summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorKai-Heng Feng <kai.heng.feng@canonical.com>2020-03-24 23:28:11 +0800
committerWolfram Sang <wsa@the-dreams.de>2020-03-24 22:40:55 +0100
commitd944b27df121e2ee854a6c2fad13d6c6300792d4 (patch)
tree0af8ad5ef21263aad1df5db0c60c19a8bd70f5c2
parent692b65c84f0bb0ca70c11e62c865cbaf7e8e3afd (diff)
downloadlinux-sh-d944b27df121e2ee854a6c2fad13d6c6300792d4.tar.gz
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: 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>
-rw-r--r--drivers/i2c/busses/i2c-nvidia-gpu.c20
1 files changed, 8 insertions, 12 deletions
diff --git a/drivers/i2c/busses/i2c-nvidia-gpu.c b/drivers/i2c/busses/i2c-nvidia-gpu.c
index 62e18b4db0ed..f5d25ce00f03 100644
--- 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 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));
-
- if (time_is_before_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 (ret) {
dev_err(i2cd->dev, "i2c timeout error %x\n", val);
return -ETIMEDOUT;
}