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From: Axel Lin <axel.lin@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com>,
	"Milo(Woogyom) Kim" <milo.kim@ti.com>,
	Richard Purdie <rpurdie@rpsys.net>,
	Andrew Morton <akpm@linux-foundation.org>,
	Mark Brown <broonie@opensource.wolfsonmicro.com>,
	Liam Girdwood <lrg@ti.com>
Subject: [PATCH] leds: lm3530: fix handling of already enabled regulators
Date: Sun, 22 Apr 2012 23:11:48 +0800	[thread overview]
Message-ID: <1335107508.6261.3.camel@phoenix> (raw)

It is possible that the regulator has been previously enabled by bootloader or
kernel board initialization code. Thus, don't assume the regulator is disabled
by default. Get the correct status by regulator_is_enabled().

The leds-lm3530 driver was ignoring the initial status of the
regulator; this resulted in rdev->use_count being incremented to 2 after
calling lm3530_init_registers() in the .probe method when a regulator
was already enabled at insmod time, which made it impossible to ever
disable the regulator.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
---
 drivers/leds/leds-lm3530.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/leds/leds-lm3530.c b/drivers/leds/leds-lm3530.c
index 968fd5f..859bf04 100644
--- a/drivers/leds/leds-lm3530.c
+++ b/drivers/leds/leds-lm3530.c
@@ -397,7 +397,6 @@ static int __devinit lm3530_probe(struct i2c_client *client,
 	drvdata->client = client;
 	drvdata->pdata = pdata;
 	drvdata->brightness = LED_OFF;
-	drvdata->enable = false;
 	drvdata->led_dev.name = LM3530_LED_DEV;
 	drvdata->led_dev.brightness_set = lm3530_brightness_set;
 	drvdata->led_dev.max_brightness = MAX_BRIGHTNESS;
@@ -411,6 +410,7 @@ static int __devinit lm3530_probe(struct i2c_client *client,
 		drvdata->regulator = NULL;
 		goto err_regulator_get;
 	}
+	drvdata->enable = regulator_is_enabled(drvdata->regulator);
 
 	if (drvdata->pdata->brt_val) {
 		err = lm3530_init_registers(drvdata);
-- 
1.7.5.4




             reply	other threads:[~2012-04-22 15:11 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-04-22 15:11 Axel Lin [this message]
2012-04-23 11:09 ` [PATCH] leds: lm3530: fix handling of already enabled regulators Mark Brown
2012-04-24  2:09   ` Axel Lin
2012-04-24  6:27     ` Kim, Milo
2012-04-24  8:48       ` Axel Lin
2012-04-24 10:15         ` Kim, Milo
2012-04-24 12:35           ` Axel Lin

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