From c1a792a6eea42d88a99e6ace215b22fbdb76c7b6 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Thu, 28 Oct 2010 20:31:47 +0200 Subject: [PATCH] hwmon: (w83795) Avoid reading the same register twice Shorten driver load time by avoiding duplicate register access during initialization. This saves 112 ms on modprobe on my test system. Signed-off-by: Jean Delvare --- drivers/hwmon/w83795.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/hwmon/w83795.c b/drivers/hwmon/w83795.c index fd70a7b46295..aea3275f5dae 100644 --- a/drivers/hwmon/w83795.c +++ b/drivers/hwmon/w83795.c @@ -1986,6 +1986,9 @@ static int w83795_probe(struct i2c_client *client, data->in[i][IN_READ] = tmp; } for (i = 0; i < IN_LSB_REG_NUM; i++) { + if ((i == 2 && data->chip_type == w83795adg) || + (i >= 4 && !(data->has_in & (1 << (i + 11))))) + continue; data->in_lsb[i][IN_MAX] = w83795_read(client, IN_LSB_REG(i, IN_MAX)); data->in_lsb[i][IN_LOW] = @@ -1995,13 +1998,17 @@ static int w83795_probe(struct i2c_client *client, /* First update fan and limits */ for (i = 0; i < ARRAY_SIZE(data->fan); i++) { + /* Each register contains LSB for 2 fans, but we want to + * read it only once to save time */ + if ((i & 1) == 0 && (data->has_fan & (3 << i))) + tmp = w83795_read(client, W83795_REG_FAN_MIN_LSB(i)); + if (!(data->has_fan & (1 << i))) continue; data->fan_min[i] = w83795_read(client, W83795_REG_FAN_MIN_HL(i)) << 4; data->fan_min[i] |= - (w83795_read(client, W83795_REG_FAN_MIN_LSB(i)) >> - W83795_REG_FAN_MIN_LSB_SHIFT(i)) & 0x0F; + (tmp >> W83795_REG_FAN_MIN_LSB_SHIFT(i)) & 0x0F; data->fan[i] = w83795_read(client, W83795_REG_FAN(i)) << 4; data->fan[i] |= (w83795_read(client, W83795_REG_VRLSB) >> 4) & 0x0F; -- 2.20.1