| Message ID | 20211110010217.26759-1-william.tseng@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] drm/i915/dsi: transmit brightness command in HS state | expand |
On Wed, 10 Nov 2021, William Tseng <william.tseng@intel.com> wrote: > In Video Mode, if DSI transcoder is set to transmit packets > in LP Escape mode, screen flickering would be obseved when > brightness commands are continuously and quickly transmitted > to a panel. > > The problem may be resolved by changing the mode to transmit > packets from Low Power to HS. > > Cc: Ville Syrjala <ville.syrjala@linux.intel.com> > Cc: Jani Nikula <jani.nikula@linux.intel.com> > Cc: Vandita Kulkarni <vandita.kulkarni@intel.com> > Cc: Lee Shawn C <shawn.c.lee@intel.com> > Cc: Cooper Chiou <cooper.chiou@intel.com> > Signed-off-by: William Tseng <william.tseng@intel.com> > --- > drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c b/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c > index f61ed82e8867..7d234429e71e 100644 > --- a/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c > +++ b/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c > @@ -71,6 +71,7 @@ static void dcs_set_backlight(const struct drm_connector_state *conn_state, u32 > u8 data[2] = {}; > enum port port; > size_t len = panel->backlight.max > U8_MAX ? 2 : 1; > + unsigned long mode_flags; > > if (len == 1) { > data[0] = level; > @@ -81,8 +82,11 @@ static void dcs_set_backlight(const struct drm_connector_state *conn_state, u32 > > for_each_dsi_port(port, intel_dsi->dcs_backlight_ports) { > dsi_device = intel_dsi->dsi_hosts[port]->device; > + mode_flags = dsi_device->mode_flags; > + dsi_device->mode_flags &= ~MIPI_DSI_MODE_LPM; > mipi_dsi_dcs_write(dsi_device, MIPI_DCS_SET_DISPLAY_BRIGHTNESS, > &data, len); > + dsi_device->mode_flags = mode_flags; I realize we don't really have a clear picture how to manage ->mode_flags or MIPI_DSI_MODE_LPM in particular, but this seems like the safest option for now. Reviewed-by: Jani Nikula <jani.nikula@intel.com> I'll push once CI results are in; had to request a re-run. > } > }
Noted. Thanks for your consideration, Jani. Regards William -----Original Message----- From: Jani Nikula <jani.nikula@linux.intel.com> Sent: Wednesday, November 10, 2021 6:45 PM To: Tseng, William <william.tseng@intel.com>; intel-gfx@lists.freedesktop.org Cc: Tseng, William <william.tseng@intel.com>; Ville Syrjala <ville.syrjala@linux.intel.com>; Kulkarni, Vandita <vandita.kulkarni@intel.com>; Lee, Shawn C <shawn.c.lee@intel.com>; Chiou, Cooper <cooper.chiou@intel.com> Subject: Re: [PATCH v3] drm/i915/dsi: transmit brightness command in HS state On Wed, 10 Nov 2021, William Tseng <william.tseng@intel.com> wrote: > In Video Mode, if DSI transcoder is set to transmit packets in LP > Escape mode, screen flickering would be obseved when brightness > commands are continuously and quickly transmitted to a panel. > > The problem may be resolved by changing the mode to transmit packets > from Low Power to HS. > > Cc: Ville Syrjala <ville.syrjala@linux.intel.com> > Cc: Jani Nikula <jani.nikula@linux.intel.com> > Cc: Vandita Kulkarni <vandita.kulkarni@intel.com> > Cc: Lee Shawn C <shawn.c.lee@intel.com> > Cc: Cooper Chiou <cooper.chiou@intel.com> > Signed-off-by: William Tseng <william.tseng@intel.com> > --- > drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c > b/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c > index f61ed82e8867..7d234429e71e 100644 > --- a/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c > +++ b/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c > @@ -71,6 +71,7 @@ static void dcs_set_backlight(const struct drm_connector_state *conn_state, u32 > u8 data[2] = {}; > enum port port; > size_t len = panel->backlight.max > U8_MAX ? 2 : 1; > + unsigned long mode_flags; > > if (len == 1) { > data[0] = level; > @@ -81,8 +82,11 @@ static void dcs_set_backlight(const struct > drm_connector_state *conn_state, u32 > > for_each_dsi_port(port, intel_dsi->dcs_backlight_ports) { > dsi_device = intel_dsi->dsi_hosts[port]->device; > + mode_flags = dsi_device->mode_flags; > + dsi_device->mode_flags &= ~MIPI_DSI_MODE_LPM; > mipi_dsi_dcs_write(dsi_device, MIPI_DCS_SET_DISPLAY_BRIGHTNESS, > &data, len); > + dsi_device->mode_flags = mode_flags; I realize we don't really have a clear picture how to manage ->mode_flags or MIPI_DSI_MODE_LPM in particular, but this seems like the safest option for now. Reviewed-by: Jani Nikula <jani.nikula@intel.com> I'll push once CI results are in; had to request a re-run. > } > } -- Jani Nikula, Intel Open Source Graphics Center
