From: Tomi Valkeinen <tomi.valkeinen@ti.com>
To: Sebastian Reichel <sre@kernel.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
Nikhil Devshatwar <nikhil.nd@ti.com>,
<dri-devel@lists.freedesktop.org>,
Tony Lindgren <tony@atomide.com>, <hns@goldelico.com>,
Sekhar Nori <nsekhar@ti.com>, <linux-omap@vger.kernel.org>,
Sam Ravnborg <sam@ravnborg.org>
Subject: Re: [PATCH v5 27/29] drm/omap: dsi: remove ulps support
Date: Mon, 14 Dec 2020 20:55:36 +0200 [thread overview]
Message-ID: <0484822c-40e1-6738-aea8-c4a5d6609bb1@ti.com> (raw)
In-Reply-To: <20201214173923.2plaloeowhxddbwe@earth.universe>
On 14/12/2020 19:39, Sebastian Reichel wrote:
> Hi,
>
> On Tue, Dec 08, 2020 at 02:28:53PM +0200, Tomi Valkeinen wrote:
>> ULPS doesn't work, and I have been unable to get it to work. As ULPS
>> is a minor power-saving feature which requires substantial amount of
>> non-trivial code, and we have trouble just getting and
>> keeping DSI working at all, remove ULPS support.
>>
>> When the DSI driver works reliably for command and video mode displays,
>> someone interested can add it back.
>>
>> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
>> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>> ---
>
> Is it really 'minor power-saving'? If I search for DSI and ULPS among
> the first results is a TI datasheet for SN65DSI84, which claims device
> active current in the more than 100mA range and ULPS current in the
> less than 10mA range.
I don't have any numbers, just my guesses. For videomode displays or command mode displays in active
use, I don't think ULPS matters much. The link is mostly not in ULPS. And if the display is blanked,
things are off, so again not in ULPS.
It's only for command mode displays, when updated rarely, where I think ULPS matters. Which, of
course, is probably not unusual use case if you have a cmdmode display. But whether OMAP DSI power
savings matches SN65DSI84, I have no clue.
> Considering all known omapdrm DSI users are battery powered devices
> caring for saving as much power as possible, it might be good to just
> keep this until it is being fixed considering this is very close to
> the end of the series anyways?
I don't like to leave known to be broken code around, unless someone has plans to work on it. I
wouldn't be surprised to see ULPS still broken two years from now =). It should be trivial to add
the relevant bits back later.
But I can leave it here if you think it's better, presuming it doesn't have bigger conflicts with
the 29/29 or break anything. However, I have only a few days left in TI, which is why I'm rushing
here a bit (*). If I hit problems, I either have to drop the whole series, or push it in its current
form.
Tomi
(*) But I will fix possible issues caused by my push, of course.
--
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
WARNING: multiple messages have this Message-ID (diff)
From: Tomi Valkeinen <tomi.valkeinen@ti.com>
To: Sebastian Reichel <sre@kernel.org>
Cc: Tony Lindgren <tony@atomide.com>,
hns@goldelico.com, Sekhar Nori <nsekhar@ti.com>,
dri-devel@lists.freedesktop.org,
Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
linux-omap@vger.kernel.org, Sam Ravnborg <sam@ravnborg.org>,
Nikhil Devshatwar <nikhil.nd@ti.com>
Subject: Re: [PATCH v5 27/29] drm/omap: dsi: remove ulps support
Date: Mon, 14 Dec 2020 20:55:36 +0200 [thread overview]
Message-ID: <0484822c-40e1-6738-aea8-c4a5d6609bb1@ti.com> (raw)
In-Reply-To: <20201214173923.2plaloeowhxddbwe@earth.universe>
On 14/12/2020 19:39, Sebastian Reichel wrote:
> Hi,
>
> On Tue, Dec 08, 2020 at 02:28:53PM +0200, Tomi Valkeinen wrote:
>> ULPS doesn't work, and I have been unable to get it to work. As ULPS
>> is a minor power-saving feature which requires substantial amount of
>> non-trivial code, and we have trouble just getting and
>> keeping DSI working at all, remove ULPS support.
