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 [off-list ref] wrote:

quoted

On Wed, Sep 15, 2021 at 02:56:52PM +0200, Geert Uytterhoeven wrote:

quoted

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