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drm/i915/dpcd_bl: Print return codes for VESA backlight failures
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Also, stop printing the DPCD register that failed, and just describe it
instead. Saves us from having to look up each register offset when reading
through kernel logs (plus, DPCD dumping with drm.debug |= 0x100 will give
us that anyway).

Signed-off-by: Lyude Paul <[email protected]>
Reviewed-by: Rodrigo Vivi <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
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Lyude committed Jun 9, 2021
1 parent 17917ff commit 837f932
Showing 1 changed file with 52 additions and 49 deletions.
101 changes: 52 additions & 49 deletions drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
Original file line number Diff line number Diff line change
Expand Up @@ -274,14 +274,12 @@ static bool intel_dp_aux_vesa_backlight_dpcd_mode(struct intel_connector *connec
{
struct intel_dp *intel_dp = intel_attached_dp(connector);
struct drm_i915_private *i915 = dp_to_i915(intel_dp);
int ret;
u8 mode_reg;

if (drm_dp_dpcd_readb(&intel_dp->aux,
DP_EDP_BACKLIGHT_MODE_SET_REGISTER,
&mode_reg) != 1) {
drm_dbg_kms(&i915->drm,
"Failed to read the DPCD register 0x%x\n",
DP_EDP_BACKLIGHT_MODE_SET_REGISTER);
ret = drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &mode_reg);
if (ret != 1) {
drm_dbg_kms(&i915->drm, "Failed to read backlight mode: %d\n", ret);
return false;
}

Expand All @@ -297,6 +295,7 @@ static u32 intel_dp_aux_vesa_get_backlight(struct intel_connector *connector, en
{
struct intel_dp *intel_dp = intel_attached_dp(connector);
struct drm_i915_private *i915 = dp_to_i915(intel_dp);
int ret;
u8 read_val[2] = { 0x0 };
u16 level = 0;

Expand All @@ -307,10 +306,10 @@ 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)) != sizeof(read_val)) {
drm_dbg_kms(&i915->drm, "Failed to read DPCD register 0x%x\n",
DP_EDP_BACKLIGHT_BRIGHTNESS_MSB);
ret = drm_dp_dpcd_read(&intel_dp->aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, &read_val,
sizeof(read_val));
if (ret != sizeof(read_val)) {
drm_dbg_kms(&i915->drm, "Failed to read brightness level: %d\n", ret);
return 0;
}

Expand All @@ -333,6 +332,7 @@ intel_dp_aux_vesa_set_backlight(const struct drm_connector_state *conn_state,
struct intel_connector *connector = to_intel_connector(conn_state->connector);
struct intel_dp *intel_dp = intel_attached_dp(connector);
struct drm_i915_private *i915 = dp_to_i915(intel_dp);
int ret;
u8 vals[2] = { 0x0 };

/* Write the MSB and/or LSB */
Expand All @@ -343,10 +343,10 @@ intel_dp_aux_vesa_set_backlight(const struct drm_connector_state *conn_state,
vals[0] = level;
}

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");
ret = drm_dp_dpcd_write(&intel_dp->aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, vals,
sizeof(vals));
if (ret != sizeof(vals)) {
drm_dbg_kms(&i915->drm, "Failed to write aux backlight level: %d\n", ret);
return;
}
}
Expand All @@ -355,26 +355,28 @@ static void set_vesa_backlight_enable(struct intel_connector *connector, bool en
{
struct intel_dp *intel_dp = intel_attached_dp(connector);
struct drm_i915_private *i915 = dp_to_i915(intel_dp);
int ret;
u8 reg_val = 0;

/* Early return when display use other mechanism to enable backlight. */
if (!connector->panel.backlight.edp.vesa.aux_enable)
return;

if (drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_DISPLAY_CONTROL_REGISTER, &reg_val) != 1) {
drm_dbg_kms(&i915->drm, "Failed to read DPCD register 0x%x\n",
DP_EDP_DISPLAY_CONTROL_REGISTER);
ret = drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_DISPLAY_CONTROL_REGISTER, &reg_val);
if (ret != 1) {
drm_dbg_kms(&i915->drm, "Failed to read eDP display control register: %d\n", ret);
return;
}

if (enable)
reg_val |= DP_EDP_BACKLIGHT_ENABLE;
else
reg_val &= ~(DP_EDP_BACKLIGHT_ENABLE);

if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_DISPLAY_CONTROL_REGISTER,
reg_val) != 1) {
drm_dbg_kms(&i915->drm, "Failed to %s aux backlight\n",
enabledisable(enable));
ret = drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_DISPLAY_CONTROL_REGISTER, reg_val);
if (ret != 1) {
drm_dbg_kms(&i915->drm, "Failed to %s aux backlight: %d\n",
enabledisable(enable), ret);
}
}

