Noted. Thanks for your consideration, Jani. Regards William
-----Original Message----- From: Jani Nikula <[email protected]> Sent: Wednesday, November 10, 2021 6:45 PM To: Tseng, William <[email protected]>; [email protected] Cc: Tseng, William <[email protected]>; Ville Syrjala <[email protected]>; Kulkarni, Vandita <[email protected]>; Lee, Shawn C <[email protected]>; Chiou, Cooper <[email protected]> Subject: Re: [PATCH v3] drm/i915/dsi: transmit brightness command in HS state On Wed, 10 Nov 2021, William Tseng <[email protected]> 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 <[email protected]> > Cc: Jani Nikula <[email protected]> > Cc: Vandita Kulkarni <[email protected]> > Cc: Lee Shawn C <[email protected]> > Cc: Cooper Chiou <[email protected]> > Signed-off-by: William Tseng <[email protected]> > --- > 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 <[email protected]> I'll push once CI results are in; had to request a re-run. > } > } -- Jani Nikula, Intel Open Source Graphics Center
