Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
From:   Thierry Reding <thierry.reding@gmail.com>
To:     Jassi Brar <jassisinghbrar@gmail.com>
Cc:     Jon Hunter <jonathanh@nvidia.com>,
        Mikko Perttunen <mperttunen@nvidia.com>,
        Pekka Pessi <ppessi@nvidia.com>, linux-tegra@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] mailbox: tegra-hsp: Flush whole channel
Date:   Mon, 14 Feb 2022 16:32:56 +0100
Message-Id: <20220214153256.162261-1-thierry.reding@gmail.com>
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From: Pekka Pessi <ppessi@nvidia.com>

The txdone can re-fill the mailbox. Keep polling the mailbox during the
flush until all the messages have been delivered.

Signed-off-by: Pekka Pessi <ppessi@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/mailbox/tegra-hsp.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/mailbox/tegra-hsp.c b/drivers/mailbox/tegra-hsp.c
index acd0675da681..78f7265039c6 100644
--- a/drivers/mailbox/tegra-hsp.c
+++ b/drivers/mailbox/tegra-hsp.c
@@ -412,6 +412,11 @@ static int tegra_hsp_mailbox_flush(struct mbox_chan *chan,
 		value = tegra_hsp_channel_readl(ch, HSP_SM_SHRD_MBOX);
 		if ((value & HSP_SM_SHRD_MBOX_FULL) == 0) {
 			mbox_chan_txdone(chan, 0);
+
+			/* Wait until channel is empty */
+			if (chan->active_req != NULL)
+				continue;
+
 			return 0;
 		}
 
-- 
2.35.1