[PATCHv2] irqchip/qcom-mpm: Fix missing mailbox TX done acknowledgment

[jassisinghbrar]

From: Jassi Brar <jassisinghbrar@xxxxxxxxx>

The mbox_client for qcom-mpm sends NULL doorbell messages via
mbox_send_message() but never signals TX completion.
Set knows_txdone=true and call mbox_client_txdone() after a
successful send, matching the pattern used by other Qualcomm
mailbox clients (smp2p, smsm, qcom_aoss etc).

Fixes: a6199bb514d8a6 "irqchip: Add Qualcomm MPM controller driver"
Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Signed-off-by: Jassi Brar <jassisinghbrar@xxxxxxxxx>
---
 drivers/irqchip/irq-qcom-mpm.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/irqchip/irq-qcom-mpm.c b/drivers/irqchip/irq-qcom-mpm.c
index 83f31ea657b7..181320528a47 100644
--- a/drivers/irqchip/irq-qcom-mpm.c
+++ b/drivers/irqchip/irq-qcom-mpm.c
@@ -306,6 +306,8 @@ static int mpm_pd_power_off(struct generic_pm_domain *genpd)
 	if (ret < 0)
 		return ret;
 
+	mbox_client_txdone(priv->mbox_chan, 0);
+
 	return 0;
 }
 
@@ -434,6 +436,7 @@ static int qcom_mpm_probe(struct platform_device *pdev, struct device_node *pare
 	}
 
 	priv->mbox_client.dev = dev;
+	priv->mbox_client.knows_txdone = true;
 	priv->mbox_chan = mbox_request_channel(&priv->mbox_client, 0);
 	if (IS_ERR(priv->mbox_chan)) {
 		ret = PTR_ERR(priv->mbox_chan);
-- 
2.43.0