| Message ID | 20230802092647.3000666-1-sergio.paracuellos@gmail.com (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
| Series | clk: ralink: mtmips: quiet unused variable warning | expand |
On Wed, Aug 2, 2023 at 2:26 AM Sergio Paracuellos <sergio.paracuellos@gmail.com> wrote: > > When CONFIG_OF is disabled then the matching table is not referenced and > the following warning appears: > > drivers/clk/ralink/clk-mtmips.c:821:34: warning: unused variable 'mtmips_of_match' [-Wunused-const-variable] > 821 | static const struct of_device_id mtmips_of_match[] = { > | ^ > > Silence it declaring 'mtmips_of_match' with '__maybe_unused'. > > Fixes: 6f3b15586eef ("clk: ralink: add clock and reset driver for MTMIPS SoCs") > Reported-by: kernel test robot <lkp@intel.com> > Closes: https://lore.kernel.org/oe-kbuild-all/202307242310.CdOnd2py-lkp@intel.com/ > Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com> I think this is fine; Arnd or Nathan do you have a preference? or thoughts here? If not, thanks for the patch. Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> (I have a slight preference for wrapping the use in `#ifdef CONFIG_OF` since with the approach used by this patch, if all users are removed we will never get a warning for this var. But it's a weak preference; it's more important to me that we don't have -Werror promote this warning to a build breakage) > --- > drivers/clk/ralink/clk-mtmips.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/clk/ralink/clk-mtmips.c b/drivers/clk/ralink/clk-mtmips.c > index 1e7991439527..6716394b28a3 100644 > --- a/drivers/clk/ralink/clk-mtmips.c > +++ b/drivers/clk/ralink/clk-mtmips.c > @@ -820,7 +820,7 @@ static const struct mtmips_clk_data mt76x8_clk_data = { > .num_clk_periph = ARRAY_SIZE(mt76x8_pherip_clks), > }; > > -static const struct of_device_id mtmips_of_match[] = { > +static const __maybe_unused struct of_device_id mtmips_of_match[] = { > { > .compatible = "ralink,rt2880-sysc", > .data = &rt2880_clk_data, > -- > 2.25.1 >
On Wed, Aug 02, 2023 at 02:26:43PM -0700, Nick Desaulniers wrote: > On Wed, Aug 2, 2023 at 2:26 AM Sergio Paracuellos > <sergio.paracuellos@gmail.com> wrote: > > > > When CONFIG_OF is disabled then the matching table is not referenced and > > the following warning appears: > > > > drivers/clk/ralink/clk-mtmips.c:821:34: warning: unused variable 'mtmips_of_match' [-Wunused-const-variable] > > 821 | static const struct of_device_id mtmips_of_match[] = { > > | ^ > > > > Silence it declaring 'mtmips_of_match' with '__maybe_unused'. > > > > Fixes: 6f3b15586eef ("clk: ralink: add clock and reset driver for MTMIPS SoCs") > > Reported-by: kernel test robot <lkp@intel.com> > > Closes: https://lore.kernel.org/oe-kbuild-all/202307242310.CdOnd2py-lkp@intel.com/ > > Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com> > > I think this is fine; Arnd or Nathan do you have a preference? or thoughts here? I do not have much of a preference either, I tend to agree with your reasoning for preferring the #ifdef but '__maybe_unused' is relatively easy to audit on a per-file basis and I think that is more common than the '#ifdef CONFIG_OF'. Small nit, I think __maybe_unused typically goes between the variable name and equals, like static const struct of_device_id mtmips_of_match[] __maybe_unused = { but this is obviously fine. Regardless: Reviewed-by: Nathan Chancellor <nathan@kernel.org> > If not, thanks for the patch. > Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> > > (I have a slight preference for wrapping the use in `#ifdef CONFIG_OF` > since with the approach used by this patch, if all users are removed > we will never get a warning for this var. But it's a weak preference; > it's more important to me that we don't have -Werror promote this > warning to a build breakage) > > > --- > > drivers/clk/ralink/clk-mtmips.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/clk/ralink/clk-mtmips.c b/drivers/clk/ralink/clk-mtmips.c > > index 1e7991439527..6716394b28a3 100644 > > --- a/drivers/clk/ralink/clk-mtmips.c > > +++ b/drivers/clk/ralink/clk-mtmips.c > > @@ -820,7 +820,7 @@ static const struct mtmips_clk_data mt76x8_clk_data = { > > .num_clk_periph = ARRAY_SIZE(mt76x8_pherip_clks), > > }; > > > > -static const struct of_device_id mtmips_of_match[] = { > > +static const __maybe_unused struct of_device_id mtmips_of_match[] = { > > { > > .compatible = "ralink,rt2880-sysc", > > .data = &rt2880_clk_data, > > -- > > 2.25.1 > > > > > -- > Thanks, > ~Nick Desaulniers
