RE: [PATCH v3] i2c: nvidia-gpu: Handle timeout correctly in gpu_i2c_check_status()

From: Ajay Gupta
Date: Tue Mar 24 2020 - 17:16:56 EST


Hi Wolfram,

> -----Original Message-----
> From: Wolfram Sang <wsa@xxxxxxxxxxxxx>
> Sent: Tuesday, March 24, 2020 1:58 PM
> To: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
> Cc: Ajay Gupta <ajayg@xxxxxxxxxx>; Andy Shevchenko
> <andriy.shevchenko@xxxxxxxxxxxxxxx>; open list:I2C CONTROLLER DRIVER
> FOR NVIDIA GPU <linux-i2c@xxxxxxxxxxxxxxx>; open list <linux-
> kernel@xxxxxxxxxxxxxxx>
> Subject: Re: [PATCH v3] i2c: nvidia-gpu: Handle timeout correctly in
> gpu_i2c_check_status()
>
> On Tue, Mar 24, 2020 at 11:28:11PM +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.
> >
> > 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@xxxxxxxxxxxxxxx>
> > Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
>
> Looks good to me, thanks Andy for the suggestion!
>
> Waiting for the Rev-by from Ajay (driver maintainer).
Reviewed-by: Ajay Gupta <ajayg@xxxxxxxxxx>
Tested-by: Ajay Gupta <ajayg@xxxxxxxxxx>

Thanks
Ajay
> nvpublic