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Subject[PATCH v2] i2c: nvidia-gpu: Handle timeout correctly in gpu_i2c_check_status()
Date
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 <kai.heng.feng@canonical.com>
---
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
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