a custom for C++ programmers
> to define named constants as 'static const' variables in header files
> instead of using macros or enums.
> 
> [...]

Applied, thanks!

[09/34] power: rt9455: hide unused rt9455_boost_voltage_values
        commit: 452d8950db3e839aba1bb13bc5378f4bac11fa04

Best regards,
-- 
Sebastian Reichel <sebastian.reichel@collabora.com>

Re: (subset) [PATCH 00/34] address all -Wunused-const warnings

[Michael Ellerman]

On Wed, 03 Apr 2024 10:06:18 +0200, Arnd Bergmann wrote:
> Compilers traditionally warn for unused 'static' variables, but not
> if they are constant. The reason here is a custom for C++ programmers
> to define named constants as 'static const' variables in header files
> instead of using macros or enums.
> 
> In W=1 builds, we get warnings only static const variables in C
> files, but not in headers, which is a good compromise, but this still
> produces warning output in at least 30 files. These warnings are
> almost all harmless, but also trivial to fix, and there is no
> good reason to warn only about the non-const variables being unused.
> 
> [...]

Applied to powerpc/next.

[01/34] powerpc/fsl-soc: hide unused const variable
        https://git.kernel.org/powerpc/c/01acaf3aa75e1641442cc23d8fe0a7bb4226efb1

cheers

Re: [PATCH 00/34] address all -Wunused-const warnings

[Andy Shevchenko]

On Wed, Apr 03, 2024 at 10:06:18AM +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> Compilers traditionally warn for unused 'static' variables, but not
> if they are constant. The reason here is a custom for C++ programmers
> to define named constants as 'static const' variables in header files
> instead of using macros or enums.
> 
> In W=1 builds, we get warnings only static const variables in C
> files, but not in headers, which is a good compromise, but this still
> produces warning output in at least 30 files. These warnings are
> almost all harmless, but also trivial to fix, and there is no
> good reason to warn only about the non-const variables being unused.
> 
> I've gone through all the files that I found using randconfig and
> allmodconfig builds and created patches to avoid these warnings,
> with the goal of retaining a clean build once the option is enabled
> by default.
> 
> Unfortunately, there is one fairly large patch ("drivers: remove
> incorrect of_match_ptr/ACPI_PTR annotations") that touches
> 34 individual drivers that all need the same one-line change.
> If necessary, I can split it up by driver or by subsystem,
> but at least for reviewing I would keep it as one piece for
> the moment.
> 
> Please merge the individual patches through subsystem trees.
> I expect that some of these will have to go through multiple
> revisions before they are picked up, so anything that gets
> applied early saves me from resending.

Arnd, can you refresh this one? It seems some misses still...
I have got 3+ 0-day reports against one of the mux drivers.

https://lore.kernel.org/all/?q=adg792a.c

-- 
With Best Regards,
Andy Shevchenko