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From: Lee Jones <lee.jones@linaro.org>
To: lee.jones@linaro.org
Cc: linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, Johan Hovold <jhovold@gmail.com>
Subject: [PATCH 2/5] mfd: lm3533-ctrlbank: Cap BRIGHTNESS_MAX to 127 since API uses u8 as carrier
Date: Mon, 29 Jun 2020 13:32:12 +0100	[thread overview]
Message-ID: <20200629123215.1014747-3-lee.jones@linaro.org> (raw)
In-Reply-To: <20200629123215.1014747-1-lee.jones@linaro.org>

Since its conception in 2012 brightness has been artificially capped
at 127 since the variable carrying the value is u8.  We could go to
the trouble of changing the whole API (crossing 3 different subsystems),
but clearly this hasn't bothered anyone in the best part of a decade.

Simply, cap BRIGHTNESS_MAX to 127 instead (for now at least).

Fixes the following W=1 warning(s):

 drivers/mfd/lm3533-ctrlbank.c: In function ‘lm3533_ctrlbank_set_brightness’:
 drivers/mfd/lm3533-ctrlbank.c:98:10: warning: comparison is always false due to limited range of data type [-Wtype-limits]
 98 | if (val > LM3533_##_NAME##_MAX) | ^
 drivers/mfd/lm3533-ctrlbank.c:125:1: note: in expansion of macro ‘lm3533_ctrlbank_set’
 125 | lm3533_ctrlbank_set(brightness, BRIGHTNESS);
 | ^~~~~~~~~~~~~~~~~~~

Cc: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 drivers/mfd/lm3533-ctrlbank.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mfd/lm3533-ctrlbank.c b/drivers/mfd/lm3533-ctrlbank.c
index 34fba06ec7057..348ce67453092 100644
--- a/drivers/mfd/lm3533-ctrlbank.c
+++ b/drivers/mfd/lm3533-ctrlbank.c
@@ -17,7 +17,7 @@
 #define LM3533_MAX_CURRENT_MAX		29800
 #define LM3533_MAX_CURRENT_STEP		800
 
-#define LM3533_BRIGHTNESS_MAX		255
+#define LM3533_BRIGHTNESS_MAX		127  /* Capped by API - could be up to 255 */
 #define LM3533_PWM_MAX			0x3f
 
 #define LM3533_REG_PWM_BASE		0x14
-- 
2.25.1


WARNING: multiple messages have this Message-ID (diff)
From: Lee Jones <lee.jones@linaro.org>
To: lee.jones@linaro.org
Cc: Johan Hovold <jhovold@gmail.com>,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/5] mfd: lm3533-ctrlbank: Cap BRIGHTNESS_MAX to 127 since API uses u8 as carrier
Date: Mon, 29 Jun 2020 13:32:12 +0100	[thread overview]
Message-ID: <20200629123215.1014747-3-lee.jones@linaro.org> (raw)
In-Reply-To: <20200629123215.1014747-1-lee.jones@linaro.org>

Since its conception in 2012 brightness has been artificially capped
at 127 since the variable carrying the value is u8.  We could go to
the trouble of changing the whole API (crossing 3 different subsystems),
but clearly this hasn't bothered anyone in the best part of a decade.

Simply, cap BRIGHTNESS_MAX to 127 instead (for now at least).

Fixes the following W=1 warning(s):

 drivers/mfd/lm3533-ctrlbank.c: In function ‘lm3533_ctrlbank_set_brightness’:
 drivers/mfd/lm3533-ctrlbank.c:98:10: warning: comparison is always false due to limited range of data type [-Wtype-limits]
 98 | if (val > LM3533_##_NAME##_MAX) | ^
 drivers/mfd/lm3533-ctrlbank.c:125:1: note: in expansion of macro ‘lm3533_ctrlbank_set’
 125 | lm3533_ctrlbank_set(brightness, BRIGHTNESS);
 | ^~~~~~~~~~~~~~~~~~~

