From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756405AbeDYTmT (ORCPT ); Wed, 25 Apr 2018 15:42:19 -0400 Received: from mail-qk0-f195.google.com ([209.85.220.195]:35615 "EHLO mail-qk0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751296AbeDYTmR (ORCPT ); Wed, 25 Apr 2018 15:42:17 -0400 X-Google-Smtp-Source: AB8JxZrhPsErDTUtZk0XbXWCwBYlH2RhL3UCbz/6ceEkYAT/SAd3U6lpLUSgb6TcuZ3Jz4UBjPYTxw== From: "Jingoo Han" To: "'Daniel Vetter'" , "'DRI Development'" , "'LKML'" Cc: "'Lee Jones'" , "'Daniel Thompson'" , "'Meghana Madhyastha'" , "'Daniel Vetter'" References: <20180425174253.4616-1-daniel.vetter@ffwll.ch> In-Reply-To: <20180425174253.4616-1-daniel.vetter@ffwll.ch> Subject: Re: [PATCH 1/6] backlight: Nuke unused backlight.props.state states Date: Wed, 25 Apr 2018 15:42:15 -0400 Message-ID: <000001d3dccd$83e2c680$8ba85380$@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Outlook 16.0 Content-language: en-us Thread-Index: AQKYOvWw68i4qsBoV9wH2Dzil6RYcqKJJL1w Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday, April 25, 2018 1:43 PM, Daniel Vetter wrote: > > The backlight power state handling is supremely confusing. We have: > - props.power, using FB_BLANK_* defines > - props.fb_blank, using the same, but deprecated int favour of > props.state > - props.state, using the BL_CORE_* defines > - and finally a bunch of backlight drivers treat brightness == 0 as > off. But of course not all of them. > > This is way too much confusion to fix in a simple patch, but at least > prevent more hilarity from spreading by removing the unused BL_CORE_* > defines. I have no idea why exactly anyone would need that. > > Wrt the ideal state, we really just want a boolean state. The 4 power > saving states that the fbdev subsystem uses are overkill in todays hw > (this was only relevant for VGA and similar analog circuits like > TV-out), the new drm atomic modeset api simplified even the uapi to a > simple bool. And there was never a valid technical reason to have the > intermediate fbdev power states for backlights (those really only can > be either off or on). > > Cleanup motivated by Meghana's questions about all this. > > Cc: Lee Jones > Cc: Daniel Thompson > Cc: Jingoo Han > Cc: Meghana Madhyastha > Acked-by: Daniel Thompson > Signed-off-by: Daniel Vetter Acked-by: Jingoo Han I really love this patch! Good job! Thank you. Best regards, Jingoo Han > --- > include/linux/backlight.h | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/include/linux/backlight.h b/include/linux/backlight.h > index 2baab6f3861d..1db67662bfcb 100644 > --- a/include/linux/backlight.h > +++ b/include/linux/backlight.h > @@ -84,9 +84,6 @@ struct backlight_properties { > > #define BL_CORE_SUSPENDED (1 << 0) /* backlight is suspended */ > #define BL_CORE_FBBLANK (1 << 1) /* backlight is under an fb > blank event */ > -#define BL_CORE_DRIVER4 (1 << 28) /* reserved for driver > specific use */ > -#define BL_CORE_DRIVER3 (1 << 29) /* reserved for driver > specific use */ > -#define BL_CORE_DRIVER2 (1 << 30) /* reserved for driver > specific use */ > #define BL_CORE_DRIVER1 (1 << 31) /* reserved for driver > specific use */ > > }; > -- > 2.17.0