On Fri, May 12, 2017 at 6:14 AM, Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> wrote:
On Fri, 12 May 2017, "Pandiyan, Dhinakaran" <dhinakaran.pandiyan@xxxxxxxxx> wrote: Puthikorn, please don't send new versions before the review is
> On Thu, 2017-05-11 at 16:02 -0700, Puthikorn Voravootivat wrote:
>> There are some panel that
>> (1) does not support display backlight enable via AUX
>> (2) support display backlight adjustment via AUX
>> (3) support display backlight enable via eDP BL_ENABLE pin
>>
>> The current driver required that (1) must be support to enable (2).
>> This patch drops that requirement.
>>
>
> You sent this version before I finished my follow-up questions, copying
> the conversation here for context.
addressed.
Sorry I thought I was explained it clear enough.
Pushed patches 1, 2, 5, and 7. Thanks for the patches and review.
BR,
Jani.
> DK: Won't DP_EDP_BACKLIGHT_AUX_ENABLE_CAP be 1 always? The code below,
> in
> intel_dp_aux_display_control_capable(), makes sure
> DP_EDP_BACKLIGHT_PIN_ENABLE_CAP=0. The spec says at least one of these
> has to be 1.
>
> Puthikorn: We will drop the DP_EDP_BACKLIGHT_PIN_ENABLE_CAP != 0 check
> in next patch set.
> This patch adds check here to prepare for that.
>
>
> 1) So, this patch does not really fix what the commit message claims
> because it is dependent on the following patch. Does it make sense to
> remove this check in this patch? That way, this patch by itself is the
> fix that the commit message says.
>
> - !((intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_PIN_ENABLE_CAP)
>
Sure. I can remove this here and adds it in next patch instead.
>
> 2) If a panel supports backlight enable via AUX and BL_ENABLE pin, this
> patch (along with the next) enables backlight twice, doesn't it?
> _intel_edp_backlight_on(intel_dp) in intel_dp.c is called
> unconditionally after intel_dp_aux_enable_backlight(). I don't know how
> likely this configuration is or if it's alright to enable via both AUX
> and BL_ENABLE pin.
>
The eDP spec did not mention this case explicitly.
But it should not hurt to enable backlight twice as we want the backlight to be enabled anyway.
>
>
>
>> Signed-off-by: Puthikorn Voravootivat <puthik@xxxxxxxxxxxx>
>> ---
>> drivers/gpu/drm/i915/intel_dp_aux_backlight.c | 5 ++++-
>> 1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/intel_ dp_aux_backlight.c
>> index 870c03fc0f3a..c22712762957 100644
>> --- a/drivers/gpu/drm/i915/intel_dp_aux_backlight.c
>> +++ b/drivers/gpu/drm/i915/intel_dp_aux_backlight.c
>> @@ -28,6 +28,10 @@ static void set_aux_backlight_enable(struct intel_dp *intel_dp, bool enable)
>> {
>> uint8_t reg_val = 0;
>>
>> + /* Early return when display use other mechanism to enable backlight. */
>> + 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) {
>> DRM_DEBUG_KMS("Failed to read DPCD register 0x%x\n",
>> @@ -164,7 +168,6 @@ intel_dp_aux_display_control_capable(struct intel_connector *connector)
>> * the panel can support backlight control over the aux channel
>> */
>> if (intel_dp->edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP &&
>> - (intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP) &&
>> (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP) &&
>> !((intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_PIN_ENABLE_CAP) ||
>> (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP))) {
>
--
Jani Nikula, Intel Open Source Technology Center
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