[Intel-gfx] [PATCH resend 11/15] drm/i915/dsi: Group MIPI_SEQ_BACKLIGHT_ON/OFF with panel_[en|dis]able_backlight

[Hans de Goede]

Hi,

On 27-02-17 18:06, Bob Paauwe wrote:
> On Sat, 25 Feb 2017 11:37:50 +0100
> Hans de Goede <hdegoede at redhat.com> wrote:
>
>> Hi,
>>
>> On 24-02-17 18:00, Bob Paauwe wrote:
>>> On Mon, 20 Feb 2017 15:08:41 +0100
>>> Hans de Goede <hdegoede at redhat.com> wrote:
>>>
>>>> Execute the MIPI_SEQ_BACKLIGHT_ON/OFF VBT sequences at the same time as
>>>> we call intel_panel_enable_backlight() / intel_panel_disable_backlight().
>>>>
>>>> Signed-off-by: Hans de Goede <hdegoede at redhat.com>
>>>
>>> I'm not sure that the added comments are necessary.  Maybe if there was
>>> some explanation for why we're using two different mechanisms to
>>> enable/disable backlight instead.
>>
>> That assumes I know why there are 2 mechanisms of I have to guess it
>> is because on some boards only one of the mechanisms works, but that
>> is just a guess. Just calling the VBT sequence should be enough on
>> (most?) boards.
>>
>> Regards,
>>
>> Hans
>
> I don't think I can describe why we have two mechanisms so just
> dropping the comment would be my preference at this point.

Ok, done for v2 of the patch-set I will go through your other comments
tomorrow and then send a v2.

Regards,

Hans


> It may be that calling the intel_panel_enable_backlight() will make
> sure the sysfs entries are correct while the VBT sequence simply
> modifies the hardware.
>
> Possibly a good solution would be to enhance the code that executes the
> VBT sequence to also call the intel_panel_enable_backlight(), but
> that's not something to change here.
>
>>
>>
>>>
>>> Reviewed-by: Bob Paauwe <bob.j.paauwe at intel.com>
>>>
>>>> ---
>>>>  drivers/gpu/drm/i915/intel_dsi.c | 6 ++++--
>>>>  1 file changed, 4 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c
>>>> index 8408f59..a8d0948 100644
>>>> --- a/drivers/gpu/drm/i915/intel_dsi.c
>>>> +++ b/drivers/gpu/drm/i915/intel_dsi.c
>>>> @@ -687,12 +687,13 @@ static void intel_dsi_pre_enable(struct intel_encoder *encoder,
>>>>  		msleep(100);
>>>>
>>>>  		intel_dsi_exec_vbt_sequence(intel_dsi, MIPI_SEQ_DISPLAY_ON);
>>>> -		intel_dsi_exec_vbt_sequence(intel_dsi, MIPI_SEQ_BACKLIGHT_ON);
>>>>
>>>>  		intel_dsi_port_enable(encoder);
>>>>  	}
>>>>
>>>> +	/* Enable backlight, both pwm and VBT */
>>>>  	intel_panel_enable_backlight() (intel_dsi->attached_connector);
>>>> +	intel_dsi_exec_vbt_sequence(intel_dsi, MIPI_SEQ_BACKLIGHT_ON);
>>>>  }
>>>>
>>>>  static void intel_dsi_enable_nop(struct intel_encoder *encoder,
>>>> @@ -718,6 +719,8 @@ static void intel_dsi_pre_disable(struct intel_encoder *encoder,
>>>>
>>>>  	DRM_DEBUG_KMS("\n");
>>>>
>>>> +	/* Disable backlight, both VBT and pwm */
>>>> +	intel_dsi_exec_vbt_sequence(intel_dsi, MIPI_SEQ_BACKLIGHT_OFF);
>>>>  	intel_panel_disable_backlight(intel_dsi->attached_connector);
>>>>
>>>>  	/*
>>>> @@ -762,7 +765,6 @@ static void intel_dsi_post_disable(struct intel_encoder *encoder,
>>>>  	 * if disable packets are sent before sending shutdown packet then in
>>>>  	 * some next enable sequence send turn on packet error is observed
>>>>  	 */
>>>> -	intel_dsi_exec_vbt_sequence(intel_dsi, MIPI_SEQ_BACKLIGHT_OFF);
>>>>  	intel_dsi_exec_vbt_sequence(intel_dsi, MIPI_SEQ_DISPLAY_OFF);
>>>>
>>>>  	/* Transition to LP-00 */
>>>
>>>
>>>
>
>
>