On Thu, 11 Nov 2021, "Tseng, William" <william.tseng@intel.com> wrote: > Noted. Thanks for your consideration, Jani. And pushed, thanks for the patch. BR, Jani. > > Regards > William > > -----Original Message----- > From: Jani Nikula <jani.nikula@linux.intel.com> > Sent: Wednesday, November 10, 2021 6:45 PM > To: Tseng, William <william.tseng@intel.com>; intel-gfx@lists.freedesktop.org > Cc: Tseng, William <william.tseng@intel.com>; Ville Syrjala <ville.syrjala@linux.intel.com>; Kulkarni, Vandita <vandita.kulkarni@intel.com>; Lee, Shawn C <shawn.c.lee@intel.com>; Chiou, Cooper <cooper.chiou@intel.com> > Subject: Re: [PATCH v3] drm/i915/dsi: transmit brightness command in HS state > > On Wed, 10 Nov 2021, William Tseng <william.tseng@intel.com> wrote: >> In Video Mode, if DSI transcoder is set to transmit packets in LP >> Escape mode, screen flickering would be obseved when brightness >> commands are continuously and quickly transmitted to a panel. >> >> The problem may be resolved by changing the mode to transmit packets >> from Low Power to HS. >> >> Cc: Ville Syrjala <ville.syrjala@linux.intel.com> >> Cc: Jani Nikula <jani.nikula@linux.intel.com> >> Cc: Vandita Kulkarni <vandita.kulkarni@intel.com> >> Cc: Lee Shawn C <shawn.c.lee@intel.com> >> Cc: Cooper Chiou <cooper.chiou@intel.com> >> Signed-off-by: William Tseng <william.tseng@intel.com> >> --- >> drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c >> b/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c >> index f61ed82e8867..7d234429e71e 100644 >> --- a/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c >> +++ b/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c >> @@ -71,6 +71,7 @@ static void dcs_set_backlight(const struct drm_connector_state *conn_state, u32 >> u8 data[2] = {}; >> enum port port; >> size_t len = panel->backlight.max > U8_MAX ? 2 : 1; >> + unsigned long mode_flags; >> >> if (len == 1) { >> data[0] = level; >> @@ -81,8 +82,11 @@ static void dcs_set_backlight(const struct >> drm_connector_state *conn_state, u32 >> >> for_each_dsi_port(port, intel_dsi->dcs_backlight_ports) { >> dsi_device = intel_dsi->dsi_hosts[port]->device; >> + mode_flags = dsi_device->mode_flags; >> + dsi_device->mode_flags &= ~MIPI_DSI_MODE_LPM; >> mipi_dsi_dcs_write(dsi_device, MIPI_DCS_SET_DISPLAY_BRIGHTNESS, >> &data, len); >> + dsi_device->mode_flags = mode_flags; > > I realize we don't really have a clear picture how to manage > ->mode_flags or MIPI_DSI_MODE_LPM in particular, but this seems like the > safest option for now. > > Reviewed-by: Jani Nikula <jani.nikula@intel.com> > > I'll push once CI results are in; had to request a re-run. > > > >> } >> } > > -- > Jani Nikula, Intel Open Source Graphics Center
diff --git a/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c b/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c index f61ed82e8867..7d234429e71e 100644 --- a/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c +++ b/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c @@ -71,6 +71,7 @@ static void dcs_set_backlight(const struct drm_connector_state *conn_state, u32 u8 data[2] = {}; enum port port; size_t len = panel->backlight.max > U8_MAX ? 2 : 1; + unsigned long mode_flags; if (len == 1) { data[0] = level; @@ -81,8 +82,11 @@ static void dcs_set_backlight(const struct drm_connector_state *conn_state, u32 for_each_dsi_port(port, intel_dsi->dcs_backlight_ports) { dsi_device = intel_dsi->dsi_hosts[port]->device; + mode_flags = dsi_device->mode_flags; + dsi_device->mode_flags &= ~MIPI_DSI_MODE_LPM; mipi_dsi_dcs_write(dsi_device, MIPI_DCS_SET_DISPLAY_BRIGHTNESS, &data, len); + dsi_device->mode_flags = mode_flags; } }
In Video Mode, if DSI transcoder is set to transmit packets in LP Escape mode, screen flickering would be obseved when brightness commands are continuously and quickly transmitted to a panel. The problem may be resolved by changing the mode to transmit packets from Low Power to HS. Cc: Ville Syrjala <ville.syrjala@linux.intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Vandita Kulkarni <vandita.kulkarni@intel.com> Cc: Lee Shawn C <shawn.c.lee@intel.com> Cc: Cooper Chiou <cooper.chiou@intel.com> Signed-off-by: William Tseng <william.tseng@intel.com> --- drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c | 4 ++++ 1 file changed, 4 insertions(+)