This is kind of an annoying aspect of DRM's DP helpers: drm_dp_dpcd_readb/writeb() return the size of bytes read/written on success, thus we want to check against that instead of checking if the return value is less than 0.
I'll probably be fixing this in the near future once I start doing DP work again, also because I'd rather not mix a tree-wide refactor like that in with a patch series intended to be around introducing DP backlight helpers. So, for now let's just handle the return values from each function correctly.
Signed-off-by: Lyude Paul lyude@redhat.com Reviewed-by: Rodrigo Vivi rodrigo.vivi@intel.com --- .../drm/i915/display/intel_dp_aux_backlight.c | 41 +++++++++---------- 1 file changed, 19 insertions(+), 22 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c index 62294967f430..c37ccc8538cb 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c @@ -107,7 +107,7 @@ intel_dp_aux_supports_hdr_backlight(struct intel_connector *connector) u8 tcon_cap[4];
ret = drm_dp_dpcd_read(aux, INTEL_EDP_HDR_TCON_CAP0, tcon_cap, sizeof(tcon_cap)); - if (ret < 0) + if (ret != sizeof(tcon_cap)) return false;
if (!(tcon_cap[1] & INTEL_EDP_HDR_TCON_BRIGHTNESS_NITS_CAP)) @@ -137,7 +137,7 @@ intel_dp_aux_hdr_get_backlight(struct intel_connector *connector, enum pipe pipe u8 tmp; u8 buf[2] = { 0 };
- if (drm_dp_dpcd_readb(&intel_dp->aux, INTEL_EDP_HDR_GETSET_CTRL_PARAMS, &tmp) < 0) { + if (drm_dp_dpcd_readb(&intel_dp->aux, INTEL_EDP_HDR_GETSET_CTRL_PARAMS, &tmp) != 1) { drm_err(&i915->drm, "Failed to read current backlight mode from DPCD\n"); return 0; } @@ -153,7 +153,8 @@ intel_dp_aux_hdr_get_backlight(struct intel_connector *connector, enum pipe pipe return panel->backlight.max; }
- if (drm_dp_dpcd_read(&intel_dp->aux, INTEL_EDP_BRIGHTNESS_NITS_LSB, buf, sizeof(buf)) < 0) { + if (drm_dp_dpcd_read(&intel_dp->aux, INTEL_EDP_BRIGHTNESS_NITS_LSB, buf, + sizeof(buf)) != sizeof(buf)) { drm_err(&i915->drm, "Failed to read brightness from DPCD\n"); return 0; } @@ -172,7 +173,8 @@ intel_dp_aux_hdr_set_aux_backlight(const struct drm_connector_state *conn_state, buf[0] = level & 0xFF; buf[1] = (level & 0xFF00) >> 8;
- if (drm_dp_dpcd_write(&intel_dp->aux, INTEL_EDP_BRIGHTNESS_NITS_LSB, buf, 4) < 0) + if (drm_dp_dpcd_write(&intel_dp->aux, INTEL_EDP_BRIGHTNESS_NITS_LSB, buf, + sizeof(buf)) != sizeof(buf)) drm_err(dev, "Failed to write brightness level to DPCD\n"); }
@@ -203,7 +205,7 @@ intel_dp_aux_hdr_enable_backlight(const struct intel_crtc_state *crtc_state, u8 old_ctrl, ctrl;
ret = drm_dp_dpcd_readb(&intel_dp->aux, INTEL_EDP_HDR_GETSET_CTRL_PARAMS, &old_ctrl); - if (ret < 0) { + if (ret != 1) { drm_err(&i915->drm, "Failed to read current backlight control mode: %d\n", ret); return; } @@ -221,7 +223,7 @@ intel_dp_aux_hdr_enable_backlight(const struct intel_crtc_state *crtc_state, }
if (ctrl != old_ctrl) - if (drm_dp_dpcd_writeb(&intel_dp->aux, INTEL_EDP_HDR_GETSET_CTRL_PARAMS, ctrl) < 0) + if (drm_dp_dpcd_writeb(&intel_dp->aux, INTEL_EDP_HDR_GETSET_CTRL_PARAMS, ctrl) != 1) drm_err(&i915->drm, "Failed to configure DPCD brightness controls\n"); }
