remoteproc: qcom: q6v5: Avoid handling handover twice

A remoteproc could theoretically signal handover twice. This is unexpected
and would break the reference counting for the handover resources (power
domains, clocks, regulators, etc), so add a check to prevent that from
happening.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Stephan Gerhold <stephan.gerhold@linaro.org>
Link: https://lore.kernel.org/r/20250820-rproc-qcom-q6v5-fixes-v2-2-910b1a3aff71@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

drivers/remoteproc/qcom_q6v5.c

@@ -164,6 +164,11 @@ static irqreturn_t q6v5_handover_interrupt(int irq, void *data)
 {
 	struct qcom_q6v5 *q6v5 = data;
 
+	if (q6v5->handover_issued) {
+		dev_err(q6v5->dev, "Handover signaled, but it already happened\n");
+		return IRQ_HANDLED;
+	}
+
 	if (q6v5->handover)
 		q6v5->handover(q6v5);