>>
>> When the DSI driver works reliably for command and video mode displays,
>> someone interested can add it back.
>>
>> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
>> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>> ---
>
> Is it really 'minor power-saving'? If I search for DSI and ULPS among
> the first results is a TI datasheet for SN65DSI84, which claims device
> active current in the more than 100mA range and ULPS current in the
> less than 10mA range.
I don't have any numbers, just my guesses. For videomode displays or command mode displays in active
use, I don't think ULPS matters much. The link is mostly not in ULPS. And if the display is blanked,
things are off, so again not in ULPS.
It's only for command mode displays, when updated rarely, where I think ULPS matters. Which, of
course, is probably not unusual use case if you have a cmdmode display. But whether OMAP DSI power
savings matches SN65DSI84, I have no clue.
> Considering all known omapdrm DSI users are battery powered devices
> caring for saving as much power as possible, it might be good to just
> keep this until it is being fixed considering this is very close to
> the end of the series anyways?
I don't like to leave known to be broken code around, unless someone has plans to work on it. I
wouldn't be surprised to see ULPS still broken two years from now =). It should be trivial to add
the relevant bits back later.
But I can leave it here if you think it's better, presuming it doesn't have bigger conflicts with
the 29/29 or break anything. However, I have only a few days left in TI, which is why I'm rushing
here a bit (*). If I hit problems, I either have to drop the whole series, or push it in its current
form.
Tomi
(*) But I will fix possible issues caused by my push, of course.
--
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
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next prev parent reply other threads:[~2020-12-14 18:58 UTC|newest]
Thread overview: 144+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-08 12:28 [PATCH v5 00/29] Convert DSI code to use drm_mipi_dsi and drm_panel (second half) Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-08 12:28 ` [PATCH v5 01/29] drm/panel: panel-dsi-cm: cleanup tear enable Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-14 13:09 ` Sebastian Reichel
2020-12-14 13:09 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 02/29] ARM: dts: omap5: add address-cells & size-cells to dsi Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-14 13:09 ` Sebastian Reichel
2020-12-14 13:09 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 03/29] drm/omap: pll: fix iteration loop check Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-14 13:10 ` Sebastian Reichel
2020-12-14 13:10 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 04/29] drm/omap: dsi: set trans_mode according to client mode_flags Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-14 13:10 ` Sebastian Reichel
2020-12-14 13:10 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 05/29] drm/panel: panel-dsi-cm: set column & page at setup Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-14 13:10 ` Sebastian Reichel
2020-12-14 13:10 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 06/29] drm/omap: dsi: send nop instead of page & column Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-14 14:22 ` Sebastian Reichel
2020-12-14 14:22 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 07/29] drm/omap: dsi: simplify VC handling Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-14 14:31 ` Sebastian Reichel
2020-12-14 14:31 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 08/29] drm/omap: dsi: drop useless channel checks Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-14 14:32 ` Sebastian Reichel
2020-12-14 14:32 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 09/29] drm/omap: dsi: cleanup dispc channel usage Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-08 15:17 ` Laurent Pinchart
2020-12-08 15:17 ` Laurent Pinchart
2020-12-14 14:35 ` Sebastian Reichel
2020-12-14 14:35 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 10/29] drm/omap: dsi: rename 'channel' to 'vc' Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-08 15:22 ` Laurent Pinchart
2020-12-08 15:22 ` Laurent Pinchart
2020-12-14 15:18 ` Sebastian Reichel
2020-12-14 15:18 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 11/29] drm/omap: dsi: pass vc to various functions Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-08 15:38 ` Laurent Pinchart
2020-12-08 15:38 ` Laurent Pinchart
