From: Sean Paul <seanpaul@chromium.org>
To: Douglas Anderson <dianders@chromium.org>
Cc: Andrzej Hajda <a.hajda@samsung.com>,
Neil Armstrong <narmstrong@baylibre.com>,
Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
Jonas Karlman <jonas@kwiboo.se>,
Jernej Skrabec <jernej.skrabec@siol.net>,
Sam Ravnborg <sam@ravnborg.org>, Wolfram Sang <wsa@kernel.org>,
robdclark@chromium.org,
dri-devel <dri-devel@lists.freedesktop.org>,
David Airlie <airlied@linux.ie>,
linux-arm-msm <linux-arm-msm@vger.kernel.org>,
Steev Klimaszewski <steev@kali.org>,
Stephen Boyd <swboyd@chromium.org>,
Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>,
Thierry Reding <thierry.reding@gmail.com>,
linux-i2c@vger.kernel.org,
Bjorn Andersson <bjorn.andersson@linaro.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v5 10/20] drm/panel: panel-simple: Get rid of hacky HPD chicken-and-egg code
Date: Wed, 28 Apr 2021 12:35:09 -0400 [thread overview]
Message-ID: <CAOw6vbJj327Y0vtzwm=aOqwyHScE5XYG2LDw6TxCh_N+rCJ9kQ@mail.gmail.com> (raw)
In-Reply-To: <20210423095743.v5.10.I40eeedc23459d1e3fc96fa6cdad775d88c6e706c@changeid>
On Fri, Apr 23, 2021 at 1:00 PM Douglas Anderson <dianders@chromium.org> wrote:
>
> When I added support for the hpd-gpio to simple-panel in commit
> 48834e6084f1 ("drm/panel-simple: Support hpd-gpios for delaying
> prepare()"), I added a special case to handle a circular dependency I
> was running into on the ti-sn65dsi86 bridge chip. On my board the
> hpd-gpio is actually provided by the bridge chip. That was causing
> some circular dependency problems that I had to work around by getting
> the hpd-gpio late.
>
> I've now reorganized the ti-sn65dsi86 bridge chip driver to be a
> collection of sub-drivers. Now the GPIO part can probe separately and
> that breaks the chain. Let's get rid of the old code to clean things
> up.
>
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
> ---
>
> (no changes since v1)
>
> drivers/gpu/drm/panel/panel-simple.c | 24 +++++-------------------
> 1 file changed, 5 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
> index 9746eda6f675..bd208abcbf07 100644
> --- a/drivers/gpu/drm/panel/panel-simple.c
> +++ b/drivers/gpu/drm/panel/panel-simple.c
> @@ -366,8 +366,7 @@ static int panel_simple_unprepare(struct drm_panel *panel)
> return 0;
> }
>
> -static int panel_simple_get_hpd_gpio(struct device *dev,
> - struct panel_simple *p, bool from_probe)
> +static int panel_simple_get_hpd_gpio(struct device *dev, struct panel_simple *p)
> {
> int err;
>
> @@ -375,17 +374,10 @@ static int panel_simple_get_hpd_gpio(struct device *dev,
> if (IS_ERR(p->hpd_gpio)) {
> err = PTR_ERR(p->hpd_gpio);
>
> - /*
> - * If we're called from probe we won't consider '-EPROBE_DEFER'
> - * to be an error--we'll leave the error code in "hpd_gpio".
> - * When we try to use it we'll try again. This allows for
> - * circular dependencies where the component providing the
> - * hpd gpio needs the panel to init before probing.
