Pro 14 Premium PA14250, BIOS bug audio broken after UEFI capsule firmware update

Updating the BIOS on a Dell Pro 14 Premium PA14250 (SKU 0x0CDC, board 0NGT53) via UEFI capsule update (fwupdmgr / LVFS) causes complete audio loss. The BIOS loads the wrong ACPI SSDT ("Rtl0Ssdt" for Realtek rt722 codec) instead of the correct one ("Cir1Ssdt" for Cirrus Logic cs42l43 + cs35l56). The PA14250 has Cirrus audio hardware, not Realtek.

Reflashing the same BIOS version using Dell's own F12 boot menu flasher fixes the issue. The problem seems specific to the UEFI capsule update path; it might not be reinitializing platform-specific NVRAM or configuration that controls per-SKU SSDT selection.

Affected models: Uncertain, but it seems to affect Cirrus Logic audio SKUs sharing the TarokoLnlOne BIOS image:
- Dell Pro 14 Premium PA14250 (confirmed)
- Dell Pro 13 Premium PA13250 (likely affected — same Premium line, same BIOS, Cirrus audio driver on Dell's download page)

The Realtek-audio SKUs (PB14250, PB13250, PB16250) are unaffected because "Rtl0Ssdt" is correct for them.

Environment:

- Model: Dell Pro 14 Premium PA14250, SKU 0x0CDC, board 0NGT53
- CPU: Intel Lunar Lake
- Audio hardware: Cirrus Logic cs42l43 (SoundWire) + cs35l56 (SPI, left+right speakers)
- OS: Ubuntu 24.04 with kernel 6.17.0-20-generic (HWE)
- BIOS update tool: fwupdmgr (fwupd), using UEFI capsule from LVFS

Reproduction:

1. Start with a working PA14250 with any BIOS version that has correct audio (e.g., factory-installed BIOS).
2. Run `sudo fwupdmgr update` or `sudo fwupdmgr upgrade`, which updates the BIOS via UEFI capsule.
3. Reboot. Audio is gone — only "Dummy Output" appears in PipeWire/PulseAudio.

The capsule update path (broken):

The UEFI capsule delivered via LVFS (`TarokoLnlOne_*_firmware.cab`) updates the BIOS code regions only. Dell's `UpdateCapsule()` handler does not re-run the platform initialization that detects the SKU's audio hardware and configures the SSDT selector. After the update, stale or default configuration causes the BIOS to load `Rtl0Ssdt` for all SKUs, including the Cirrus-audio PA models.

The F12 flasher path (works):

Dell's F12 boot menu flasher processes the full `.exe` (Dell PFS format), selects the correct platform image for the SKU, writes all flash regions, and runs post-flash platform initialization. This correctly configures the SSDT selection, and `Cir1Ssdt` is loaded on subsequent boots.

Evidence:

Working boot (before capsule update):
```
ACPI: SSDT 0x000000005DF64000 022BCE (v02 DELL   Cir1Ssdt 00001000 INTL 20210930)
cs42l43 sdw:0:0:01fa:4243:01: devid: 0x042a43, rev: 0xa1, otp: 0x03
Topology file: intel/sof-ipc4-tplg/sof-lnl-cs42l43-l0.tplg
cs35l56 spi-cs35l56- ;margin: 0;">Broken boot (after capsule update):
```
ACPI: SSDT 0x000000005DF77000 00FF52 (v02 DELL   Rtl0Ssdt 00001000 INTL 20210930)
soundwire sdw-master-0-0: Slave Entry not found
Topology file: intel/sof-ipc4-tplg/sof-lnl-rt722-l0.tplg
rt722-sdca sdw:0:0:025d:0722:01: DPN_PortCtrl register write failed for port 1
soundwire sdw-master-0-0: Program transport params failed: -61
```

After reflashing the same BIOS version via F12 flasher:
```
ACPI: SSDT 0x000000005DF64000 022BCE (v02 DELL   Cir1Ssdt 00001000 INTL 20210930)
cs42l43 sdw:0:0:01fa:4243:01: devid: 0x042a43, rev: 0xa1, otp: 0x03
```
Audio fully restored.

Additional details:

- The EFI variable `SndwDevTopologyConfigurationVariable` (GUID `7975600e-4c1b-4e52-b75e-1ded70341813`) was investigated. Its value (`0x0009`) is the same in both working and broken states. Manually changing it to `0x0000` had no effect. The SSDT selection appears to depend on additional configuration not exposed as a simple EFI variable.
- BIOS downgrade via fwupdmgr (from 2.11.0 back to 2.10.1) did not fix the issue — the capsule downgrade path has the same problem.
- Loading BIOS factory defaults from the BIOS setup menu did not fix the issue.
- The issue was reproduced across three different kernels (6.17.0-20-generic, 6.17.0-1017-oem, 7.0.0-14-generic from Ubuntu 26.04 daily ISO) and with updated SOF firmware — confirming it is not a kernel or driver bug.

Workaround:

Reflash the BIOS using Dell's F12 boot menu flasher:
1. Download the BIOS `.exe` from Dell's support page for the PA14250.
2. Copy it to a FAT32 USB drive or the EFI System Partition.
3. Reboot, press F12, select "BIOS Flash Update".
4. Browse to the `.exe` and flash.
5. Reboot. Audio will be restored.

Suggested fix:

Dell's `UpdateCapsule()` handler for the TarokoLnlOne platform should perform per-SKU audio topology initialization after writing the BIOS code regions, matching the behavior of the F12 flasher. Alternatively, the BIOS should detect the physical audio hardware at every boot (via SoundWire bus probe or hardware straps) rather than relying on stored configuration that can become stale after a capsule update.