2020-12-08 15:45 ` Tomi Valkeinen
2020-12-08 15:45 ` Tomi Valkeinen
2020-12-14 15:37 ` Sebastian Reichel
2020-12-14 15:37 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 12/29] drm/omap: dsi: untangle vc & channel Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-08 15:41 ` Laurent Pinchart
2020-12-08 15:41 ` Laurent Pinchart
2020-12-14 15:47 ` Sebastian Reichel
2020-12-14 15:47 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 13/29] drm/omap: dsi: skip dsi_vc_enable_hs when already in correct mode Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-14 15:50 ` Sebastian Reichel
2020-12-14 15:50 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 14/29] drm/omap: dsi: enable HS before sending the frame Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-08 15:42 ` Laurent Pinchart
2020-12-08 15:42 ` Laurent Pinchart
2020-12-14 15:51 ` Sebastian Reichel
2020-12-14 15:51 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 15/29] drm/omap: dsi: use separate VCs for cmd and video Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-14 15:54 ` Sebastian Reichel
2020-12-14 15:54 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 16/29] drm/panel: panel-dsi-cm: remove extra 'if' Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-08 15:42 ` Laurent Pinchart
2020-12-08 15:42 ` Laurent Pinchart
2020-12-14 15:55 ` Sebastian Reichel
2020-12-14 15:55 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 17/29] drm/panel: panel-dsi-cm: add panel database to driver Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-14 16:04 ` Sebastian Reichel
2020-12-14 16:04 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 18/29] drm/panel: panel-dsi-cm: drop unneeded includes Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-14 16:06 ` Sebastian Reichel
2020-12-14 16:06 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 19/29] drm/omap: dsi: move structs & defines to dsi.h Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-14 16:14 ` Sebastian Reichel
2020-12-14 16:14 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 20/29] drm/omap: dsi: move enable/disable to bridge enable/disable Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-14 16:16 ` Sebastian Reichel
2020-12-14 16:16 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 21/29] drm/omap: dsi: display_enable cleanup Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-14 16:17 ` Sebastian Reichel
2020-12-14 16:17 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 22/29] drm/omap: dsi: display_disable cleanup Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-14 16:20 ` Sebastian Reichel
2020-12-14 16:20 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 23/29] drm/omap: dsi: rename dsi_display_* functions Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-14 16:22 ` Sebastian Reichel
2020-12-14 16:22 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 24/29] drm/omap: dsi: cleanup initial vc setup Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-14 16:34 ` Sebastian Reichel
2020-12-14 16:34 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 25/29] drm/omap: dsi: split video mode enable/disable into separate func Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-14 16:38 ` Sebastian Reichel
2020-12-14 16:38 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 26/29] drm/omap: dsi: fix and cleanup ddr_clk_always_on Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-14 16:39 ` Sebastian Reichel
2020-12-14 16:39 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 27/29] drm/omap: dsi: remove ulps support Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-14 17:39 ` Sebastian Reichel
2020-12-14 17:39 ` Sebastian Reichel
2020-12-14 18:55 ` Tomi Valkeinen [this message]
2020-12-14 18:55 ` Tomi Valkeinen
2020-12-14 22:08 ` Sebastian Reichel
2020-12-14 22:08 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 28/29] drm/omap: dsi: fix DCS_CMD_ENABLE Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-14 16:48 ` Sebastian Reichel
2020-12-14 16:48 ` Sebastian Reichel
2020-12-08 12:28 ` [PATCH v5 29/29] drm/omap: dsi: allow DSI commands to be sent early Tomi Valkeinen
2020-12-08 12:28 ` Tomi Valkeinen
2020-12-08 15:48 ` Laurent Pinchart
2020-12-08 15:48 ` Laurent Pinchart
2020-12-10 7:34 ` Tomi Valkeinen
2020-12-10 7:34 ` Tomi Valkeinen
2020-12-10 8:17 ` Tomi Valkeinen
2020-12-10 8:17 ` Tomi Valkeinen
2020-12-14 17:17 ` Sebastian Reichel
2020-12-14 17:17 ` Sebastian Reichel
2020-12-15 10:05 ` Tomi Valkeinen
2020-12-15 10:05 ` Tomi Valkeinen
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