[PATCHv2 0/9] omapdrm: hdmi4: add CEC support

[Tomi Valkeinen]


Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

On 12/10/17 12:42, Hans Verkuil wrote:
> On 10/12/17 10:03, Tomi Valkeinen wrote:
>>
>> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
>>
>> On 12/10/17 09:50, Hans Verkuil wrote:
>>
>>>> I can't test with a TV, so no CEC for me... But otherwise I think the
>>>> series works ok now, and looks ok. So I'll apply, but it's a bit late
>>>> for the next merge window, so I'll aim for 4.15 with this.
>>>
>>> What is the status? Do you need anything from me? I'd like to get this in for 4.15.
>>
>> Thanks for reminding. I think I would've forgotten...
>>
>> I sent the pull request, so all should be fine.
>>
>> If possible, please test the pull request, preferably with drm-next
>> merged (git://people.freedesktop.org/~airlied/linux drm-next), as I
>> don't have a CEC capable display.
> 
> I'll try to do that tomorrow or Monday.
> 
> I have one other question for you: does keeping ls_oe_gpio high all the
> time affect this old bug fix:
> 
> https://github.com/myfluxi/xxICSKernel/commit/21189f03d3ec3a74d9949907c828410d7a9a86d5

No, the issue is about the HDMI PHY. The i2c lines are not related.
LS_OE only affects the i2c.

> I don't think so, but I'm not 100% sure. As far as I can see the PHY power
> sequence (OFF, TXON, LDOON) does not change and that seems to be the
> crucial fix according to the commit above.
> 
> I would hate being responsible for lots of burnt-out pandaboards :-)
> 
> There is an alternative solution: when there is no HPD then it is also
> possible to pull the ls_oe_gpio high only when transmitting a CEC message.
> 
> That would obviously require some code changes.
> 
> Sorry for raising this issue so late, but this just came up today in
> internal discussions.

Well, it would be nice to not have LS_OE enabled all the time. But I'm
not sure how much that really matters. I'm sure it uses some power, but
is that even measurable, I have no idea.

 Tomi