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From:   Benjamin Gaignard <benjamin.gaignard@collabora.com>
To:     shawnguo@kernel.org, s.hauer@pengutronix.de, kernel@pengutronix.de,
        festevam@gmail.com, linux-imx@nxp.com
Cc:     linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        kernel@collabora.com,
        Benjamin Gaignard <benjamin.gaignard@collabora.com>
Subject: [PATCH v3] soc: imx: imx8m-blk-ctrl: Defer probe if 'bus' genpd is not yet ready
Date:   Mon, 19 Sep 2022 14:13:02 +0200
Message-Id: <20220919121302.597993-1-benjamin.gaignard@collabora.com>
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Depending of the boot sequence 'bus' genpd could be probed after imx8m-blk-ctrl
which led driver probe to fail. Change the returned error to allow
to defer the probe in this case.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
---
v3:
- only return -EPROBE_DEFER if 'bus' device hasn't be found.

v2:
- keep dev_err_probe only change the return value.

 drivers/soc/imx/imx8m-blk-ctrl.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/soc/imx/imx8m-blk-ctrl.c b/drivers/soc/imx/imx8m-blk-ctrl.c
index dff7529268e4..1c195e9e8895 100644
--- a/drivers/soc/imx/imx8m-blk-ctrl.c
+++ b/drivers/soc/imx/imx8m-blk-ctrl.c
@@ -214,9 +214,14 @@ static int imx8m_blk_ctrl_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	bc->bus_power_dev = genpd_dev_pm_attach_by_name(dev, "bus");
-	if (IS_ERR(bc->bus_power_dev))
-		return dev_err_probe(dev, PTR_ERR(bc->bus_power_dev),
-				     "failed to attach power domain \"bus\"\n");
+	if (IS_ERR(bc->bus_power_dev)) {
+		if (PTR_ERR(bc->bus_power_dev) == -ENODEV)
+			return dev_err_probe(dev, -EPROBE_DEFER,
+					     "failed to attach power domain \"bus\"\n");
+		else
+			return dev_err_probe(dev, PTR_ERR(bc->bus_power_dev),
+					     "failed to attach power domain \"bus\"\n");
+	}
 
 	for (i = 0; i < bc_data->num_domains; i++) {
 		const struct imx8m_blk_ctrl_domain_data *data = &bc_data->domains[i];
-- 
2.32.0