Re: [PATCH net-next] dsa: sja1105: fix reverse dependency

On Thu, Aug 5, 2021 at 1:25 PM Vladimir Oltean [off-list ref] wrote:

On Thu, Aug 05, 2021 at 01:00:28PM +0200, Arnd Bergmann wrote:

quoted

Fixes: 566b18c8b752 ("net: dsa: sja1105: implement TX timestamping for SJA1110")
Fixes: 227d07a07ef1 ("net: dsa: sja1105: Add support for traffic through standalone ports")

The second Fixes: tag makes no sense.

Fair enough. I added this because that was when the original 'select' got added,
but of course it was not wrong at the time.

quoted

diff --git a/net/dsa/Kconfig b/net/dsa/Kconfig
index bca1b5d66df2..548285539752 100644
--- a/net/dsa/Kconfig
+++ b/net/dsa/Kconfig

@@ -138,6 +138,7 @@ config NET_DSA_TAG_LAN9303

 config NET_DSA_TAG_SJA1105
      tristate "Tag driver for NXP SJA1105 switches"
+     depends on NET_DSA_SJA1105 || !NET_DSA_SJA1105

I think I would prefer an optional "build as module if NET_DSA_SJA1105 is a module"
dependency only if NET_DSA_SJA1105_PTP is enabled. I think this is how that is
expressed:

        depends on (NET_DSA_SJA1105 && NET_DSA_SJA1105_PTP) || !NET_DSA_SJA1105 || !NET_DSA_SJA1105_PTP

Ah, I had not realized this dependency is only there when NET_DSA_SJA1105_PTP
is also enabled. I will give this a little more testing and resend
later with that change.

Do you have any opinion on whether that 'select' going the other way is still
relevant?

      Arnd