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From:   AceLan Kao <acelan.kao@canonical.com>
Date:   Tue, 17 Mar 2020 12:22:48 +0800
Message-ID: <CAFv23Q=q2N7gyvKrgJZJN04+1YqV=VxP2smm6gxn4oAwx2=QNA@mail.gmail.com>
Subject: Re: [PATCH v2] Input: i8042 - fix the selftest retry logic
To:     You-Sheng Yang <vicamo@gmail.com>
Cc:     Allison Randal <allison@lohutok.net>,
        Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        Enrico Weigelt <info@metux.net>, linux-input@vger.kernel.org,
        "Linux-Kernel@Vger. Kernel. Org" <linux-kernel@vger.kernel.org>,
        "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
        Stephen Boyd <swboyd@chromium.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        You-Sheng Yang <vicamo.yang@canonical.com>
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This v2 fix my issue, too.
Please consider to merge this patch.
Thanks.

You-Sheng Yang <vicamo@gmail.com> 於 2020年3月10日 週二 上午11:37寫道：
>
> From: You-Sheng Yang <vicamo.yang@canonical.com>
>
> 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@canonical.com>
> ---
>  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 20ff2bed3917..e8f2004071d4 100644
> --- a/drivers/input/serio/i8042.c
> +++ b/drivers/input/serio/i8042.c
> @@ -937,25 +937,28 @@ 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_err("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_err("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
>         /*
> --
> 2.25.0
>