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| author | Caesar Wang <wxt@rock-chips.com> | 2016-05-03 10:23:50 +0800 |
|---|---|---|
| committer | Eduardo Valentin <edubezval@gmail.com> | 2016-05-17 07:28:33 -0700 |
| commit | 2fe5c1b0453c445f8a19e1a53f8297b21c2cba4c (patch) | |
| tree | 82c3dd32983051769ba6281d5fea89fde4c65e70 /drivers/thermal/rockchip_thermal.c | |
| parent | 678065d5b786763cb9f5d97673409ae32ead2314 (diff) | |
| download | lwn-2fe5c1b0453c445f8a19e1a53f8297b21c2cba4c.tar.gz lwn-2fe5c1b0453c445f8a19e1a53f8297b21c2cba4c.zip | |
thermal: rockchip: use the usleep_range instead of udelay
Documentation/timers/timers-howto.txt recommends to use
usleep_range on delays > 10usec.
The usleep_range indeed reduces CPU load, since the udelay will busy wait
for enough loop cycles to achieve the desired delay.
Fixes commit b06c52db39fd ("thermal: rockchip:
handle the power sequence for tsadc controller").
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Suggested-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Diffstat (limited to 'drivers/thermal/rockchip_thermal.c')
| -rw-r--r-- | drivers/thermal/rockchip_thermal.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/thermal/rockchip_thermal.c b/drivers/thermal/rockchip_thermal.c index 86a1ab04bf95..5d491f16a866 100644 --- a/drivers/thermal/rockchip_thermal.c +++ b/drivers/thermal/rockchip_thermal.c @@ -547,10 +547,10 @@ static void rk_tsadcv3_initialize(struct regmap *grf, void __iomem *regs, regmap_write(grf, GRF_TSADC_TESTBIT_L, GRF_TSADC_TSEN_PD_ON); mdelay(10); regmap_write(grf, GRF_TSADC_TESTBIT_L, GRF_TSADC_TSEN_PD_OFF); - udelay(100); /* The spec note says at least 15 us */ + usleep_range(15, 100); /* The spec note says at least 15 us */ regmap_write(grf, GRF_SARADC_TESTBIT, GRF_SARADC_TESTBIT_ON); regmap_write(grf, GRF_TSADC_TESTBIT_H, GRF_TSADC_TESTBIT_H_ON); - udelay(200); /* The spec note says at least 90 us */ + usleep_range(90, 200); /* The spec note says at least 90 us */ } if (tshut_polarity == TSHUT_HIGH_ACTIVE) |