drivers/gpu/drm/panel/panel-edp.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-)
In eDP power-off timing specifications, T10 defines the minimum delay
required between the end of valid video data from the source and panel
power-down (main VDD off).
Currently, panel-edp only supports the 'disable' delay, which corresponds
to T9 (backlight off to end of video data) and runs in panel_edp_disable()
while video data is still active. For panels that require a delay after
video data has stopped before cutting power, this delay must occur in
panel_edp_unprepare() before turning off power rails.
Add a 'pre_unprepare' field to struct panel_delay to model T10-min, and
delay for this duration in panel_edp_unprepare() before calling
pm_runtime_put_sync_suspend().
Additionally, adjust the timing entry for TM156VDXP25 to use
delay_200_500_e80_pu100 (enable = 80ms, pre_unprepare = 100ms) to match
its panel specification, replacing the previous delay_200_500_e50_d100.
Fixes: b9e2d5cdaab0 ("drm/panel-edp: Support NV140FHM-N5B and TM156VDXP25")
Signed-off-by: Hsin-Te Yuan <yuanhsinte@chromium.org>
---
Change-Id: I3361bdf4d3289c773f0c2b77163e427b774797d5
---
drivers/gpu/drm/panel/panel-edp.c | 23 ++++++++++++++++++++++-
1 file changed, 22 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/panel/panel-edp.c b/drivers/gpu/drm/panel/panel-edp.c
index 98bdcf352701..f6624191f97c 100644
--- a/drivers/gpu/drm/panel/panel-edp.c
+++ b/drivers/gpu/drm/panel/panel-edp.c
@@ -144,6 +144,16 @@ struct panel_delay {
*/
unsigned int disable;
+ /**
+ * @pre_unprepare: Time for the end of video data to power off.
+ *
+ * The time (in milliseconds) that it needs to have passed between
+ * the end of valid video data from source and start powering off.
+ *
+ * This is T10-min on eDP timing diagrams. It is not common to set.
+ */
+ unsigned int pre_unprepare;
+
/**
* @unprepare: Time to power down completely.
*
@@ -413,8 +423,12 @@ static int panel_edp_suspend(struct device *dev)
static int panel_edp_unprepare(struct drm_panel *panel)
{
+ struct panel_edp *p = to_panel_edp(panel);
int ret;
+ if (p->desc->delay.pre_unprepare)
+ msleep(p->desc->delay.pre_unprepare);
+
ret = pm_runtime_put_sync_suspend(panel->dev);
if (ret < 0)
return ret;
@@ -1810,6 +1824,13 @@ static const struct panel_delay delay_80_500_e80_p2e200 = {
.prepare_to_enable = 200,
};
+static const struct panel_delay delay_200_500_e80_pu100 = {
+ .hpd_absent = 200,
+ .unprepare = 500,
+ .enable = 80,
+ .pre_unprepare = 100,
+};
+
static const struct panel_delay delay_100_500_e200 = {
.hpd_absent = 100,
.unprepare = 500,
@@ -2181,7 +2202,7 @@ static const struct edp_panel_entry edp_panels[] = {
EDP_PANEL_ENTRY('T', 'M', 'A', 0x0811, &delay_200_500_e80_d50, "TM140VDXP01-04"),
EDP_PANEL_ENTRY('T', 'M', 'A', 0x2094, &delay_200_500_e50_d100, "TL140VDMS03-01"),
- EDP_PANEL_ENTRY('T', 'M', 'A', 0x2139, &delay_200_500_e50_d100, "TM156VDXP25"),
+ EDP_PANEL_ENTRY('T', 'M', 'A', 0x2139, &delay_200_500_e80_pu100, "TM156VDXP25"),
{ /* sentinal */ }
};
---
base-commit: bc47d5937f21c5fc94504f03e18f1adb56d97634
change-id: 20260803-edp-5a804f897d02
Best regards,
--
Hsin-Te Yuan <yuanhsinte@chromium.org>Hi,
On Mon, Aug 3, 2026 at 2:47 AM Hsin-Te Yuan <yuanhsinte@chromium.org> wrote:
>
> In eDP power-off timing specifications, T10 defines the minimum delay
> required between the end of valid video data from the source and panel
> power-down (main VDD off).
>
> Currently, panel-edp only supports the 'disable' delay, which corresponds
> to T9 (backlight off to end of video data) and runs in panel_edp_disable()
> while video data is still active. For panels that require a delay after
> video data has stopped before cutting power, this delay must occur in
> panel_edp_unprepare() before turning off power rails.
>
> Add a 'pre_unprepare' field to struct panel_delay to model T10-min, and
> delay for this duration in panel_edp_unprepare() before calling
> pm_runtime_put_sync_suspend().
>
> Additionally, adjust the timing entry for TM156VDXP25 to use
> delay_200_500_e80_pu100 (enable = 80ms, pre_unprepare = 100ms) to match
> its panel specification, replacing the previous delay_200_500_e50_d100.
