RE: [PATCH net-next 09/17] net: dsa: mv88e6xxx: Get Product ID when enabling RMU

[Jagielski, Jedrzej]

From: Luke Howard <lukeh@xxxxxxxx> 
Sent: Friday, July 3, 2026 9:47 AM
>
>From: Andrew Lunn <andrew@xxxxxxx>
>
>When the RMU is enabled, it is recommended to get the product ID,
>which identifies the switch. This is used as a test that communication
>with the switch actually works and the RMU can be used. If successful,
>mark the RMU usable.
>
>This completes the general infrastructure to send a request and
>process the response.
>
>Co-developed: Mattias Forsblad <mattias.forsblad@xxxxxxxxx>
>Signed-off-by: Mattias Forsblad <mattias.forsblad@xxxxxxxxx>
>Signed-off-by: Andrew Lunn <andrew@xxxxxxx>
>Signed-off-by: Luke Howard <lukeh@xxxxxxxx>
>---
> drivers/net/dsa/mv88e6xxx/chip.h |  10 +++
> drivers/net/dsa/mv88e6xxx/rmu.c  | 151 ++++++++++++++++++++++++++++++++++++++-
> drivers/net/dsa/mv88e6xxx/rmu.h  |  11 +++
> 3 files changed, 170 insertions(+), 2 deletions(-)
>
>diff --git a/drivers/net/dsa/mv88e6xxx/chip.h b/drivers/net/dsa/mv88e6xxx/chip.h
>index 940ae698659fc..07300c25cbd36 100644
>--- a/drivers/net/dsa/mv88e6xxx/chip.h
>+++ b/drivers/net/dsa/mv88e6xxx/chip.h
>@@ -346,6 +346,15 @@ struct mv88e6xxx_tcam {
> 	struct list_head entries;
> };
> 
>+enum mv88e6xxx_rmu_state {
>+	MV88E6XXX_RMU_DISABLED = 0,
>+	MV88E6XXX_RMU_ENABLED = 1,
>+	/* Reserved: a future RMU-only mode (e.g. MV88E6XXX_RMU_ONLY_ENABLED)
>+	 * may be added here to indicate a switch operating purely via RMU
>+	 * without an MDIO bus.
>+	 */

As from what i see it's not being extended within the series, can we drop
that comment and use simple bool enabled/disabled in the place of
mv88e6xxx_rmu_state?
or am I missing something and > 2 states are needed

...

>+	return dsa_inband_request(&chip->rmu_inband, skb,
>+				  (edsa ? mv88e6xxx_rmu_fill_seqno_edsa :
>+				   mv88e6xxx_rmu_fill_seqno_dsa),
>+				  resp, resp_len, timeout_ms);
>+}
>+
>+static int mv88e6xxx_rmu_get_id(struct mv88e6xxx_chip *chip)
>+{
>+	const __be16 req[4] = {
>+		MV88E6XXX_RMU_REQ_FORMAT_GET_ID,
>+		MV88E6XXX_RMU_REQ_PAD,
>+		MV88E6XXX_RMU_REQ_CODE_GET_ID,
>+		MV88E6XXX_RMU_REQ_DATA};
>+	struct mv88e6xxx_rmu_header resp;
>+	int resp_len;
>+	int ret = -1;

no need to init

>+
>+	resp_len = sizeof(resp);
>+	ret = mv88e6xxx_rmu_request(chip, req, sizeof(req),