From: Emil Velikov <emil.l.velikov@gmail•com>
To: Laurent Pinchart <laurent.pinchart@ideasonboard•com>
Cc: Neil Armstrong <narmstrong@baylibre•com>,
David Airlie <airlied@linux•ie>,
dri-devel@lists•freedesktop.org,
Thierry Reding <thierry.reding@gmail•com>,
Sam Ravnborg <sam@ravnborg•org>, Marek Vasut <marex@denx•de>,
linux-samsung-soc@vger•kernel.org, Sean Paul <sean@poorly•run>,
Allison Randal <allison@lohutok•net>,
Krzysztof Kozlowski <krzk@kernel•org>,
Jonathan Hunter <jonathanh@nvidia•com>,
Maxime Ripard <maxime.ripard@bootlin•com>,
Kukjin Kim <kgene@kernel•org>, NXP Linux Team <linux-imx@nxp•com>,
Jonas Karlman <jonas@kwiboo•se>,
Alison Wang <alison.wang@nxp•com>,
Gwan-gyeong Mun <gwan-gyeong.mun@intel•com>,
Alexios Zavras <alexios.zavras@intel•com>,
Laurent Pinchart <laurent.pinchart+renesas@ideasonboard•com>,
linux-tegra@vger•kernel.org, Thomas Gleixner <tglx@linutronix•de>,
Vincent Abriou <vincent.abriou@st•com>,
linux-arm-kernel@lists•infradead.org,
Jernej Skrabec <jernej.skrabec@siol•net>,
Enrico Weigelt <info@metux•net>,
Seung-Woo Kim <sw0312.kim@samsung•com>,
Kyungmin Park <kyungmin.park@samsung•com>,
Pengutronix Kernel Team <kernel@pengutronix•de>,
Shawn Guo <shawnguo@kernel•org>
Subject: Re: [PATCH v1 14/16] drm/panel: call prepare/enable only once
Date: Mon, 5 Aug 2019 14:15:55 +0100 [thread overview]
Message-ID: <20190805131555.GA5005@arch-x1c3> (raw)
In-Reply-To: <20190805105928.GI29747@pendragon.ideasonboard.com>
On 2019/08/05, Laurent Pinchart wrote:
> Hi Sam,
>
> Thank you for the patch.
>
> On Sun, Aug 04, 2019 at 10:16:35PM +0200, Sam Ravnborg wrote:
> > Many panel drivers duplicate logic to prevent prepare to be called
> > for a panel that is already prepared.
> > Likewise for enable.
> >
> > Implement this logic in drm_panel so the individual drivers
> > no longer needs this.
> > A panel is considered prepared/enabled only if the prepare/enable call
> > succeeds.
> > For disable/unprepare it is unconditionally considered
> > disabled/unprepared.
> >
> > This allows calls to prepare/enable again, even if there were
> > some issue disabling a regulator or similar during disable/unprepare.
>
> Is this the right place to handle this ? Shouldn't the upper layers
> ensure than enable/disable and prepare/unprepare are correcty balanced,
> and not called multiple times ? Adding enabled and prepared state to
> drm_panel not only doesn't align well with atomic state handling, but
> also would hide issues in upper layers that should really be fixed
> there.
>
Fully agreed. Mistakes happen - hiding them, by returning "success" does
not sound like a wise approach.
HTH
Emil
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next prev parent reply other threads:[~2019-08-05 13:16 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-04 20:16 [PATCH v1 0/16] drm: panel related updates Sam Ravnborg
2019-08-04 20:16 ` [PATCH v1 01/16] drm/bridge: tc358767: fix opencoded use of drm_panel_* Sam Ravnborg
2019-08-05 9:35 ` Philipp Zabel
2019-08-05 11:53 ` Sam Ravnborg
2019-08-04 20:16 ` [PATCH v1 02/16] drm/exynos: " Sam Ravnborg
2019-12-01 11:32 ` Sam Ravnborg
2019-08-04 20:16 ` [PATCH v1 03/16] " Sam Ravnborg
2019-12-01 11:32 ` Sam Ravnborg
2019-08-04 20:16 ` [PATCH v1 04/16] drm/imx: " Sam Ravnborg
2019-08-05 9:34 ` Philipp Zabel
2019-08-04 20:16 ` [PATCH v1 05/16] drm/fsl-dcu: " Sam Ravnborg
2019-08-05 9:16 ` Stefan Agner
2019-08-05 11:54 ` Sam Ravnborg
2019-08-04 20:16 ` [PATCH v1 06/16] drm/msm: " Sam Ravnborg
2019-12-01 11:33 ` Sam Ravnborg
2019-08-04 20:16 ` [PATCH v1 07/16] drm/mxsfb: " Sam Ravnborg
2019-08-05 9:20 ` Stefan Agner
2019-08-04 20:16 ` [PATCH v1 08/16] drm/sti: " Sam Ravnborg
2019-08-07 11:55 ` Benjamin Gaignard
2019-08-04 20:16 ` [PATCH v1 09/16] drm/tegra: " Sam Ravnborg
2019-12-01 11:33 ` Sam Ravnborg
2019-08-04 20:16 ` [PATCH v1 10/16] drm/panel: ili9322: move bus_flags to get_modes() Sam Ravnborg
2019-08-06 12:56 ` Linus Walleij
2019-08-04 20:16 ` [PATCH v1 11/16] drm/panel: move drm_panel functions to .c file Sam Ravnborg
2019-08-05 10:45 ` Laurent Pinchart
2019-08-04 20:16 ` [PATCH v1 12/16] drm/panel: use inline comments in drm_panel.h Sam Ravnborg
2019-08-05 10:54 ` Laurent Pinchart
2019-08-04 20:16 ` [PATCH v1 13/16] drm/panel: drop return code from drm_panel_detach() Sam Ravnborg
2019-08-05 10:56 ` Laurent Pinchart
2019-08-04 20:16 ` [PATCH v1 14/16] drm/panel: call prepare/enable only once Sam Ravnborg
2019-08-05 10:59 ` Laurent Pinchart
2019-08-05 13:15 ` Emil Velikov [this message]
2019-08-05 16:51 ` Sam Ravnborg
2019-12-02 15:22 ` Laurent Pinchart
2019-08-05 17:01 ` Sean Paul
2019-12-02 15:15 ` Laurent Pinchart
2019-08-04 20:16 ` [PATCH v1 15/16] drm/panel: add backlight support Sam Ravnborg
2019-08-05 11:04 ` Laurent Pinchart
2019-08-04 20:16 ` [PATCH v1 16/16] drm/panel: simple: use drm_panel infrastructure Sam Ravnborg
2019-08-05 11:12 ` Laurent Pinchart
2019-08-05 13:18 ` [PATCH v1 0/16] drm: panel related updates Emil Velikov
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