ipc: ipc4: dai: do not set the direction bit for UAOL

[ujfalusi]

The link_config computed here is handed to the UAOL driver as the stream channel map and written to UAOLxPCMSyCM. On ACE 2.x and later that register only defines the lchan, hchan and strm fields, its two upper bits are reserved, and union hdalink_cfg keeps the direction in the topmost of them.

Setting the direction therefore wrote a reserved bit for every capture stream, after which the link transferred no data at all and reported no error. Playback was unaffected because its direction is zero.

The link does not need to be told the direction: transmit and receive streams have separate indices, so the stream already implies it.

Fixes: ddd5c64 ("dai: uaol: add support for Intel UAOL")

[Copilot]

Pull request overview

Removes programming of the dir (direction) bit in the UAOL HD-A link configuration built by dai_set_link_hda_config() (IPC4 path), because on ACE 2.x+ the UAOLxPCMSyCM register reserves the upper bits and the stream index already implies direction. This prevents capture streams from silently failing due to writing a reserved bit.

Changes:

• Stop setting link_cfg.part.dir for SOF_DAI_INTEL_UAOL link config (leave it at 0 via link_cfg.full = 0).
• Add an in-code comment clarifying that UAOLxPCMSyCM has no direction bit and the stream selects direction.

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