Hi Andy,
> On Mar 24, 2020, at 21:41, Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
>
> On Tue, Mar 24, 2020 at 09:07:12PM +0800, Kai-Heng Feng wrote:
>> 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.
>
> Thank you for an update, my comments below.
>
>> 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) {
>
> Bad formatting. But see below.
>
>> + 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;
>> }
>
>
> Overall it can use simple tries since you already have sleep inside, but
> moreover, you may simple switch to readl_poll_timeout() this entire
> loop.
Yes that can make the retry loop much simpler.
I'll send a v3 based on your suggestion.
Kai-Heng
>
> --
> With Best Regards,
> Andy Shevchenko
>
>
