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From: Andreas Kemnade <andreas@kemnade.info>
To: jdelvare@suse.com, linux@roeck-us.net, lgirdwood@gmail.com,
	broonie@kernel.org, linux-hwmon@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Alistair Francis <alistair@alistair23.me>
Cc: Andreas Kemnade <andreas@kemnade.info>
Subject: [PATCH RFC 1/2] hwmon: (sy7636a) fix races during probe of mfd subdevices
Date: Sat, 20 Sep 2025 13:43:10 +0200	[thread overview]
Message-ID: <20250920114311.291450-2-andreas@kemnade.info> (raw)
In-Reply-To: <20250920114311.291450-1-andreas@kemnade.info>

If regulator subdevice is not ready early enough, devm_regulator_get will
get a dummy regulator device, not the real one needed from the regulator
subdevice, so defer probe in such case.
devm_regulator_get_optional returns an error in that case.

That fixes things, but looks odd, therefore RFC.

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
---
 drivers/hwmon/sy7636a-hwmon.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/hwmon/sy7636a-hwmon.c b/drivers/hwmon/sy7636a-hwmon.c
index ed110884786b..e83d0e50c735 100644
--- a/drivers/hwmon/sy7636a-hwmon.c
+++ b/drivers/hwmon/sy7636a-hwmon.c
@@ -73,9 +73,9 @@ static int sy7636a_sensor_probe(struct platform_device *pdev)
 	if (!regmap)
 		return -EPROBE_DEFER;
 
-	regulator = devm_regulator_get(&pdev->dev, "vcom");
-	if (IS_ERR(regulator))
-		return PTR_ERR(regulator);
+	regulator = devm_regulator_get_optional(&pdev->dev, "vcom");
+	if (IS_ERR_OR_NULL(regulator))
+		return -EPROBE_DEFER;
 
 	err = regulator_enable(regulator);
 	if (err)
-- 
2.47.3


  reply	other threads:[~2025-09-20 11:43 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-09-20 11:43 [PATCH 0/2] hmwon: (sy7636a) fix regulator handling Andreas Kemnade
2025-09-20 11:43 ` Andreas Kemnade [this message]
2025-09-20 19:58   ` [PATCH RFC 1/2] hwmon: (sy7636a) fix races during probe of mfd subdevices Mark Brown
2025-09-20 21:33     ` Andreas Kemnade
2025-09-20 22:18       ` Mark Brown
2025-09-21 16:35         ` Andreas Kemnade
2025-09-24  7:00         ` Andreas Kemnade
2025-09-24  7:17           ` Guenter Roeck
2025-09-24 17:53             ` Andreas Kemnade
2025-09-24 19:16               ` Guenter Roeck
2025-09-27 18:39                 ` Jonathan Cameron
2025-10-27 20:12                   ` Andreas Kemnade
2026-01-22 14:23                 ` In-kernel hwmon read: (was: Re: [PATCH RFC 1/2] hwmon: (sy7636a) fix races during probe of mfd subdevices) Andreas Kemnade
2026-01-31 18:42                   ` Jonathan Cameron
2026-02-01 16:29                   ` In-kernel hwmon read: Guenter Roeck
2025-09-24  8:44           ` [PATCH RFC 1/2] hwmon: (sy7636a) fix races during probe of mfd subdevices Mark Brown
2025-10-27 11:30             ` Andreas Kemnade
2025-09-20 11:43 ` [PATCH 2/2] hwmon: (sy7636a) enable regulator only if needed Andreas Kemnade
2025-09-24 16:06   ` Guenter Roeck
2025-09-24 20:40     ` Andreas Kemnade
2025-09-24 21:06       ` Guenter Roeck
2025-09-24 21:58         ` Andreas Kemnade

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