RE: [Intel-gfx] [PATCH v8 3/5] drm/i915: Add option to support dynamic backlight via DPCD

Yeah, looks fine to me.

-DK

From: puthik@google.com [mailto:puthik@google.com] On Behalf Of Puthikorn Voravootivat Sent: Friday, May 19, 2017 2:00 PM To: Pandiyan, Dhinakaran dhinakaran.pandiyan@intel.com Cc: puthik@chromium.org; dri-devel@lists.freedesktop.org; intel-gfx@lists.freedesktop.org; jani.nikula@linux.intel.com Subject: Re: [Intel-gfx] [PATCH v8 3/5] drm/i915: Add option to support dynamic backlight via DPCD

Hi Dhinakaran,

Quick question

So what is the update about adding new option in i915_params? Is this patch good to go after fixing the 2 points you mentioned?

Thanks

On Wed, May 17, 2017 at 1:33 PM, Pandiyan, Dhinakaran <dhinakaran.pandiyan@intel.commailto:dhinakaran.pandiyan@intel.com> wrote: On Tue, 2017-05-16 at 17:34 -0700, Puthikorn Voravootivat wrote:

This patch adds option to enable dynamic backlight for eDP panel that supports this feature via DPCD register and set minimum / maximum brightness to 0% and 100% of the normal brightness.

Signed-off-by: Puthikorn Voravootivat <puthik@chromium.orgmailto:puthik@chromium.org>

drivers/gpu/drm/i915/i915_params.c | 5 ++++ drivers/gpu/drm/i915/i915_params.h | 3 +- drivers/gpu/drm/i915/intel_dp_aux_backlight.c | 40 +++++++++++++++++++++++---- 3 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c index 13cf3f1572ab..6eaf660e74da 100644 --- a/drivers/gpu/drm/i915/i915_params.c +++ b/drivers/gpu/drm/i915/i915_params.c @@ -65,6 +65,7 @@ struct i915_params i915 __read_mostly = { .inject_load_failure = 0, .enable_dpcd_backlight = -1, .enable_gvt = false,

• .enable_dbc = false,
  

};

module_param_named(modeset, i915.modeset, int, 0400); @@ -255,3 +256,7 @@ MODULE_PARM_DESC(enable_dpcd_backlight, module_param_named(enable_gvt, i915.enable_gvt, bool, 0400); MODULE_PARM_DESC(enable_gvt, "Enable support for Intel GVT-g graphics virtualization host support(default:false)");

+module_param_named(enable_dbc, i915.enable_dbc, bool, 0600); +MODULE_PARM_DESC(enable_dbc,

• "Enable support for dynamic backlight control (default:false)");
  

diff --git a/drivers/gpu/drm/i915/i915_params.h b/drivers/gpu/drm/i915/i915_params.h index ac02efce6e22..2de3e2850b54 100644 --- a/drivers/gpu/drm/i915/i915_params.h +++ b/drivers/gpu/drm/i915/i915_params.h @@ -67,7 +67,8 @@ func(bool, nuclear_pageflip); \ func(bool, enable_dp_mst); \ func(int, enable_dpcd_backlight); \

• func(bool, enable_gvt)
  

• func(bool, enable_gvt); \
  

• func(bool, enable_dbc)
  
  

#define MEMBER(T, member) T member struct i915_params { diff --git a/drivers/gpu/drm/i915/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/intel_dp_aux_backlight.c index 16ba1924308d..c0eeb8fc2013 100644 --- a/drivers/gpu/drm/i915/intel_dp_aux_backlight.c +++ b/drivers/gpu/drm/i915/intel_dp_aux_backlight.c @@ -100,10 +100,27 @@ intel_dp_aux_set_backlight(struct intel_connector *connector, u32 level) } }

+/*

• • Set minimum / maximum dynamic brightness percentage. This value is expressed
• • as the percentage of normal brightness in 5% increments.
• */

+static void +intel_dp_aux_set_dynamic_backlight_percent(struct intel_dp *intel_dp,

•                                    u32 min, u32 max)
  

+{

• u8 dbc[] = { DIV_ROUND_CLOSEST(min, 5), DIV_ROUND_CLOSEST(max, 5) };
  

• if (drm_dp_dpcd_write(&intel_dp->aux, DP_EDP_DBC_MINIMUM_BRIGHTNESS_SET,
  

•                   dbc, sizeof(dbc) < 0)) {
  

Incorrect parentheses placement and return value check.

•         DRM_DEBUG_KMS("Failed to write aux DBC brightness level\n");
  

• }
  

+}

static void intel_dp_aux_enable_backlight(struct intel_connector *connector) { struct intel_dp *intel_dp = enc_to_intel_dp(&connector->encoder->base); uint8_t dpcd_buf = 0;

• uint8_t new_dpcd_buf = 0;
  

nit: unnecessary initialization.

  uint8_t edp_backlight_mode = 0;

  if (drm_dp_dpcd_readb(&intel_dp->aux,

@@ -113,18 +130,15 @@ static void intel_dp_aux_enable_backlight(struct intel_connector *connector) return; }

• new_dpcd_buf = dpcd_buf;
  edp_backlight_mode = dpcd_buf & DP_EDP_BACKLIGHT_CONTROL_MODE_MASK;
  
  switch (edp_backlight_mode) {
  case DP_EDP_BACKLIGHT_CONTROL_MODE_PWM:
  case DP_EDP_BACKLIGHT_CONTROL_MODE_PRESET:
  case DP_EDP_BACKLIGHT_CONTROL_MODE_PRODUCT:
  

•         dpcd_buf &= ~DP_EDP_BACKLIGHT_CONTROL_MODE_MASK;
  

•         dpcd_buf |= DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD;
  

•         if (drm_dp_dpcd_writeb(&intel_dp->aux,
  

•                 DP_EDP_BACKLIGHT_MODE_SET_REGISTER, dpcd_buf) < 0) {
  

•                 DRM_DEBUG_KMS("Failed to write aux backlight mode\n");
  

•         }
  

•         new_dpcd_buf &= ~DP_EDP_BACKLIGHT_CONTROL_MODE_MASK;
  

•         new_dpcd_buf |= DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD;
          break;
  
  /* Do nothing when it is already DPCD mode */
  

@@ -133,6 +147,20 @@ static void intel_dp_aux_enable_backlight(struct intel_connector *connector) break; }

• if (i915.enable_dbc &&
  

•     (intel_dp->edp_dpcd[2] & DP_EDP_DYNAMIC_BACKLIGHT_CAP)) {
  

•         new_dpcd_buf |= DP_EDP_DYNAMIC_BACKLIGHT_ENABLE;
  

•         intel_dp_aux_set_dynamic_backlight_percent(intel_dp, 0, 100);
  

•         DRM_DEBUG_KMS("Enable dynamic brightness.\n");
  

• }
  

• 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_DEBUG_KMS("Failed to write aux backlight mode\n");
  

•         }
  

• }
  

• set_aux_backlight_enable(intel_dp, true);
  intel_dp_aux_set_backlight(connector, connector->panel.backlight.level);
  

}