From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kai-Heng Feng Subject: [PATCH v2] i2c: nvidia-gpu: Handle timeout correctly in gpu_i2c_check_status() Date: Tue, 24 Mar 2020 21:07:12 +0800 Message-ID: <20200324130712.12289-1-kai.heng.feng@canonical.com> Return-path: Sender: linux-kernel-owner@vger.kernel.org To: ajayg@nvidia.com Cc: Kai-Heng Feng , Andy Shevchenko , Wolfram Sang , "open list:I2C CONTROLLER DRIVER FOR NVIDIA GPU" , open list List-Id: linux-i2c@vger.kernel.org Nvidia card may come with a "phantom" UCSI device, and its driver gets stuck in probe routine, prevents any system PM operations like suspend. When the target time equals to jiffies, it's not included by time_is_before_jiffies(). So let's use a boolean to make sure the operation is done or timeout. Fixes: c71bcdcb42a7 ("i2c: add i2c bus driver for NVIDIA GPU") Signed-off-by: Kai-Heng Feng --- v2: - Use a boolean to make sure the operation is timeout or not. drivers/i2c/busses/i2c-nvidia-gpu.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/i2c/busses/i2c-nvidia-gpu.c b/drivers/i2c/busses/i2c-nvidia-gpu.c index 62e18b4db0ed..bdb48600af0e 100644 --- a/drivers/i2c/busses/i2c-nvidia-gpu.c +++ b/drivers/i2c/busses/i2c-nvidia-gpu.c @@ -77,18 +77,20 @@ static int gpu_i2c_check_status(struct gpu_i2c_dev *i2cd) { unsigned long target = jiffies + msecs_to_jiffies(1000); u32 val; + bool done = false; do { val = readl(i2cd->regs + I2C_MST_CNTL); - if (!(val & I2C_MST_CNTL_CYCLE_TRIGGER)) - break; - if ((val & I2C_MST_CNTL_STATUS) != - I2C_MST_CNTL_STATUS_BUS_BUSY) + if (!(val & I2C_MST_CNTL_CYCLE_TRIGGER) + || (val & I2C_MST_CNTL_STATUS) != + I2C_MST_CNTL_STATUS_BUS_BUSY) { + done = true; break; + } usleep_range(500, 600); } while (time_is_after_jiffies(target)); - if (time_is_before_jiffies(target)) { + if (!done) { dev_err(i2cd->dev, "i2c timeout error %x\n", val); return -ETIMEDOUT; } -- 2.17.1