On Wed, Aug 2, 2023, at 23:26, Nick Desaulniers wrote: > On Wed, Aug 2, 2023 at 2:26 AM Sergio Paracuellos <sergio.paracuellos@gmail.com> wrote: >> >> When CONFIG_OF is disabled then the matching table is not referenced and >> the following warning appears: >> >> drivers/clk/ralink/clk-mtmips.c:821:34: warning: unused variable 'mtmips_of_match' [-Wunused-const-variable] >> 821 | static const struct of_device_id mtmips_of_match[] = { >> | ^ >> >> Silence it declaring 'mtmips_of_match' with '__maybe_unused'. >> >> Fixes: 6f3b15586eef ("clk: ralink: add clock and reset driver for MTMIPS SoCs") >> Reported-by: kernel test robot <lkp@intel.com> >> Closes: https://lore.kernel.org/oe-kbuild-all/202307242310.CdOnd2py-lkp@intel.com/ >> Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com> > > I think this is fine; Arnd or Nathan do you have a preference? or thoughts here? > > If not, thanks for the patch. > Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> > > (I have a slight preference for wrapping the use in `#ifdef CONFIG_OF` > since with the approach used by this patch, if all users are removed > we will never get a warning for this var. But it's a weak preference; > it's more important to me that we don't have -Werror promote this > warning to a build breakage) I don't understand why there are two match tables in the same driver, with almost the same contents. I have not looked very closely here, but why can't we just drop the mtmips_clk_of_match[] table (the one without the .data fields) and use the same table for both? Is this because of the ralink,rt2880-reset entry that is missing in mtmips_of_match, or is that another bug? I also see that there is both a platform_driver instance for late probing and a list of CLK_OF_DECLARE_DRIVER() entries. Do we need both here? Arnd
On Thu, Aug 3, 2023, at 00:35, Sergio Paracuellos wrote: > Hi Arnd. > > El El jue, 3 ago 2023 a las 0:02, Arnd Bergmann <arnd@kernel.org> escribió: >> On Wed, Aug 2, 2023, at 23:26, Nick Desaulniers wrote: >> > On Wed, Aug 2, 2023 at 2:26 AM Sergio Paracuellos <sergio.paracuellos@gmail.com> wrote: >> >> >> >> When CONFIG_OF is disabled then the matching table is not referenced and >> >> the following warning appears: >> >> >> >> drivers/clk/ralink/clk-mtmips.c:821:34: warning: unused variable 'mtmips_of_match' [-Wunused-const-variable] >> >> 821 | static const struct of_device_id mtmips_of_match[] = { >> >> | ^ >> >> >> >> Silence it declaring 'mtmips_of_match' with '__maybe_unused'. >> >> >> >> Fixes: 6f3b15586eef ("clk: ralink: add clock and reset driver for MTMIPS SoCs") >> >> Reported-by: kernel test robot <lkp@intel.com> >> >> Closes: https://lore.kernel.org/oe-kbuild-all/202307242310.CdOnd2py-lkp@intel.com/ >> >> Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com> >> > >> > I think this is fine; Arnd or Nathan do you have a preference? or thoughts here? >> > >> > If not, thanks for the patch. >> > Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> >> > >> > (I have a slight preference for wrapping the use in `#ifdef CONFIG_OF` >> > since with the approach used by this patch, if all users are removed >> > we will never get a warning for this var. But it's a weak preference; >> > it's more important to me that we don't have -Werror promote this >> > warning to a build breakage) >> >> I don't understand why there are two match tables in the same >> driver, with almost the same contents. I have not looked very >> closely here, but why can't we just drop the mtmips_clk_of_match[] >> table (the one without the .data fields) and use the same >> table for both? Is this because of the ralink,rt2880-reset entry >> that is missing in mtmips_of_match, or is that another bug? > > ralink,rt2880-reset is for old dts compatibility and only applies to > reset driver. The one with data fields apply for clocks and is needed. Ok, I see. It still looks like the two tables can simply be merged by adding the ralink,rt2880-reset entry to mtmips_of_match[], which will allow it to be used for mtmips_clk_driver (which doesn't use the data) as well as for mtmips_clk_init() (which doesn't need get called for ralink,rt2880-reset). >> I also see that there is both a platform_driver instance for >> late probing and a list of CLK_OF_DECLARE_DRIVER() entries. >> Do we need both here? > > This system controller driver provide clock and reset controllers. > Clock cannot be a platform driver since we need to set > mips_hpr_frequency at a very early sargento. Reset stuff can be a > platform driver so both of them are needed. Arnd
