From: Mikko Perttunen <mperttunen@nvidia.com>
Date: Wed, 15 Sep 2021 11:55:15 +0300
Subject: memory: tegra186-emc: Handle errors in BPMP response

Git-commit: 13324edbe9269e6fbca4d0f5146b18ef8478c958
Patch-mainline: v5.16-rc1
References: jsc#SLE-20498

The return value from tegra_bpmp_transfer indicates the success or
failure of the IPC transaction with BPMP. If the transaction
succeeded, we also need to check the actual command's result code.
Add code to do this.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Link: https://lore.kernel.org/r/20210915085517.1669675-3-mperttunen@nvidia.com
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Mian Yousaf Kaukab <ykaukab@suse.de>
---
 drivers/memory/tegra/tegra186-emc.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/memory/tegra/tegra186-emc.c b/drivers/memory/tegra/tegra186-emc.c
index d65e7c2a580b..abc0c2eeaab7 100644
--- a/drivers/memory/tegra/tegra186-emc.c
+++ b/drivers/memory/tegra/tegra186-emc.c
@@ -197,6 +197,10 @@ static int tegra186_emc_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "failed to EMC DVFS pairs: %d\n", err);
 		goto put_bpmp;
 	}
+	if (msg.rx.ret < 0) {
+		dev_err(&pdev->dev, "EMC DVFS MRQ failed: %d (BPMP error code)\n", msg.rx.ret);
+		goto put_bpmp;
+	}
 
 	emc->debugfs.min_rate = ULONG_MAX;
 	emc->debugfs.max_rate = 0;
-- 
2.31.1