| Message ID | 20211109082458.13740-1-william.tseng@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] drm/i915/dsi: transmit brightness command in HS state | expand |
On Tue, 09 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 | 2 ++ > 1 file changed, 2 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..2f788cb0f597 100644 > --- a/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c > +++ b/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c > @@ -81,8 +81,10 @@ 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; > + 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 |= MIPI_DSI_MODE_LPM; Ah, but this doesn't *restore* the flags, it forces MIPI_DSI_MODE_LPM! BR, Jani. > } > }
Thanks, Jani. That does not restore the mode flags perfectly. I will revise the patch. Regards William -----Original Message----- From: Jani Nikula <jani.nikula@linux.intel.com> Sent: Tuesday, November 9, 2021 6:41 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 v2] drm/i915/dsi: transmit brightness command in HS state On Tue, 09 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 | 2 ++ > 1 file changed, 2 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..2f788cb0f597 100644 > --- a/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c > +++ b/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c > @@ -81,8 +81,10 @@ 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; > + 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 |= MIPI_DSI_MODE_LPM; Ah, but this doesn't *restore* the flags, it forces MIPI_DSI_MODE_LPM! BR, Jani. > } > } -- 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..2f788cb0f597 100644 --- a/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c +++ b/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c @@ -81,8 +81,10 @@ 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; + 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 |= MIPI_DSI_MODE_LPM; } }
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 | 2 ++ 1 file changed, 2 insertions(+)