Hi Arnd, Sorry for the late response. I was on a family vacation trip. On Thu, Aug 3, 2023 at 9:58 AM Arnd Bergmann <arnd@kernel.org> wrote: > > On Thu, Aug 3, 2023, at 00:35, Sergio Paracuellos wrote: > > Hi Arnd. > > > > El El jue, 3 ago 2023 a las 0:02, Arnd Bergmann <arnd@kernel.org> escribió: > >> On Wed, Aug 2, 2023, at 23:26, Nick Desaulniers wrote: > >> > On Wed, Aug 2, 2023 at 2:26 AM Sergio Paracuellos <sergio.paracuellos@gmail.com> wrote: > >> >> > >> >> When CONFIG_OF is disabled then the matching table is not referenced and > >> >> the following warning appears: > >> >> > >> >> drivers/clk/ralink/clk-mtmips.c:821:34: warning: unused variable 'mtmips_of_match' [-Wunused-const-variable] > >> >> 821 | static const struct of_device_id mtmips_of_match[] = { > >> >> | ^ > >> >> > >> >> Silence it declaring 'mtmips_of_match' with '__maybe_unused'. > >> >> > >> >> Fixes: 6f3b15586eef ("clk: ralink: add clock and reset driver for MTMIPS SoCs") > >> >> Reported-by: kernel test robot <lkp@intel.com> > >> >> Closes: https://lore.kernel.org/oe-kbuild-all/202307242310.CdOnd2py-lkp@intel.com/ > >> >> Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com> > >> > > >> > I think this is fine; Arnd or Nathan do you have a preference? or thoughts here? > >> > > >> > If not, thanks for the patch. > >> > Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> > >> > > >> > (I have a slight preference for wrapping the use in `#ifdef CONFIG_OF` > >> > since with the approach used by this patch, if all users are removed > >> > we will never get a warning for this var. But it's a weak preference; > >> > it's more important to me that we don't have -Werror promote this > >> > warning to a build breakage) > >> > >> I don't understand why there are two match tables in the same > >> driver, with almost the same contents. I have not looked very > >> closely here, but why can't we just drop the mtmips_clk_of_match[] > >> table (the one without the .data fields) and use the same > >> table for both? Is this because of the ralink,rt2880-reset entry > >> that is missing in mtmips_of_match, or is that another bug? > > > > ralink,rt2880-reset is for old dts compatibility and only applies to > > reset driver. The one with data fields apply for clocks and is needed. > > Ok, I see. It still looks like the two tables can simply be > merged by adding the ralink,rt2880-reset entry to mtmips_of_match[], > which will allow it to be used for mtmips_clk_driver (which doesn't > use the data) as well as for mtmips_clk_init() (which doesn't > need get called for ralink,rt2880-reset). I think I see your point, thank you. I'll do some test with this approach and will send a new patch properly addressing this. Thanks, Sergio Paracuellos > > >> I also see that there is both a platform_driver instance for > >> late probing and a list of CLK_OF_DECLARE_DRIVER() entries. > >> Do we need both here? > > > > This system controller driver provide clock and reset controllers. > > Clock cannot be a platform driver since we need to set > > mips_hpr_frequency at a very early sargento. Reset stuff can be a > > platform driver so both of them are needed. > > Arnd
diff --git a/drivers/clk/ralink/clk-mtmips.c b/drivers/clk/ralink/clk-mtmips.c index 1e7991439527..6716394b28a3 100644 --- a/drivers/clk/ralink/clk-mtmips.c +++ b/drivers/clk/ralink/clk-mtmips.c @@ -820,7 +820,7 @@ static const struct mtmips_clk_data mt76x8_clk_data = { .num_clk_periph = ARRAY_SIZE(mt76x8_pherip_clks), }; -static const struct of_device_id mtmips_of_match[] = { +static const __maybe_unused struct of_device_id mtmips_of_match[] = { { .compatible = "ralink,rt2880-sysc", .data = &rt2880_clk_data,
When CONFIG_OF is disabled then the matching table is not referenced and the following warning appears: drivers/clk/ralink/clk-mtmips.c:821:34: warning: unused variable 'mtmips_of_match' [-Wunused-const-variable] 821 | static const struct of_device_id mtmips_of_match[] = { | ^ Silence it declaring 'mtmips_of_match' with '__maybe_unused'. Fixes: 6f3b15586eef ("clk: ralink: add clock and reset driver for MTMIPS SoCs") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202307242310.CdOnd2py-lkp@intel.com/ Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com> --- drivers/clk/ralink/clk-mtmips.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)