[PATCH ath-next] wifi: ath12k: reset REOQ LUT addresses before firmware stop

[Baochen Qiang]

On 6/19/2026 8:07 PM, Aishwarya R wrote:
> During module removal, REOQ LUT cleanup writes 0 to the REOQ/ML-REOQ
> LUT address registers. That cleanup runs from ath12k_core_stop(),
> after ath12k_qmi_firmware_stop() has already stopped the
> firmware (mode OFF), so the register writes can hit an invalid target
> access.
> 
> Move the REOQ LUT register reset before ath12k_qmi_firmware_stop(),
> so the registers are cleared before stopping the firmware,
> while register access is still valid.
> 
> Additionally, handle the error path where firmware-ready setup fails
> after LUT programming but before core_stop() is reached, ensuring the
> registers are properly reset in that case as well.
> 
> On the crash-recovery path, ath12k_core_reconfigure_on_crash() calls
> ath12k_core_qmi_firmware_ready(), which re-enters ath12k_dp_setup()
> and ath12k_dp_reoq_lut_setup(), so the LUT registers are reprogrammed
> before use and stale values do not persist across recovery.
> 
> There is a brief window between the crash and when the LUT registers
> are reprogrammed during recovery, during which the registers still hold
> the freed DMA memory addresses. This is safe because the device is
> non-functional in that window and will not initiate any DMA access
> until firmware is restarted and the registers are reprogrammed.
> 
> No functional issue has been observed so far due to this sequence.
> However, this change proactively avoids potential issues such as
> invalid register accesses after firmware stop during module
> removal and error handling.
> 
> Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.6-01243-QCAHKSWPL_SILICONZ-1
> 
> Co-developed-by: P Praneesh <praneesh.p at oss.qualcomm.com>
> Signed-off-by: P Praneesh <praneesh.p at oss.qualcomm.com>
> Signed-off-by: Aishwarya R <aishwarya.r at oss.qualcomm.com>

Reviewed-by: Baochen Qiang <baochen.qiang at oss.qualcomm.com>