Driver has to swap the endian before send brightness level value to tcon. v2: Use __be16 instead of u16 to fix sparse warning. v3: Send one or two bytes brightness value depend on the precision. Reported-by: kernel test robot <lkp@xxxxxxxxx> Cc: Ville Syrjala <ville.syrjala@xxxxxxxxxxxxxxx> Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> Cc: Vandita Kulkarni <vandita.kulkarni@xxxxxxxxx> Cc: Cooper Chiou <cooper.chiou@xxxxxxxxx> Cc: William Tseng <william.tseng@xxxxxxxxx> Signed-off-by: Lee Shawn C <shawn.c.lee@xxxxxxxxx> --- .../drm/i915/display/intel_dsi_dcs_backlight.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) 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 21ab9e1acb57..722411b5cb21 100644 --- a/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c +++ b/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c @@ -47,33 +47,36 @@ static u32 dcs_get_backlight(struct intel_connector *connector, enum pipe unused { struct intel_encoder *encoder = intel_attached_encoder(connector); struct intel_dsi *intel_dsi = enc_to_intel_dsi(encoder); + struct intel_panel *panel = &connector->panel; struct mipi_dsi_device *dsi_device; - u8 data = 0; + u8 data[2] = {0, 0}; enum port port; /* FIXME: Need to take care of 16 bit brightness level */ for_each_dsi_port(port, intel_dsi->dcs_backlight_ports) { dsi_device = intel_dsi->dsi_hosts[port]->device; mipi_dsi_dcs_read(dsi_device, MIPI_DCS_GET_DISPLAY_BRIGHTNESS, - &data, sizeof(data)); + &data, + (panel->backlight.max >> 8) ? sizeof(data) : 1); break; } - return data; + return ((data[1] << 8) | data[0]); } static void dcs_set_backlight(const struct drm_connector_state *conn_state, u32 level) { struct intel_dsi *intel_dsi = enc_to_intel_dsi(to_intel_encoder(conn_state->best_encoder)); + struct intel_panel *panel = &to_intel_connector(conn_state->connector)->panel; struct mipi_dsi_device *dsi_device; - u8 data = level; + __be16 data = cpu_to_be16(level); enum port port; - /* FIXME: Need to take care of 16 bit brightness level */ for_each_dsi_port(port, intel_dsi->dcs_backlight_ports) { dsi_device = intel_dsi->dsi_hosts[port]->device; mipi_dsi_dcs_write(dsi_device, MIPI_DCS_SET_DISPLAY_BRIGHTNESS, - &data, sizeof(data)); + &data, + (panel->backlight.max >> 8) ? sizeof(data) : 1); } } -- 2.17.1