From: Kai-Heng Feng kai.heng.feng@canonical.com
commit d944b27df121e2ee854a6c2fad13d6c6300792d4 upstream.
Nvidia card may come with a "phantom" UCSI device, and its driver gets stuck in probe routine, prevents any system PM operations like suspend.
There's an unaccounted case that the target time can equal to jiffies in gpu_i2c_check_status(), let's solve that by using readl_poll_timeout() instead of jiffies comparison functions.
Fixes: c71bcdcb42a7 ("i2c: add i2c bus driver for NVIDIA GPU") Suggested-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Signed-off-by: Kai-Heng Feng kai.heng.feng@canonical.com Reviewed-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Reviewed-by: Ajay Gupta ajayg@nvidia.com Tested-by: Ajay Gupta ajayg@nvidia.com Signed-off-by: Wolfram Sang wsa@the-dreams.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/i2c/busses/i2c-nvidia-gpu.c | 18 +++++++----------- 1 file changed, 7 insertions(+), 11 deletions(-)
--- a/drivers/i2c/busses/i2c-nvidia-gpu.c +++ b/drivers/i2c/busses/i2c-nvidia-gpu.c @@ -8,6 +8,7 @@ #include <linux/delay.h> #include <linux/i2c.h> #include <linux/interrupt.h> +#include <linux/iopoll.h> #include <linux/module.h> #include <linux/pci.h> #include <linux/platform_device.h> @@ -75,20 +76,15 @@ static void gpu_enable_i2c_bus(struct gp
static int gpu_i2c_check_status(struct gpu_i2c_dev *i2cd) { - unsigned long target = jiffies + msecs_to_jiffies(1000); u32 val; + int ret;
- 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) - break; - usleep_range(500, 600); - } while (time_is_after_jiffies(target)); + ret = readl_poll_timeout(i2cd->regs + I2C_MST_CNTL, val, + !(val & I2C_MST_CNTL_CYCLE_TRIGGER) || + (val & I2C_MST_CNTL_STATUS) != I2C_MST_CNTL_STATUS_BUS_BUSY, + 500, 1000 * USEC_PER_MSEC);
- if (time_is_before_jiffies(target)) { + if (ret) { dev_err(i2cd->dev, "i2c timeout error %x\n", val); return -ETIMEDOUT; }