Commit 8fddfb39 authored Apr 10, 2018 by Jia-Ju Bai Committed by Andy Shevchenko Apr 23, 2018

platform: x86: intel_scu_ipc: Replace mdelay with usleep_range in intel_scu_ipc_i2c_cntrl



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@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

parent de15b94f

drivers/platform/x86/intel_scu_ipc.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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,