Cc: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 drivers/mfd/lm3533-ctrlbank.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mfd/lm3533-ctrlbank.c b/drivers/mfd/lm3533-ctrlbank.c
index 34fba06ec7057..348ce67453092 100644
--- a/drivers/mfd/lm3533-ctrlbank.c
+++ b/drivers/mfd/lm3533-ctrlbank.c
@@ -17,7 +17,7 @@
 #define LM3533_MAX_CURRENT_MAX		29800
 #define LM3533_MAX_CURRENT_STEP		800
 
-#define LM3533_BRIGHTNESS_MAX		255
+#define LM3533_BRIGHTNESS_MAX		127  /* Capped by API - could be up to 255 */
 #define LM3533_PWM_MAX			0x3f
 
 #define LM3533_REG_PWM_BASE		0x14
-- 
2.25.1


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  parent reply	other threads:[~2020-06-29 21:18 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-29 12:32 [PATCH 0/5] Last batch of W=1 warning fixes in MFD Lee Jones
2020-06-29 12:32 ` Lee Jones
2020-06-29 12:32 ` [PATCH 1/5] mfd: si476x-cmd: Add missing documentation for si476x_cmd_fm_rds_status()'s arg 'report' Lee Jones
2020-06-29 12:32   ` Lee Jones
2020-06-29 12:32 ` Lee Jones [this message]
2020-06-29 12:32   ` [PATCH 2/5] mfd: lm3533-ctrlbank: Cap BRIGHTNESS_MAX to 127 since API uses u8 as carrier Lee Jones
2020-06-29 12:51   ` Johan Hovold
2020-06-29 12:51     ` Johan Hovold
2020-06-29 13:25     ` Lee Jones
2020-06-29 13:25       ` Lee Jones
2020-06-30  8:38       ` Johan Hovold
2020-06-30  8:38         ` Johan Hovold
2020-06-29 12:32 ` [PATCH 3/5] mfd: rave-sp: Fix mistake in 'struct rave_sp_deframer's kerneldoc Lee Jones
2020-06-29 12:32   ` Lee Jones
2020-06-29 12:32 ` [PATCH 4/5] mfd: sprd-sc27xx-spi: Fix divide by zero when allocating register offset/mask Lee Jones
2020-06-29 12:32   ` Lee Jones
2020-06-29 13:06   ` Johan Hovold
2020-06-29 13:06     ` Johan Hovold
2020-06-29 14:01     ` Lee Jones
2020-06-29 14:01       ` Lee Jones
2020-06-29 14:35       ` Baolin Wang
2020-06-29 14:35         ` Baolin Wang
2020-06-29 14:43         ` Johan Hovold
2020-06-29 14:43           ` Johan Hovold
2020-06-29 15:08           ` Baolin Wang
2020-06-29 15:08             ` Baolin Wang
2020-06-29 15:45             ` Lee Jones
2020-06-29 15:45               ` Lee Jones
2020-07-01  9:15   ` [PATCH] mfd: sprd-sc27xx-spi: Fix-up bogus IRQ register offset and mask setting Lee Jones
2020-07-01  9:15     ` Lee Jones
2020-07-01 14:10     ` Baolin Wang
2020-07-01 14:10       ` Baolin Wang
2020-06-29 12:32 ` [PATCH 5/5] mfd: axp20x-i2c: Do not define 'struct acpi_device_id' when !CONFIG_ACPI Lee Jones
2020-06-29 12:32   ` Lee Jones
2020-06-29 15:38   ` Chen-Yu Tsai
2020-06-29 15:38     ` Chen-Yu Tsai
2020-07-06  7:31     ` Lee Jones
2020-07-06  7:31       ` Lee Jones
2020-07-01  6:59   ` [PATCH v2] mfd: axp20x-i2c: Tell the compiler that ACPI functions may not be used Lee Jones
2020-07-01  6:59     ` Lee Jones
2020-07-01  8:38     ` Chen-Yu Tsai
2020-07-01  8:38       ` Chen-Yu Tsai

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