Commit d944b27d authored by Kai-Heng Feng's avatar Kai-Heng Feng Committed by Wolfram Sang
Browse files

i2c: nvidia-gpu: Handle timeout correctly in gpu_i2c_check_status()

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: c71bcdcb

 ("i2c: add i2c bus driver for NVIDIA GPU")
Suggested-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: default avatarKai-Heng Feng <kai.heng.feng@canonical.com>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: default avatarAjay Gupta <ajayg@nvidia.com>
Tested-by: default avatarAjay Gupta <ajayg@nvidia.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent 692b65c8
......@@ -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 gpu_i2c_dev *i2cd)
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;
}
......
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