Re: i8042 error at booting an Intel Cherry Trail-based device

[Takashi Iwai]

On Mon, 28 Nov 2016 14:56:36 +0100,
Takashi Iwai wrote:
> 
> Hi Dmitry,
> 
> I've been testing a small machine with Intel Cherry Trail chipset, and
> noticed that the kernel spews errors always like:
> 
>  i8042: PNP: No PS/2 controller found. Probing ports directly.
>  i8042: Can't read CTR while initializing i8042
>  i8042: probe of i8042 failed with error -5
> 
> Especially the second one ("Can't read CTR...") is annoying since it's
> in KERN_ERR level and thus appears even booted with quiet boot
> option.  Actually this is the only error message appearing at boot, so
> I'd love to get rid of it.
> 
> What is the preferred way to reduce this?  For example, is a patch
> like below OK to simply change the log level and the error code?

Any suggestion?

Adding Jiri to Cc, as he had a similar issue in the past.


thanks,

Takashi

> 
> 
> thanks,
> 
> Takashi
> 
> -- 8< --
> From: Takashi Iwai <tiwai@xxxxxxx>
> Subject: [PATCH] i8042: Reduce the log level of i8042 CTR read error
> 
> The error message "Can't read CTR while initializing i8042" appears on
> Cherry Trail-based devices at each boot time:
> 
>   i8042: PNP: No PS/2 controller found. Probing ports directly.
>   i8042: Can't read CTR while initializing i8042
>   i8042: probe of i8042 failed with error -5
> 
> This is annoying, since it's the only error message with KERN_ERR
> level appearing during the boot.
> 
> This patch changes the kernel log level to KERN_INFO for that message,
> and replaces the error code to -ENODEV so that this probe failure
> won't be complained like the above.
> 
> Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
> ---
>  drivers/input/serio/i8042.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c
> index b4e1ac5c9ea8..2c2683e357e9 100644
> --- a/drivers/input/serio/i8042.c
> +++ b/drivers/input/serio/i8042.c
> @@ -980,8 +980,8 @@ static int i8042_controller_init(void)
>  			udelay(50);
>  
>  		if (i8042_command(&ctr[n++ % 2], I8042_CMD_CTL_RCTR)) {
> -			pr_err("Can't read CTR while initializing i8042\n");
> -			return -EIO;
> +			pr_info("Can't read CTR while initializing i8042\n");
> +			return -ENODEV;
>  		}
>  
>  	} while (n < 2 || ctr[0] != ctr[1]);
> -- 
> 2.10.2
>