Expand All @@ -386,13 +388,13 @@ intel_dp_aux_vesa_enable_backlight(const struct intel_crtc_state *crtc_state,
struct intel_dp *intel_dp = intel_attached_dp(connector);
struct drm_i915_private *i915 = dp_to_i915(intel_dp);
struct intel_panel *panel = &connector->panel;
int ret;
u8 dpcd_buf, new_dpcd_buf;
u8 pwmgen_bit_count = panel->backlight.edp.vesa.pwmgen_bit_count;

if (drm_dp_dpcd_readb(&intel_dp->aux,
DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &dpcd_buf) != 1) {
drm_dbg_kms(&i915->drm, "Failed to read DPCD register 0x%x\n",
DP_EDP_BACKLIGHT_MODE_SET_REGISTER);
ret = drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &dpcd_buf);
if (ret != 1) {
drm_dbg_kms(&i915->drm, "Failed to read backlight mode: %d\n", ret);
return;
}

Expand All @@ -402,24 +404,26 @@ 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) != 1)
drm_dbg_kms(&i915->drm,
"Failed to write aux pwmgen bit count\n");
ret = drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_PWMGEN_BIT_COUNT, pwmgen_bit_count);
if (ret != 1)
drm_dbg_kms(&i915->drm, "Failed to write aux pwmgen bit count: %d\n", ret);
}

if (panel->backlight.edp.vesa.pwm_freq_pre_divider) {
if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_BACKLIGHT_FREQ_SET,
panel->backlight.edp.vesa.pwm_freq_pre_divider) == 1)
ret = drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_BACKLIGHT_FREQ_SET,
panel->backlight.edp.vesa.pwm_freq_pre_divider);
if (ret == 1)
new_dpcd_buf |= DP_EDP_BACKLIGHT_FREQ_AUX_SET_ENABLE;
else
drm_dbg_kms(&i915->drm, "Failed to write aux backlight frequency\n");
drm_dbg_kms(&i915->drm, "Failed to write aux backlight frequency: %d\n",
ret);
}

if (new_dpcd_buf != dpcd_buf) {
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");
ret = drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER,
new_dpcd_buf);
if (ret != 1)
drm_dbg_kms(&i915->drm, "Failed to write aux backlight mode: %d\n", ret);
}

intel_dp_aux_vesa_set_backlight(conn_state, level);
Expand All @@ -446,11 +450,12 @@ static u32 intel_dp_aux_vesa_calc_max_backlight(struct intel_connector *connecto
struct intel_dp *intel_dp = intel_attached_dp(connector);
struct intel_panel *panel = &connector->panel;
u32 max_backlight = 0;
int freq, fxp, fxp_min, fxp_max, fxp_actual, f = 1;
int ret, freq, fxp, fxp_min, fxp_max, fxp_actual, f = 1;
u8 pn, pn_min, pn_max;

if (drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_PWMGEN_BIT_COUNT, &pn) != 1) {
drm_dbg_kms(&i915->drm, "Failed to read pwmgen bit count cap\n");
ret = drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_PWMGEN_BIT_COUNT, &pn);
if (ret != 1) {
drm_dbg_kms(&i915->drm, "Failed to read pwmgen bit count cap: %d\n", ret);
return 0;
}

Expand Down Expand Up @@ -479,16 +484,14 @@ static u32 intel_dp_aux_vesa_calc_max_backlight(struct intel_connector *connecto
* - FxP is within 25% of desired value.
* Note: 25% is arbitrary value and may need some tweak.
*/
if (drm_dp_dpcd_readb(&intel_dp->aux,
DP_EDP_PWMGEN_BIT_COUNT_CAP_MIN, &pn_min) != 1) {
drm_dbg_kms(&i915->drm,
"Failed to read pwmgen bit count cap min\n");
ret = drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_PWMGEN_BIT_COUNT_CAP_MIN, &pn_min);
if (ret != 1) {
drm_dbg_kms(&i915->drm, "Failed to read pwmgen bit count cap min: %d\n", ret);
return max_backlight;
}
if (drm_dp_dpcd_readb(&intel_dp->aux,
DP_EDP_PWMGEN_BIT_COUNT_CAP_MAX, &pn_max) != 1) {
drm_dbg_kms(&i915->drm,
"Failed to read pwmgen bit count cap max\n");
ret = drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_PWMGEN_BIT_COUNT_CAP_MAX, &pn_max);
if (ret != 1) {
drm_dbg_kms(&i915->drm, "Failed to read pwmgen bit count cap max: %d\n", ret);
return max_backlight;
}
pn_min &= DP_EDP_PWMGEN_BIT_COUNT_MASK;
Expand All @@ -512,9 +515,9 @@ 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) != 1) {
drm_dbg_kms(&i915->drm,
"Failed to write aux pwmgen bit count\n");
ret = drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_PWMGEN_BIT_COUNT, pn);
if (ret != 1) {
drm_dbg_kms(&i915->drm, "Failed to write aux pwmgen bit count: %d\n", ret);
return max_backlight;
}

Expand Down

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