Re: [PATCHv2 09/15] OMAP: DSS2: HDMI: implement detect()

["K, Mythri P" <mythripk@ti.com>]

On Wed, Sep 14, 2011 at 12:44 PM, Tomi Valkeinen <tomi.valkeinen@ti.com> wrote:
> On Wed, 2011-09-14 at 11:04 +0530, K, Mythri P wrote:
>> Hi,
>>
>> On Mon, Sep 12, 2011 at 10:16 PM, Rob Clark <robdclark@gmail.com> wrote:
>> > On Mon, Sep 12, 2011 at 8:24 AM, K, Mythri P <mythripk@ti.com> wrote:
>> >>> +bool ti_hdmi_4xxx_detect(struct hdmi_ip_data *ip_data)
>> >>> +{
>> >>> +       int r;
>> >>> +
>> >>> +       void __iomem *base = hdmi_core_sys_base(ip_data);
>> >>> +
>> >>> +       /* HPD */
>> >>> +       r = REG_GET(base, HDMI_CORE_SYS_SYS_STAT, 1, 1);
>> >>> +
>> >>> +       return r = 1;
>> >>> +}
>> >>> +
>> >> For HPD the probe should also be on the core interrupt first , and the
>> >> detect should be dynamic, ie based on the cable connect and disconnect
>> >> event.So this approach for HPD is not really the way.
>> >> Also that should be based on the GPIO(63) , I am planning to push a
>> >> patch on that shortly.
>> >
>> >
>> > Fwiw, we do still need a dssdrv->detect() function from omapdrm
>> > driver..  if there is another way to implement that function, such as
>> > with a GPIO, that is great.  But somehow or another we need the detect
>> > function.  The implementation can always change later.
>> Yes we still need a detect , but the implementation would be different
>> , from the prior experience with the Hot-plug detection it wad found
>> that the interrupt based way to handle HPD was not the best ,but if
>> this is just to poll the status then it should be fine.
>
> I'm not sure I understood. First you say the implementation should be
> different, but then you say this should be fine. So is this a valid
> implementation for detect() or is there a better way to do it?
>
There is a better way to handle Hot-plug detection and notification..
But depends on what is the purpose of this function, Ideally a detect
would be the case to dynamically detect whether the cable is connected
on not , But all this function does is to see the state of the HPD bit
in core state statically.
So I said if the purpose of this function is only to check for the HPD
state bit it is fine.

Thanks and regards,
Mythri.
>  Tomi
>
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