From: Jia-Ju Bai <baijiaju1990@gmail.com>
To: dvhart@infradead.org, andy@infradead.org
Cc: platform-driver-x86@vger.kernel.org,
linux-kernel@vger.kernel.org, Jia-Ju Bai <baijiaju1990@gmail.com>
Subject: [PATCH] platform: x86: intel_scu_ipc: Replace mdelay with usleep_range in intel_scu_ipc_i2c_cntrl
Date: Tue, 10 Apr 2018 20:57:56 +0800 [thread overview]
Message-ID: <1523365076-31461-1-git-send-email-baijiaju1990@gmail.com> (raw)
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>
---
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
next reply other threads:[~2018-04-10 12:58 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-10 12:57 Jia-Ju Bai [this message]
2018-04-10 15:25 ` [PATCH] platform: x86: intel_scu_ipc: Replace mdelay with usleep_range in intel_scu_ipc_i2c_cntrl Andy Shevchenko
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