@@ -277,8 +279,7 @@ static void set_vesa_backlight_enable(struct intel_dp *intel_dp, bool enable) if (!(intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP)) return;
- if (drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_DISPLAY_CONTROL_REGISTER, - ®_val) < 0) { + if (drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_DISPLAY_CONTROL_REGISTER, ®_val) != 1) { drm_dbg_kms(&i915->drm, "Failed to read DPCD register 0x%x\n", DP_EDP_DISPLAY_CONTROL_REGISTER); return; @@ -332,8 +333,8 @@ static u32 intel_dp_aux_vesa_get_backlight(struct intel_connector *connector, en if (!intel_dp_aux_vesa_backlight_dpcd_mode(connector)) return connector->panel.backlight.max;
- if (drm_dp_dpcd_read(&intel_dp->aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, - &read_val, sizeof(read_val)) < 0) { + if (drm_dp_dpcd_read(&intel_dp->aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, &read_val, + sizeof(read_val)) != sizeof(read_val)) { drm_dbg_kms(&i915->drm, "Failed to read DPCD register 0x%x\n", DP_EDP_BACKLIGHT_BRIGHTNESS_MSB); return 0; @@ -365,8 +366,8 @@ intel_dp_aux_vesa_set_backlight(const struct drm_connector_state *conn_state, vals[0] = (level & 0xFF00) >> 8; vals[1] = (level & 0xFF); } - if (drm_dp_dpcd_write(&intel_dp->aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, - vals, sizeof(vals)) < 0) { + if (drm_dp_dpcd_write(&intel_dp->aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, vals, + sizeof(vals)) != sizeof(vals)) { drm_dbg_kms(&i915->drm, "Failed to write aux backlight level\n"); return; @@ -401,9 +402,8 @@ intel_dp_aux_vesa_enable_backlight(const struct intel_crtc_state *crtc_state, new_dpcd_buf &= ~DP_EDP_BACKLIGHT_CONTROL_MODE_MASK; new_dpcd_buf |= DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD;
- if (drm_dp_dpcd_writeb(&intel_dp->aux, - DP_EDP_PWMGEN_BIT_COUNT, - pwmgen_bit_count) < 0) + if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_PWMGEN_BIT_COUNT, + pwmgen_bit_count) != 1) drm_dbg_kms(&i915->drm, "Failed to write aux pwmgen bit count\n");
@@ -424,11 +424,9 @@ intel_dp_aux_vesa_enable_backlight(const struct intel_crtc_state *crtc_state, }
if (new_dpcd_buf != dpcd_buf) { - if (drm_dp_dpcd_writeb(&intel_dp->aux, - DP_EDP_BACKLIGHT_MODE_SET_REGISTER, new_dpcd_buf) < 0) { - drm_dbg_kms(&i915->drm, - "Failed to write aux backlight mode\n"); - } + if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, + new_dpcd_buf) != 1) + drm_dbg_kms(&i915->drm, "Failed to write aux backlight mode\n"); }
intel_dp_aux_vesa_set_backlight(conn_state, level); @@ -519,8 +517,7 @@ static u32 intel_dp_aux_vesa_calc_max_backlight(struct intel_connector *connecto }
drm_dbg_kms(&i915->drm, "Using eDP pwmgen bit count of %d\n", pn); - if (drm_dp_dpcd_writeb(&intel_dp->aux, - DP_EDP_PWMGEN_BIT_COUNT, pn) < 0) { + if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_PWMGEN_BIT_COUNT, pn) != 1) { drm_dbg_kms(&i915->drm, "Failed to write aux pwmgen bit count\n"); return max_backlight;