linux-kernel - [PATCH v2 2/3] leds: leds-lp5569: Better handle enabling clock internal setting

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240712004556.15601-2-ansuelsmth@gmail.com>
Date: Fri, 12 Jul 2024 02:45:53 +0200
From: Christian Marangi <ansuelsmth@...il.com>
To: Pavel Machek <pavel@....cz>,
	Lee Jones <lee@...nel.org>,
	linux-leds@...r.kernel.org,
	linux-kernel@...r.kernel.org
Cc: Christian Marangi <ansuelsmth@...il.com>
Subject: [PATCH v2 2/3] leds: leds-lp5569: Better handle enabling clock internal setting

Better handle enabling clock internal setting. In further testing it was
notice that internal clock config MUST be set before clock output config
or the LED CHIP might stop working.

This wasn't documented and was actually found on devices that have 2
chip chained where one chip provide clock for the other.

Signed-off-by: Christian Marangi <ansuelsmth@...il.com>
---
 drivers/leds/leds-lp5569.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/leds/leds-lp5569.c b/drivers/leds/leds-lp5569.c
index b7a74d6c19ca..2b4f358bc63a 100644
--- a/drivers/leds/leds-lp5569.c
+++ b/drivers/leds/leds-lp5569.c
@@ -179,20 +179,25 @@ static int lp5569_post_init_device(struct lp55xx_chip *chip)
 
 	val = LP5569_DEFAULT_CONFIG;
 	val |= FIELD_PREP(LP5569_CP_MODE_MASK, chip->pdata->charge_pump_mode);
+	ret = lp55xx_write(chip, LP5569_REG_MISC, val);
+	if (ret)
+		return ret;
 
 	if (chip->pdata->clock_mode == LP55XX_CLOCK_INT) {
+		/* Internal clock MUST be configured before CLK output */
+		ret = lp55xx_update_bits(chip, LP5569_REG_MISC,
+					 LP5569_INTERNAL_CLK,
+					 LP5569_INTERNAL_CLK);
+		if (ret)
+			return ret;
+
 		ret = lp55xx_update_bits(chip, LP5569_REG_IO_CONTROL,
 					 LP5569_CLK_OUTPUT,
 					 LP5569_CLK_OUTPUT);
 		if (ret)
 			return ret;
-
-		val |= LP5569_INTERNAL_CLK;
 	}
 
-	ret = lp55xx_write(chip, LP5569_REG_MISC, val);
-	if (ret)
-		return ret;
 
 	return lp5569_init_program_engine(chip);
 }
-- 
2.45.2