Re: [PATCH v2] net: qrtr: Send HELLO message on endpoint register

On Fri, Aug 07, 2026 at 07:23:04PM +0530, Pranav Mahesh Phansalkar wrote:
> From: Chris Lew <[email protected]>
> 
> HELLO is currently handled entirely by the name server (NS): it is
> sent once as a broadcast when the NS initializes, and again as a
> reply whenever the NS receives an inbound HELLO from a remote.
> 
> In a slave model, neither endpoint initiates a HELLO on its own;

What is a 'slave model'? Explain please.

> each side only replies to one it receives. Since both sides are waiting
> on the other to speak first, no HELLO is ever sent, stalling further
> communication.
> 

What about the 'say_hello()' called during qrtr_ns_init()?

> To fix this:
> - Transfer HELLO handshake ownership to the core layer.
> - Schedule a work item on endpoint registration to send a HELLO once
>   the name server is bound, retrying on failure.
> - Enforce HELLO-first ordering by dropping non-HELLO packets until
>   the HELLO is confirmed sent, using bool hello_sent guarded by
>   ep_lock to make the gate check atomic with xmit().
> - Skip nodes with nid == QRTR_EP_NID_AUTO in bcast_enqueue().
> - Remove say_hello() from the name server's ctrl_cmd_hello() handler;
>   the core layer is now the sole sender of the outbound HELLO.
> 

From the internal QMUX documentation, I can see that a node acting as a slave
should only send HELLO packet only as a response to a HELLO packet, which
contradicts with that this patch is doing.

Since the driver cannot differentiate between master/slave mode, it currently
broadcasts HELLO during initialization and sends HELLO as a response to the
HELLO packet received.

- Mani

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