[PATCH 2/9] kernel: change CONFIG_HW_RANDOM default to y

[Felix Fietkau]

On 29.04.23 08:08, Elliott Mitchell wrote:
> On Fri, Apr 28, 2023 at 10:29:29AM -0600, Philip Prindeville wrote:
>> Why isn't this migrating upwards into target/linux/generic/config-5.15 and target/linux/generic/config-5.10 in that case?
>> 
>> And for the platforms where it was turned off, like target/linux/armvirt/32/config-5.15, why isn't that staying unchanged?
> 
> I'm guessing you're unaware of a subtlety of how the .config system
> actually works.  Take a second look, some handy examples:
> 
>> > On Apr 22, 2023, at 11:46 AM, Elliott Mitchell <ehem+openwrt at m5p.com> wrote:
> 
>> > diff --git a/target/linux/armvirt/32/config-5.10 b/target/linux/armvirt/32/config-5.10
>> > index 3c6443bcbf..2f7cd03b5f 100644
>> > --- a/target/linux/armvirt/32/config-5.10
>> > +++ b/target/linux/armvirt/32/config-5.10
>> > @@ -47,6 +47,7 @@ CONFIG_EDAC_ATOMIC_SCRUB=y
>> > CONFIG_GENERIC_VDSO_32=y
>> > CONFIG_HARDEN_BRANCH_PREDICTOR=y
>> > CONFIG_HAVE_SMP=y
>> > +CONFIG_HW_RANDOM=n
>> > CONFIG_HZ_FIXED=0
>> > CONFIG_HZ_PERIODIC=y
>> > CONFIG_MIGHT_HAVE_CACHE_L2X0=y
>> > diff --git a/target/linux/armvirt/32/config-5.15 b/target/linux/armvirt/32/config-5.15
>> > index bf6e2a5cde..bb2a7a320f 100644
>> > --- a/target/linux/armvirt/32/config-5.15
>> > +++ b/target/linux/armvirt/32/config-5.15
>> > @@ -49,6 +49,7 @@ CONFIG_GENERIC_IRQ_MULTI_HANDLER=y
>> > CONFIG_GENERIC_VDSO_32=y
>> > CONFIG_HARDEN_BRANCH_PREDICTOR=y
>> > CONFIG_HAVE_SMP=y
>> > +CONFIG_HW_RANDOM=n
>> > CONFIG_HZ_FIXED=0
>> > CONFIG_HZ_PERIODIC=y
>> > CONFIG_MIGHT_HAVE_CACHE_L2X0=y
> 
> 
>> > diff --git a/target/linux/armvirt/64/config-5.10 b/target/linux/armvirt/64/config-5.10
>> > index 275fe4571d..af46939ad2 100644
>> > --- a/target/linux/armvirt/64/config-5.10
>> > +++ b/target/linux/armvirt/64/config-5.10
>> > @@ -102,7 +102,6 @@ CONFIG_GPIO_GENERIC=y
>> > CONFIG_GPIO_GENERIC_PLATFORM=y
>> > CONFIG_HDMI=y
>> > CONFIG_HOLES_IN_ZONE=y
>> > -CONFIG_HW_RANDOM=y
>> > CONFIG_HW_RANDOM_VIRTIO=y
>> > CONFIG_I2C=y
>> > CONFIG_I2C_ALGOBIT=y
>> > diff --git a/target/linux/armvirt/64/config-5.15 b/target/linux/armvirt/64/config-5.15
>> > index 19ae3dc0cf..88f2f64cde 100644
>> > --- a/target/linux/armvirt/64/config-5.15
>> > +++ b/target/linux/armvirt/64/config-5.15
>> > @@ -103,7 +103,6 @@ CONFIG_GENERIC_FIND_FIRST_BIT=y
>> > CONFIG_GPIO_GENERIC=y
>> > CONFIG_GPIO_GENERIC_PLATFORM=y
>> > CONFIG_HDMI=y
>> > -CONFIG_HW_RANDOM=y
>> > CONFIG_HW_RANDOM_ARM_SMCCC_TRNG=y
>> > CONFIG_HW_RANDOM_VIRTIO=y
>> > CONFIG_I2C=y
>> > diff --git a/target/linux/ath25/config-5.10 b/target/linux/ath25/config-5.10
>> > index ef764820e4..41e65c72ad 100644
> 
> 
>> > diff --git a/target/linux/generic/config-5.10 b/target/linux/generic/config-5.10
>> > index f6f1fb0278..853c13852d 100644
>> > --- a/target/linux/generic/config-5.10
>> > +++ b/target/linux/generic/config-5.10
>> > @@ -2343,7 +2343,7 @@ CONFIG_HPET_MMAP_DEFAULT=y
>> > # CONFIG_HWSPINLOCK is not set
>> > # CONFIG_HWSPINLOCK_OMAP is not set
>> > CONFIG_HW_PERF_EVENTS=y
>> > -# CONFIG_HW_RANDOM is not set
>> > +CONFIG_HW_RANDOM=y
>> > # CONFIG_HW_RANDOM_AMD is not set
>> > # CONFIG_HW_RANDOM_ATMEL is not set
>> > # CONFIG_HW_RANDOM_BA431 is not set
>> > diff --git a/target/linux/generic/config-5.15 b/target/linux/generic/config-5.15
>> > index ac75a480a1..bf38732b31 100644
>> > --- a/target/linux/generic/config-5.15
>> > +++ b/target/linux/generic/config-5.15
>> > @@ -2444,7 +2444,7 @@ CONFIG_HPET_MMAP_DEFAULT=y
>> > # CONFIG_HWSPINLOCK is not set
>> > # CONFIG_HWSPINLOCK_OMAP is not set
>> > CONFIG_HW_PERF_EVENTS=y
>> > -# CONFIG_HW_RANDOM is not set
>> > +CONFIG_HW_RANDOM=y
>> > # CONFIG_HW_RANDOM_AMD is not set
>> > # CONFIG_HW_RANDOM_ARM_SMCCC_TRNG is not set
>> > # CONFIG_HW_RANDOM_ATMEL is not set
> 
> armvirt/32 previously had it off and it is still off.  armvirt/64
> previously had it on and it is still on.
> 
> Most similar systems would treat "# <option> is not set" as undefined or
> no preference (use the default value).  The Linux kernel system treats
> this as "no" due to the history of the system.  Yet it also honors "n"
> as "no".
> 
> I tend to prefer "n" as it hints at a value being deliberately chosen,
> instead of being left unset/undefined.
Please use the same syntax as in the rest of the file. Occasionally 
kconfig.pl will be used to add entries or re-sort the file, and 
mis-matching the existing style will cause spurious extra changes in 
that case.
Also, please fix your mail server, I get bounces when sending to you.

- Felix