>
> Fixes: b9e2d5cdaab0 ("drm/panel-edp: Support NV140FHM-N5B and TM156VDXP25")
> Signed-off-by: Hsin-Te Yuan <yuanhsinte@chromium.org>
> ---
> Change-Id: I3361bdf4d3289c773f0c2b77163e427b774797d5
> ---
> drivers/gpu/drm/panel/panel-edp.c | 23 ++++++++++++++++++++++-
> 1 file changed, 22 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/panel/panel-edp.c b/drivers/gpu/drm/panel/panel-edp.c
> index 98bdcf352701..f6624191f97c 100644
> --- a/drivers/gpu/drm/panel/panel-edp.c
> +++ b/drivers/gpu/drm/panel/panel-edp.c
> @@ -144,6 +144,16 @@ struct panel_delay {
> */
> unsigned int disable;
>
> + /**
> + * @pre_unprepare: Time for the end of video data to power off.
> + *
> + * The time (in milliseconds) that it needs to have passed between
> + * the end of valid video data from source and start powering off.
> + *
> + * This is T10-min on eDP timing diagrams. It is not common to set.
> + */
> + unsigned int pre_unprepare;
> +
> /**
> * @unprepare: Time to power down completely.
> *
> @@ -413,8 +423,12 @@ static int panel_edp_suspend(struct device *dev)
>
> static int panel_edp_unprepare(struct drm_panel *panel)
> {
> + struct panel_edp *p = to_panel_edp(panel);
> int ret;
>
> + if (p->desc->delay.pre_unprepare)
> + msleep(p->desc->delay.pre_unprepare);
> +
> ret = pm_runtime_put_sync_suspend(panel->dev);
> if (ret < 0)
> return ret;
> @@ -1810,6 +1824,13 @@ static const struct panel_delay delay_80_500_e80_p2e200 = {
> .prepare_to_enable = 200,
> };
>
> +static const struct panel_delay delay_200_500_e80_pu100 = {
> + .hpd_absent = 200,
> + .unprepare = 500,
> + .enable = 80,
> + .pre_unprepare = 100,
> +};
> +
> static const struct panel_delay delay_100_500_e200 = {
> .hpd_absent = 100,
> .unprepare = 500,
> @@ -2181,7 +2202,7 @@ static const struct edp_panel_entry edp_panels[] = {
>
> EDP_PANEL_ENTRY('T', 'M', 'A', 0x0811, &delay_200_500_e80_d50, "TM140VDXP01-04"),
> EDP_PANEL_ENTRY('T', 'M', 'A', 0x2094, &delay_200_500_e50_d100, "TL140VDMS03-01"),
> - EDP_PANEL_ENTRY('T', 'M', 'A', 0x2139, &delay_200_500_e50_d100, "TM156VDXP25"),
> + EDP_PANEL_ENTRY('T', 'M', 'A', 0x2139, &delay_200_500_e80_pu100, "TM156VDXP25"),
Looks OK to me. Thank you for the thorough description.
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Do you happen to know if any of the other TMA panels should also get
this updated timing?
My thought would be to land this in drm-misc-next instead of
drm-misc-fixes. Is that OK w/ you? I assume you just need a stable git
hash to pick and it's not urgent for you to get this in through stable
trees. Getting the updated timings is usually not massively
time-critical and having bake time / avoiding merge conflicts is
nice...
Assuming nothing else comes up, I'll try to land in the next few days.
Usually I don't delay at all for panel timings, but since this changes
an old panel I'll at least give it an extra day or two...
-Doug
On Tue, Aug 4, 2026 at 3:50 AM Doug Anderson <dianders@chromium.org> wrote:
>
> Hi,
>
> On Mon, Aug 3, 2026 at 2:47 AM Hsin-Te Yuan <yuanhsinte@chromium.org> wrote:
> >
> > In eDP power-off timing specifications, T10 defines the minimum delay
> > required between the end of valid video data from the source and panel
> > power-down (main VDD off).
> >
> > Currently, panel-edp only supports the 'disable' delay, which corresponds
> > to T9 (backlight off to end of video data) and runs in panel_edp_disable()
> > while video data is still active. For panels that require a delay after
> > video data has stopped before cutting power, this delay must occur in
> > panel_edp_unprepare() before turning off power rails.
> >
> > Add a 'pre_unprepare' field to struct panel_delay to model T10-min, and
> > delay for this duration in panel_edp_unprepare() before calling
> > pm_runtime_put_sync_suspend().
> >
> > Additionally, adjust the timing entry for TM156VDXP25 to use
> > delay_200_500_e80_pu100 (enable = 80ms, pre_unprepare = 100ms) to match
> > its panel specification, replacing the previous delay_200_500_e50_d100.
