On 04/08/2014 08:36 AM, Andrzej Hajda wrote:
>
> Hi Denis,
Hi,
>> +#define DRM_MODE_FLAG_POL_PIXDATA_NEGEDGE BIT(1)
>> +#define DRM_MODE_FLAG_POL_PIXDATA_POSEDGE BIT(2)
>> +#define DRM_MODE_FLAG_POL_PIXDATA_PRESERVE BIT(3)
>
> What is the purpose of DRM_MODE_FLAG_POL_PIXDATA_PRESERVE?
> If 'preserve' means 'ignore' we can set to zero negedge and posedge bits
> instead of adding new bit. If it is something different please describe it.
Yes, it meant 'ignore'.
The goal was to be able to have a way to keep the old behavior while
still being able to set the flags.
So, with the imx-drm driver, if none of the DRM_MODE_FLAG_POL_PIXDATA
were set(that is POSEDGE, NEGEDGE, PRESERVE), then in ipuv3-crtc.c, it
went using the old flags settings that were previously hardcoded.
The same applied for DRM_MODE_FLAG_POL_DE.
The patch using theses flags is the 08/12 of this same serie.
>> struct drm_display_mode {
[..]
>> + unsigned int pol_flags;
>
> Adding field and macros description to the DocBook would be nice.
So I will have to describe it in the "Connector Helper Operations"
section of drm.tmpl, right before the mode_valid synopsis ?
Denis.
