linux-kernel - Re: [PATCH 2/3] thinkpad_acpi: Don't repeat ourselves in hotkey_init_tablet

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Date:   Tue, 8 Nov 2016 09:08:47 -0200
From:   Henrique de Moraes Holschuh <hmh@....eng.br>
To:     Lyude <lyude@...hat.com>
Cc:     ibm-acpi-devel@...ts.sourceforge.net,
        Daniel Martin <consume.noise@...il.com>,
        Darren Hart <dvhart@...radead.org>,
        platform-driver-x86@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/3] thinkpad_acpi: Don't repeat ourselves in
 hotkey_init_tablet_mode()

On Mon, 07 Nov 2016, Lyude wrote:
> There's no need to have multiple copies of the logic we use for checking
> whether or not we're in tablet mode, so just use
> hotkey_get_tablet_mode() when checking the initial state in
> hotkey_init_tablet_mode().

...

> @@ -3130,13 +3130,16 @@ hotkey_init_tablet_mode(void)
>  	/* For X41t, X60t, X61t Tablets... */
>  	if (acpi_evalf(hkey_handle, &res, "MHKG", "qd")) {
>  		tp_features.hotkey_tablet = TP_HOTKEY_TABLET_USES_MHKG;
> -		in_tablet_mode = !!(res & TP_HOTKEY_TABLET_MASK);
>  		type = "MHKG";
>  	}
>  
>  	if (!tp_features.hotkey_tablet)
>  		return 0;
>  
> +	res = hotkey_get_tablet_mode(&in_tablet_mode);
> +	if (res)
> +		return res;
> +

Won't this way of doing things cause the ACPI methods to be called
twice in a row?

The hotkey_init_tablet_mode() code does mode detection, and thus
hotkey_get_tablet_mode() must be kept in sync with it *anyway* (and not
the opposite), so it doesn't look like a very relevant maintenance
burden...

-- 
  Henrique Holschuh