Re: [PATCH] serial: 8250: SERIAL_8250_FSL should not default to y when compile-testing
On Thu, Sep 16, 2021 at 10:55:49AM +0200, Geert Uytterhoeven wrote:
> Hi Johan,
>
> On Thu, Sep 16, 2021 at 10:46 AM Johan Hovold wrote:
> > On Wed, Sep 15, 2021 at 02:56:52PM +0200, Geert Uytterhoeven wrote:
> > > Commit b1442c55ce8977aa ("serial: 8250: extend compile-test coverage")
> > > added compile-test support to the Freescale 16550 driver. However, as
> > > SERIAL_8250_FSL is an invisible symbol, merely enabling COMPILE_TEST now
> > > enables this driver.
> > >
> > > Fix this by making SERIAL_8250_FSL visible. Tighten the dependencies to
> > > prevent asking the user about this driver when configuring a kernel
> > > without appropriate Freescale SoC or ACPI support.
> >
> > This tightening is arguable a separate change which risk introducing
> > regressions if you get it wrong and should go in a separate patch at
> > least.
>
> Getting it wrong would indeed be a regression, but not tightening
> that at the same time would mean I have to send a separate patch with
> a Fixes tag referring to this fix, following this template:
>
> foo should depend on bar
>
> The foo hardware is only present on bar SoCs. Hence add a
> dependency on bar, to prevent asking the user about this driver
> when configuring a kernel without bar support.
I know this is a pet peeve of yours, but asking users about one more
symbol when configuring their kernels is hardly something that requires
a Fixes tag.
Either way it's a pretty weak argument for not separating the change.
Johan
Re: [PATCH] serial: 8250: SERIAL_8250_FSL should not default to y when compile-testing
Hi Johan,
On Thu, Sep 16, 2021 at 10:46 AM Johan Hovold wrote:
> On Wed, Sep 15, 2021 at 02:56:52PM +0200, Geert Uytterhoeven wrote:
> > Commit b1442c55ce8977aa ("serial: 8250: extend compile-test coverage")
> > added compile-test support to the Freescale 16550 driver. However, as
> > SERIAL_8250_FSL is an invisible symbol, merely enabling COMPILE_TEST now
> > enables this driver.
> >
> > Fix this by making SERIAL_8250_FSL visible. Tighten the dependencies to
> > prevent asking the user about this driver when configuring a kernel
> > without appropriate Freescale SoC or ACPI support.
>
> This tightening is arguable a separate change which risk introducing
> regressions if you get it wrong and should go in a separate patch at
> least.
Getting it wrong would indeed be a regression, but not tightening
that at the same time would mean I have to send a separate patch with
a Fixes tag referring to this fix, following this template:
foo should depend on bar
The foo hardware is only present on bar SoCs. Hence add a
dependency on bar, to prevent asking the user about this driver
when configuring a kernel without bar support.
> > Fixes: b1442c55ce8977aa ("serial: 8250: extend compile-test coverage")
> > Signed-off-by: Geert Uytterhoeven
> > ---
> > Yes, it's ugly, but I see no better solution. Do you?
> >
> > drivers/tty/serial/8250/Kconfig | 8 ++--
> > 1 file changed, 6 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/tty/serial/8250/Kconfig
> > b/drivers/tty/serial/8250/Kconfig
> > index 808268edd2e82a45..a2978b31144e94f2 100644
> > --- a/drivers/tty/serial/8250/Kconfig
> > +++ b/drivers/tty/serial/8250/Kconfig
> > @@ -361,9 +361,13 @@ config SERIAL_8250_BCM2835AUX
> > If unsure, say N.
> >
> > config SERIAL_8250_FSL
> > - bool
> > + bool "Freescale 16550-style UART support (8250 based driver)"
> > depends on SERIAL_8250_CONSOLE
> > - default PPC || ARM || ARM64 || COMPILE_TEST
> > + depends on FSL_SOC || ARCH_LAYERSCAPE || SOC_LS1021A || (ARM64 &&
> > ACPI) || COMPILE_TEST
> > + default FSL_SOC || ARCH_LAYERSCAPE || SOC_LS1021A || (ARM64 && ACPI)
>
> I'd suggest just doing
>
> bool "Freescale 16550-style UART support (8250 based driver)"
> depends on SERIAL_8250_CONSOLE
> default PPC || ARM || ARM64
>
> Since neither of the symbols you add to that "depends on" line is an
> actual build or runtime dependency.
They are.
> Then you can refine the "default" line in a follow up (or argue why you
> think there should be a "depends on FSL_SOC || ...").
>
> > + help
> > + Selecting this option will add support for the 16550-style serial
> > + port hardware found on Freescale SoCs.
> >
> > config SERIAL_8250_DW
> > tristate "Support for Synopsys DesignWare 8250 quirks"
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
Re: [PATCH] serial: 8250: SERIAL_8250_FSL should not default to y when compile-testing
On Wed, Sep 15, 2021 at 02:56:52PM +0200, Geert Uytterhoeven wrote:
> Commit b1442c55ce8977aa ("serial: 8250: extend compile-test coverage")
> added compile-test support to the Freescale 16550 driver. However, as
> SERIAL_8250_FSL is an invisible symbol, merely enabling COMPILE_TEST now
> enables this driver.
>
> Fix this by making SERIAL_8250_FSL visible. Tighten the dependencies to
> prevent asking the user about this driver when configuring a kernel
> without appropriate Freescale SoC or ACPI support.
This tightening is arguable a separate change which risk introducing
regressions if you get it wrong and should go in a separate patch at
least.
> Fixes: b1442c55ce8977aa ("serial: 8250: extend compile-test coverage")
> Signed-off-by: Geert Uytterhoeven
> ---
> Yes, it's ugly, but I see no better solution. Do you?
>
> drivers/tty/serial/8250/Kconfig | 8 ++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
> index 808268edd2e82a45..a2978b31144e94f2 100644
> --- a/drivers/tty/serial/8250/Kconfig
> +++ b/drivers/tty/serial/8250/Kconfig
> @@ -361,9 +361,13 @@ config SERIAL_8250_BCM2835AUX
> If unsure, say N.
>
> config SERIAL_8250_FSL
> - bool
> + bool "Freescale 16550-style UART support (8250 based driver)"
> depends on SERIAL_8250_CONSOLE
> - default PPC || ARM || ARM64 || COMPILE_TEST
> + depends on FSL_SOC || ARCH_LAYERSCAPE || SOC_LS1021A || (ARM64 && ACPI)
> || COMPILE_TEST
> + default FSL_SOC || ARCH_LAYERSCAPE || SOC_LS1021A || (ARM64 && ACPI)
I'd suggest just doing
bool "Freescale 16550-style UART support (8250 based driver)"
depends on SERIAL_8250_CONSOLE
default PPC || ARM || ARM64
Since neither of the symbols you add to that "depends on" line is an
actual build or runtime dependency.
Then you can refine the "default" line in a follow up (or argue why you
think there should be a "depends on FSL_SOC || ...").
> + help
> + Selecting this option will add support for the 16550-style serial
> + port hardware found on Freescale SoCs.
>
> config SERIAL_8250_DW
> tristate "Support for Synopsys DesignWare 8250 quirks"
Johan
