From: Vasily Khoruzhick <anarsoul@gmail.com> To: Jani Nikula <jani.nikula@linux.intel.com>, Joonas Lahtinen <joonas.lahtinen@linux.intel.com>, Rodrigo Vivi <rodrigo.vivi@intel.com>, David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>, Lyude Paul <lyude@redhat.com>, Sean Paul <seanpaul@chromium.org>, Aaron Ma <aaron.ma@canonical.com>, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Cc: Vasily Khoruzhick <anarsoul@gmail.com> Subject: [PATCH] drm/i915/dp: add a delay before setting panel brightness after power on Date: Mon, 13 Sep 2021 12:35:09 -0700 [thread overview] Message-ID: <20210913193509.3575-1-anarsoul@gmail.com> (raw) Panel in my Dell XPS 7590, that uses Intel's HDR backlight interface to control brightness, apparently needs a delay before setting brightness after power on. Without this delay the panel does accept the setting and may come up with some arbitrary brightness (sometimes it's too dark, sometimes it's too bright, I wasn't able to find a system). I don't have access to the spec, so I'm not sure if it's expected behavior or a quirk for particular device. Delay was chosen by experiment: it works with 100ms, but fails with anything lower than 75ms. Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com> --- drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c index 4f8337c7fd2e..c4f35e1b5870 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c @@ -210,6 +210,10 @@ intel_dp_aux_hdr_enable_backlight(const struct intel_crtc_state *crtc_state, ctrl = old_ctrl; if (panel->backlight.edp.intel.sdr_uses_aux) { + /* Wait 100ms to ensure that panel is ready otherwise it may not + * set chosen backlight level + */ + msleep(100); ctrl |= INTEL_EDP_HDR_TCON_BRIGHTNESS_AUX_ENABLE; intel_dp_aux_hdr_set_aux_backlight(conn_state, level); } else { -- 2.33.0
WARNING: multiple messages have this Message-ID (diff)
From: Vasily Khoruzhick <anarsoul@gmail.com> To: Jani Nikula <jani.nikula@linux.intel.com>, Joonas Lahtinen <joonas.lahtinen@linux.intel.com>, Rodrigo Vivi <rodrigo.vivi@intel.com>, David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>, Lyude Paul <lyude@redhat.com>, Sean Paul <seanpaul@chromium.org>, Aaron Ma <aaron.ma@canonical.com>, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Cc: Vasily Khoruzhick <anarsoul@gmail.com> Subject: [Intel-gfx] [PATCH] drm/i915/dp: add a delay before setting panel brightness after power on Date: Mon, 13 Sep 2021 12:35:09 -0700 [thread overview] Message-ID: <20210913193509.3575-1-anarsoul@gmail.com> (raw) Panel in my Dell XPS 7590, that uses Intel's HDR backlight interface to control brightness, apparently needs a delay before setting brightness after power on. Without this delay the panel does accept the setting and may come up with some arbitrary brightness (sometimes it's too dark, sometimes it's too bright, I wasn't able to find a system). I don't have access to the spec, so I'm not sure if it's expected behavior or a quirk for particular device. Delay was chosen by experiment: it works with 100ms, but fails with anything lower than 75ms. Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com> --- drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c index 4f8337c7fd2e..c4f35e1b5870 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c @@ -210,6 +210,10 @@ intel_dp_aux_hdr_enable_backlight(const struct intel_crtc_state *crtc_state, ctrl = old_ctrl; if (panel->backlight.edp.intel.sdr_uses_aux) { + /* Wait 100ms to ensure that panel is ready otherwise it may not + * set chosen backlight level + */ + msleep(100); ctrl |= INTEL_EDP_HDR_TCON_BRIGHTNESS_AUX_ENABLE; intel_dp_aux_hdr_set_aux_backlight(conn_state, level); } else { -- 2.33.0
next reply other threads:[~2021-09-13 19:35 UTC|newest] Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-09-13 19:35 Vasily Khoruzhick [this message] 2021-09-13 19:35 ` [Intel-gfx] [PATCH] drm/i915/dp: add a delay before setting panel brightness after power on Vasily Khoruzhick 2021-09-13 22:34 ` [Intel-gfx] ✓ Fi.CI.BAT: success for " Patchwork 2021-09-14 1:58 ` [Intel-gfx] ✓ Fi.CI.IGT: " Patchwork 2021-09-14 9:09 ` [PATCH] " Jani Nikula 2021-09-14 9:09 ` [Intel-gfx] " Jani Nikula 2021-09-14 21:08 ` Lyude Paul 2021-09-14 21:08 ` [Intel-gfx] " Lyude Paul 2021-09-14 22:31 ` Jani Nikula 2021-09-14 22:31 ` [Intel-gfx] " Jani Nikula 2021-09-15 1:10 ` Vasily Khoruzhick 2021-09-15 1:10 ` [Intel-gfx] " Vasily Khoruzhick 2021-09-15 8:47 ` Jani Nikula 2021-09-15 8:47 ` [Intel-gfx] " Jani Nikula 2021-09-20 6:57 ` Vasily Khoruzhick 2021-09-20 6:57 ` [Intel-gfx] " Vasily Khoruzhick
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