> >
> > Fixes: b9e2d5cdaab0 ("drm/panel-edp: Support NV140FHM-N5B and TM156VDXP25")
> > Signed-off-by: Hsin-Te Yuan <yuanhsinte@chromium.org>
> > ---
> > Change-Id: I3361bdf4d3289c773f0c2b77163e427b774797d5
> > ---
> > drivers/gpu/drm/panel/panel-edp.c | 23 ++++++++++++++++++++++-
> > 1 file changed, 22 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/panel/panel-edp.c b/drivers/gpu/drm/panel/panel-edp.c
> > index 98bdcf352701..f6624191f97c 100644
> > --- a/drivers/gpu/drm/panel/panel-edp.c
> > +++ b/drivers/gpu/drm/panel/panel-edp.c
> > @@ -144,6 +144,16 @@ struct panel_delay {
> > */
> > unsigned int disable;
> >
> > + /**
> > + * @pre_unprepare: Time for the end of video data to power off.
> > + *
> > + * The time (in milliseconds) that it needs to have passed between
> > + * the end of valid video data from source and start powering off.
> > + *
> > + * This is T10-min on eDP timing diagrams. It is not common to set.
> > + */
> > + unsigned int pre_unprepare;
> > +
> > /**
> > * @unprepare: Time to power down completely.
> > *
> > @@ -413,8 +423,12 @@ static int panel_edp_suspend(struct device *dev)
> >
> > static int panel_edp_unprepare(struct drm_panel *panel)
> > {
> > + struct panel_edp *p = to_panel_edp(panel);
> > int ret;
> >
> > + if (p->desc->delay.pre_unprepare)
> > + msleep(p->desc->delay.pre_unprepare);
> > +
> > ret = pm_runtime_put_sync_suspend(panel->dev);
> > if (ret < 0)
> > return ret;
> > @@ -1810,6 +1824,13 @@ static const struct panel_delay delay_80_500_e80_p2e200 = {
> > .prepare_to_enable = 200,
> > };
> >
> > +static const struct panel_delay delay_200_500_e80_pu100 = {
> > + .hpd_absent = 200,
> > + .unprepare = 500,
> > + .enable = 80,
> > + .pre_unprepare = 100,
> > +};
> > +
> > static const struct panel_delay delay_100_500_e200 = {
> > .hpd_absent = 100,
> > .unprepare = 500,
> > @@ -2181,7 +2202,7 @@ static const struct edp_panel_entry edp_panels[] = {
> >
> > EDP_PANEL_ENTRY('T', 'M', 'A', 0x0811, &delay_200_500_e80_d50, "TM140VDXP01-04"),
> > EDP_PANEL_ENTRY('T', 'M', 'A', 0x2094, &delay_200_500_e50_d100, "TL140VDMS03-01"),
> > - EDP_PANEL_ENTRY('T', 'M', 'A', 0x2139, &delay_200_500_e50_d100, "TM156VDXP25"),
> > + EDP_PANEL_ENTRY('T', 'M', 'A', 0x2139, &delay_200_500_e80_pu100, "TM156VDXP25"),
>
> Looks OK to me. Thank you for the thorough description.
>
> Reviewed-by: Douglas Anderson <dianders@chromium.org>
>
> Do you happen to know if any of the other TMA panels should also get
> this updated timing?
>
No, this is the only one the ODM reported so far.
>
> My thought would be to land this in drm-misc-next instead of
> drm-misc-fixes. Is that OK w/ you? I assume you just need a stable git
> hash to pick and it's not urgent for you to get this in through stable
> trees. Getting the updated timings is usually not massively
> time-critical and having bake time / avoiding merge conflicts is
> nice...
Yes, I'm fine with that. Actually the original commit is still in drm-misc-next,
so I guess this can't be landed in drm-misc-fixes.
>
> Assuming nothing else comes up, I'll try to land in the next few days.
> Usually I don't delay at all for panel timings, but since this changes
> an old panel I'll at least give it an extra day or two...
>
> -Doug
Regards,
Hsin-Te
Hi,
On Wed, Aug 5, 2026 at 4:11 AM Hsin-Te Yuan <yuanhsinte@chromium.org> wrote:
>
> > Looks OK to me. Thank you for the thorough description.
> >
> > Reviewed-by: Douglas Anderson <dianders@chromium.org>
> >
> > Do you happen to know if any of the other TMA panels should also get
> > this updated timing?
> >
> No, this is the only one the ODM reported so far.
> >
> > My thought would be to land this in drm-misc-next instead of
> > drm-misc-fixes. Is that OK w/ you? I assume you just need a stable git
> > hash to pick and it's not urgent for you to get this in through stable
> > trees. Getting the updated timings is usually not massively
> > time-critical and having bake time / avoiding merge conflicts is
> > nice...
> Yes, I'm fine with that. Actually the original commit is still in drm-misc-next,
> so I guess this can't be landed in drm-misc-fixes.
> >
> > Assuming nothing else comes up, I'll try to land in the next few days.
> > Usually I don't delay at all for panel timings, but since this changes
> > an old panel I'll at least give it an extra day or two...
Pushed to drm-misc-next:
[1/1] drm/panel-edp: Add pre_unprepare delay
commit: c8d3d795dd40c7fb35b39ebcb99ae5f2f1884b48
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