[PATCH] platform: x86: intel_scu_ipc: Replace mdelay with usleep_range in intel_scu_ipc_i2c_cntrl

From: Jia-Ju Bai
Date: Tue Apr 10 2018 - 08:58:27 EST


intel_scu_ipc_i2c_cntrl() calls mutex_lock(), which indicates
this function is not called in atomic context.

Despite never getting called from atomic context,
intel_scu_ipc_i2c_cntrl() calls mdelay to busily wait.
This is not necessary and can be replaced with usleep_range to
avoid busy waiting.

This is found by a static analysis tool named DCNS written by myself.
And I also manually check it.

Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
---
drivers/platform/x86/intel_scu_ipc.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/x86/intel_scu_ipc.c b/drivers/platform/x86/intel_scu_ipc.c
index 2c85f75..75c8fef 100644
--- a/drivers/platform/x86/intel_scu_ipc.c
+++ b/drivers/platform/x86/intel_scu_ipc.c
@@ -584,11 +584,11 @@ int intel_scu_ipc_i2c_cntrl(u32 addr, u32 *data)
if (cmd == IPC_I2C_READ) {
writel(addr, scu->i2c_base + IPC_I2C_CNTRL_ADDR);
/* Write not getting updated without delay */
- mdelay(1);
+ usleep_range(1000, 2000);
*data = readl(scu->i2c_base + I2C_DATA_ADDR);
} else if (cmd == IPC_I2C_WRITE) {
writel(*data, scu->i2c_base + I2C_DATA_ADDR);
- mdelay(1);
+ usleep_range(1000, 2000);
writel(addr, scu->i2c_base + IPC_I2C_CNTRL_ADDR);
} else {
dev_err(scu->dev,
--
1.9.1