From: Douglas Anderson <dianders@chromium.org> To: Thierry Reding <thierry.reding@gmail.com>, Sam Ravnborg <sam@ravnborg.org> Cc: Rob Clark <robdclark@chromium.org>, Stephen Boyd <swboyd@chromium.org>, Douglas Anderson <dianders@chromium.org>, Daniel Vetter <daniel@ffwll.ch>, David Airlie <airlied@linux.ie>, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 2/5] drm/panel-simple: Don't wait longer for HPD than hpd_absent_delay Date: Fri, 15 Jan 2021 14:44:17 -0800 [thread overview] Message-ID: <20210115144345.v2.2.I183b1817610d7a82fdd3bc852e96d2985df9623f@changeid> (raw) In-Reply-To: <20210115224420.1635017-1-dianders@chromium.org> If a panel has an hpd_absent_delay specified then we know exactly how long the maximum time is before HPD must be asserted. That means we can use it as a timeout for polling the HPD pin instead of using an arbitrary timeout. This is especially useful for dealing with panels that periodically fail to power on and need to be retried. We can detect the problem sooner. Signed-off-by: Douglas Anderson <dianders@chromium.org> --- Changes in v2: - ("drm/panel-simple: Don't wait longer for HPD...") new for v2. drivers/gpu/drm/panel/panel-simple.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c index 581ab6810b70..30842cf6d414 100644 --- a/drivers/gpu/drm/panel/panel-simple.c +++ b/drivers/gpu/drm/panel/panel-simple.c @@ -382,6 +382,7 @@ static int panel_simple_prepare(struct drm_panel *panel) unsigned int delay; int err; int hpd_asserted; + unsigned long hpd_wait_us; if (p->prepared_time != 0) return 0; @@ -409,9 +410,14 @@ static int panel_simple_prepare(struct drm_panel *panel) goto error; } + if (p->desc->delay.hpd_absent_delay) + hpd_wait_us = p->desc->delay.hpd_absent_delay * 1000UL; + else + hpd_wait_us = 2000000; + err = readx_poll_timeout(gpiod_get_value_cansleep, p->hpd_gpio, hpd_asserted, hpd_asserted, - 1000, 2000000); + 1000, hpd_wait_us); if (hpd_asserted < 0) err = hpd_asserted; -- 2.30.0.284.gd98b1dd5eaa7-goog
WARNING: multiple messages have this Message-ID (diff)
From: Douglas Anderson <dianders@chromium.org> To: Thierry Reding <thierry.reding@gmail.com>, Sam Ravnborg <sam@ravnborg.org> Cc: Rob Clark <robdclark@chromium.org>, David Airlie <airlied@linux.ie>, linux-kernel@vger.kernel.org, Douglas Anderson <dianders@chromium.org>, dri-devel@lists.freedesktop.org, Stephen Boyd <swboyd@chromium.org> Subject: [PATCH v2 2/5] drm/panel-simple: Don't wait longer for HPD than hpd_absent_delay Date: Fri, 15 Jan 2021 14:44:17 -0800 [thread overview] Message-ID: <20210115144345.v2.2.I183b1817610d7a82fdd3bc852e96d2985df9623f@changeid> (raw) In-Reply-To: <20210115224420.1635017-1-dianders@chromium.org> If a panel has an hpd_absent_delay specified then we know exactly how long the maximum time is before HPD must be asserted. That means we can use it as a timeout for polling the HPD pin instead of using an arbitrary timeout. This is especially useful for dealing with panels that periodically fail to power on and need to be retried. We can detect the problem sooner. Signed-off-by: Douglas Anderson <dianders@chromium.org> --- Changes in v2: - ("drm/panel-simple: Don't wait longer for HPD...") new for v2. drivers/gpu/drm/panel/panel-simple.