> - */
> - if (err != -EPROBE_DEFER || !from_probe) {
> + if (err != -EPROBE_DEFER)
> dev_err(dev, "failed to get 'hpd' GPIO: %d\n", err);
> - return err;
> - }
> +
> + return err;
> }
>
> return 0;
> @@ -416,12 +408,6 @@ static int panel_simple_prepare_once(struct panel_simple *p)
> msleep(delay);
>
> if (p->hpd_gpio) {
> - if (IS_ERR(p->hpd_gpio)) {
> - err = panel_simple_get_hpd_gpio(dev, p, false);
> - if (err)
> - goto error;
> - }
> -
> if (p->desc->delay.hpd_absent_delay)
> hpd_wait_us = p->desc->delay.hpd_absent_delay * 1000UL;
> else
> @@ -682,7 +668,7 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
>
> panel->no_hpd = of_property_read_bool(dev->of_node, "no-hpd");
> if (!panel->no_hpd) {
> - err = panel_simple_get_hpd_gpio(dev, panel, true);
> + err = panel_simple_get_hpd_gpio(dev, panel);
> if (err)
> return err;
> }
> --
> 2.31.1.498.g6c1eba8ee3d-goog
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
next prev parent reply other threads:[~2021-04-28 16:35 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-23 16:58 [PATCH v5 00/20] drm: Fix EDID reading on ti-sn65dsi86; solve some chicken-and-egg problems Douglas Anderson
2021-04-23 16:58 ` [PATCH v5 01/20] drm/panel: panel-simple: Add missing pm_runtime_disable() calls Douglas Anderson
2021-04-28 16:32 ` Sean Paul
2021-04-30 0:58 ` Linus Walleij
2021-04-30 1:24 ` Doug Anderson
2021-04-30 1:27 ` Linus Walleij
2021-04-30 21:04 ` Doug Anderson
2021-05-01 12:07 ` Linus Walleij
2021-05-03 20:41 ` Doug Anderson
2021-05-05 12:51 ` Linus Walleij
2021-04-23 16:58 ` [PATCH v5 02/20] drm/bridge: ti-sn65dsi86: Rename the main driver data structure Douglas Anderson
2021-04-23 16:58 ` [PATCH v5 03/20] drm/bridge: ti-sn65dsi86: More renames in prep for sub-devices Douglas Anderson
2021-04-23 16:58 ` [PATCH v5 04/20] drm/bridge: ti-sn65dsi86: Use devm to do our runtime_disable Douglas Anderson
2021-04-23 16:58 ` [PATCH v5 05/20] drm/bridge: ti-sn65dsi86: Clean debugfs code Douglas Anderson
2021-04-23 16:58 ` [PATCH v5 06/20] drm/bridge: ti-sn65dsi86: Add local var for "dev" to simplify probe Douglas Anderson
2021-04-23 16:58 ` [PATCH v5 07/20] drm/bridge: ti-sn65dsi86: Cleanup managing of drvdata Douglas Anderson
2021-04-23 16:58 ` [PATCH v5 08/20] drm/bridge: ti-sn65dsi86: Move all the chip-related init to the start Douglas Anderson
2021-04-23 16:58 ` [PATCH v5 09/20] drm/bridge: ti-sn65dsi86: Break GPIO and MIPI-to-eDP bridge into sub-drivers Douglas Anderson
2021-05-01 11:59 ` Linus Walleij
2021-05-03 16:55 ` Doug Anderson
2021-04-23 16:58 ` [PATCH v5 10/20] drm/panel: panel-simple: Get rid of hacky HPD chicken-and-egg code Douglas Anderson
2021-04-28 16:35 ` Sean Paul [this message]
2021-04-23 16:58 ` [PATCH v5 11/20] drm/bridge: ti-sn65dsi86: Use pm_runtime autosuspend Douglas Anderson
2021-04-23 16:58 ` [PATCH v5 12/20] drm/bridge: ti-sn65dsi86: Code motion of refclk management functions Douglas Anderson
2021-04-23 16:58 ` [PATCH v5 13/20] drm/bridge: ti-sn65dsi86: If refclk, DP AUX can happen w/out pre-enable Douglas Anderson
2021-04-23 16:59 ` [PATCH v5 14/20] drm/bridge: ti-sn65dsi86: Promote the AUX channel to its own sub-dev Douglas Anderson
2021-05-03 20:27 ` Doug Anderson
2021-04-23 16:59 ` [PATCH v5 15/20] i2c: i2c-core-of: Fix corner case of finding adapter by node Douglas Anderson
2021-04-23 16:59 ` [PATCH v5 16/20] drm/panel: panel-simple: Remove extra call: drm_connector_update_edid_property() Douglas Anderson
2021-04-28 16:38 ` Sean Paul
2021-04-23 16:59 ` [PATCH v5 17/20] drm/panel: panel-simple: Power the panel when reading the EDID Douglas Anderson
2021-04-28 16:44 ` Sean Paul
2021-04-23 16:59 ` [PATCH v5 18/20] drm/panel: panel-simple: Cache the EDID as long as we retain power Douglas Anderson
2021-04-28 16:50 ` Sean Paul
2021-04-23 16:59 ` [PATCH v5 19/20] drm/bridge: ti-sn65dsi86: Don't read EDID blob over DDC Douglas Anderson
2021-04-23 16:59 ` [PATCH v5 20/20] arm64: dts: qcom: Link the panel to the bridge's DDC bus Douglas Anderson
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