[SRU][B/E/F/U/OEM-B][PATCH v2 1/1] UBUNTU: SAUCE: Input: i8042 - fix the selftest retry logic

[Stefan Bader]

On 16.03.20 10:27, You-Sheng Yang wrote:
> BugLink: https://bugs.launchpad.net/bugs/1866734
> 
> It returns -NODEV at the first selftest timeout, so the retry logic
> doesn't work. Move the return outside of the while loop to make it real
> retry 5 times before returns -ENODEV.
> 
> BTW, the origin loop will retry 6 times, also fix this.
> 
> Signed-off-by: You-Sheng Yang <vicamo.yang at canonical.com>
> (backported from
> https://lore.kernel.org/linux-input/20200310033640.14440-1-vicamo@gmail.com/)
> ---

The subject appears as this should go into Bionic main kernel, too. However the
bug report has no nomination for the Bionic main kernel. Which is correct?

-Stefan

>  drivers/input/serio/i8042.c | 23 +++++++++++++----------
>  1 file changed, 13 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c
> index 7f4592177607..cc079c5680d6 100644
> --- a/drivers/input/serio/i8042.c
> +++ b/drivers/input/serio/i8042.c
> @@ -927,25 +927,28 @@ static int i8042_controller_selftest(void)
>  {
>  	unsigned char param;
>  	int i = 0;
> +	int ret;
>  
>  	/*
>  	 * We try this 5 times; on some really fragile systems this does not
>  	 * take the first time...
>  	 */
> -	do {
> -
> -		if (i8042_command(&param, I8042_CMD_CTL_TEST)) {
> -			pr_info("i8042 controller selftest timeout\n");
> -			return -ENODEV;
> -		}
> +	while (i++ < 5) {
>  
> -		if (param == I8042_RET_CTL_TEST)
> +		ret = i8042_command(&param, I8042_CMD_CTL_TEST);
> +		if (ret)
> +			pr_info("i8042 controller selftest timeout (%d/5)\n", i);
> +		else if (param == I8042_RET_CTL_TEST)
>  			return 0;
> +		else
> +			dbg("i8042 controller selftest: %#x != %#x\n",
> +			    param, I8042_RET_CTL_TEST);
>  
> -		dbg("i8042 controller selftest: %#x != %#x\n",
> -		    param, I8042_RET_CTL_TEST);
>  		msleep(50);
> -	} while (i++ < 5);
> +	}
> +
> +	if (ret)
> +		return -ENODEV;
>  
>  #ifdef CONFIG_X86
>  	/*
>