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c index 581ab6810b70..30842cf6d414 100644 --- a/drivers/gpu/drm/panel/panel-simple.c +++ b/drivers/gpu/drm/panel/panel-simple.c @@ -382,6 +382,7 @@ static int panel_simple_prepare(struct drm_panel *panel) unsigned int delay; int err; int hpd_asserted; + unsigned long hpd_wait_us; if (p->prepared_time != 0) return 0; @@ -409,9 +410,14 @@ static int panel_simple_prepare(struct drm_panel *panel) goto error; } + if (p->desc->delay.hpd_absent_delay) + hpd_wait_us = p->desc->delay.hpd_absent_delay * 1000UL; + else + hpd_wait_us = 2000000; + err = readx_poll_timeout(gpiod_get_value_cansleep, p->hpd_gpio, hpd_asserted, hpd_asserted, - 1000, 2000000); + 1000, hpd_wait_us); if (hpd_asserted < 0) err = hpd_asserted; -- 2.30.0.284.gd98b1dd5eaa7-goog _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
next prev parent reply other threads:[~2021-01-15 22:45 UTC|newest] Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-01-15 22:44 [PATCH v2 0/5] drm/panel-simple: Patches for N116BCA-EA1 Douglas Anderson 2021-01-15 22:44 ` Douglas Anderson 2021-01-15 22:44 ` [PATCH v2 1/5] drm/panel-simple: Undo enable if HPD never asserts Douglas Anderson 2021-01-15 22:44 ` Douglas Anderson 2021-01-15 22:49 ` Stephen Boyd 2021-01-15 22:49 ` Stephen Boyd 2021-01-15 22:44 ` Douglas Anderson [this message] 2021-01-15 22:44 ` [PATCH v2 2/5] drm/panel-simple: Don't wait longer for HPD than hpd_absent_delay Douglas Anderson 2021-01-25 20:26 ` Stephen Boyd 2021-01-25 20:26 ` Stephen Boyd 2021-01-15 22:44 ` [PATCH v2 3/5] drm/panel-simple: Retry if we timeout waiting for HPD Douglas Anderson 2021-01-15 22:44 ` Douglas Anderson 2021-01-25 20:28 ` Stephen Boyd 2021-01-25 20:28 ` Stephen Boyd 2021-01-27 21:11 ` Doug Anderson 2021-01-27 21:11 ` Doug Anderson 2021-01-15 22:44 ` [PATCH v2 4/5] dt-bindings: dt-bindings: display: simple: Add N116BCA-EA1 Douglas Anderson 2021-01-15 22:44 ` Douglas Anderson 2021-01-15 22:59 ` Doug Anderson 2021-01-15 22:59 ` Doug Anderson 2021-01-25 20:29 ` Stephen Boyd 2021-01-25 20:29 ` Stephen Boyd 2021-02-08 21:50 ` Rob Herring 2021-02-08 21:50 ` Rob Herring 2021-01-15 22:44 ` [PATCH v2 5/5] drm/panel-simple: " Douglas Anderson 2021-01-15 22:44 ` Douglas Anderson 2021-01-25 20:29 ` Stephen Boyd 2021-01-25 20:29 ` Stephen Boyd 2021-03-05 15:42 ` [PATCH v2 0/5] drm/panel-simple: Patches for N116BCA-EA1 Doug Anderson 2021-03-05 15:42 ` Doug Anderson 2021-03-10 23:25 ` Linus Walleij 2021-03-10 23:25 ` Linus Walleij 2021-03-10 23:47 ` Doug Anderson 2021-03-10 23:47 ` Doug Anderson 2021-03-11 0:57 ` Linus Walleij 2021-03-11 0:57 ` Linus Walleij 2021-03-11 1:01 ` Doug Anderson 2021-03-11 1:01 ` Doug Anderson 2021-03-11 16:20 ` Linus Walleij 2021-03-11 16:20 ` Linus Walleij 2021-03-11 16:15 ` Linus Walleij 2021-03-11 16:15 ` Linus Walleij
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