| Message ID | 20210901085445.427-6-shawn.c.lee@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | DSI driver improvement | expand |
On Wed, 01 Sep 2021, Lee Shawn C <shawn.c.lee@intel.com> wrote: > 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@intel.com> > Cc: Ville Syrjala <ville.syrjala@linux.intel.com> > Cc: Jani Nikula <jani.nikula@linux.intel.com> > Cc: Vandita Kulkarni <vandita.kulkarni@intel.com> > Cc: Cooper Chiou <cooper.chiou@intel.com> > Cc: William Tseng <william.tseng@intel.com> > Signed-off-by: Lee Shawn C <shawn.c.lee@intel.com> > --- > .../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}; u8 data[2] = {}; > enum port port; size_t len = panel->backlight.max > U8_MAX ? 2 : 1; > > /* 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]); Unnecessary braces around the whole thing. > } > > 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); I think it's confusing to use __be16 in set and u8 data[2] in get. Let's just use u8 data[2] in both. Especially because this one will always write 0 for len == 1 as it's big-endian data! You may have to do something like to keep it clear: size_t len = panel->backlight.max > U8_MAX ? 2 : 1; if (len == 1) { data[0] = level; } else { data[0] = level >> 8; data[1] = 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); > } > }
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); } }
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@intel.com> Cc: Ville Syrjala <ville.syrjala@linux.intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Vandita Kulkarni <vandita.kulkarni@intel.com> Cc: Cooper Chiou <cooper.chiou@intel.com> Cc: William Tseng <william.tseng@intel.com> Signed-off-by: Lee Shawn C <shawn.c.lee@intel.com> --- .../drm/i915/display/intel_dsi_dcs_backlight.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-)