[SRU][N:linux-bluefield][PATCH v1 3/4] mlxbf_gige: return EPROBE_DEFER if PHY IRQ is not available

[Chris Babroski]

From: David Thompson <davthompson at nvidia.com>

BugLink: https://bugs.launchpad.net/bugs/2120950

The message "Error getting PHY irq. Use polling instead"
is emitted when the mlxbf_gige driver is loaded by the
kernel before the associated gpio-mlxbf driver, and thus
the call to get the PHY IRQ fails since it is not yet
available. The driver probe() must return -EPROBE_DEFER
if acpi_dev_gpio_irq_get_by() returns the same.

Fixes: 6c2a6ddca763 ("net: mellanox: mlxbf_gige: Replace non-standard interrupt handling")
Signed-off-by: David Thompson <davthompson at nvidia.com>
Reviewed-by: Asmaa Mnebhi <asmaa at nvidia.com>
Reviewed-by: Simon Horman <horms at kernel.org>
Link: https://patch.msgid.link/20250618135902.346-1-davthompson@nvidia.com
Signed-off-by: Jakub Kicinski <kuba at kernel.org>
(backported from commit e7ea5f5b1858ddb96b152584d5fe06e6fc623e89)
[cbabroski: resolved cherry-pick merge conflict by keeping old use of
            "phy-gpios" instead of "phy", but using new EPROBE_DEFER
            error handling.]
Signed-off-by: Chris Babroski <cbabroski at nvidia.com>
---
 drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_main.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_main.c b/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_main.c
index a49cc58f697c..406b66223e29 100644
--- a/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_main.c
+++ b/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_main.c
@@ -447,8 +447,10 @@ static int mlxbf_gige_probe(struct platform_device *pdev)
 	priv->llu_plu_irq = platform_get_irq(pdev, MLXBF_GIGE_LLU_PLU_INTR_IDX);
 
 	phy_irq = acpi_dev_gpio_irq_get_by(ACPI_COMPANION(&pdev->dev), "phy-gpios", 0);
-	if (phy_irq < 0) {
-		dev_err(&pdev->dev, "Error getting PHY irq. Use polling instead");
+	if (phy_irq == -EPROBE_DEFER) {
+		err = -EPROBE_DEFER;
+		goto out;
+	} else if (phy_irq < 0) {
 		phy_irq = PHY_POLL;
 	}
 
-- 
2.34.1