From: Jani Nikula <jani.nikula@linux.intel.com>
To: Damien Lespiau <damien.lespiau@intel.com>,
"Sharma, Shashank" <shashank.sharma@intel.com>
Cc: "intel-gfx@lists.freedesktop.org" <intel-gfx@lists.freedesktop.org>
Subject: Re: HDMI 4k modes VIC
Date: Wed, 28 Oct 2015 18:38:21 +0200 [thread overview]
Message-ID: <87h9lb3q4i.fsf@intel.com> (raw)
In-Reply-To: <20151028143037.GB18068@strange.ger.corp.intel.com>
On Wed, 28 Oct 2015, Damien Lespiau <damien.lespiau@intel.com> wrote:
> On Wed, Oct 28, 2015 at 01:58:55PM +0000, Sharma, Shashank wrote:
>> Hi Damien
>>
>> This is regarding one of the patches:
>> drm: Add support for alternate clocks of 4k modes
>> (3f2f653378112c1453c0d83c81746a9225e4bc75)
>>
>> I am seeing that from function drm_match_hdmi_mode we are not returning
>> correct VIC's for 4k modes (listed in edid_4k_modes[])
>> Looks like we are returning VIC=(1, 2, 3, 4) for 4K modes (3840x2160@30Hz,
>> 3840x2160@25Hz, 3840x2160@24Hz and 4096x2160@24Hz)
>
> drm_match_hdmi_mode() doesn't return the VIC for the AVI infoframe, but
> the VIC for the HDMI vendor specific infoframe. See section 8.2.3 of the
> HDMI 1.4 spec.
>
>> But as per the CEA-861-F specs, the respective VIC should be (95, 94 and
>> 93). The VIC returned is being used for writing AVI IF in
>> drm_hdmi_vendor_infoframe_from_display_mode.
>
> That's not the AVI infoframe, that's the HDMI vendor specific infoframe.
>
>> Please help me to understand if there any specific reason for this, or am
>> I missing something in interpretation ?
>
> Are you seeing a bug? it's totally possible, I've never used an actual
> conformance tool when I wrote that code, so it's likely buggy and the
> VIC in the AVI infoframe may well be wrong.
Possibly relevant
https://bugs.freedesktop.org/show_bug.cgi?id=92217
>
> --
> Damien
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
--
Jani Nikula, Intel Open Source Technology Center
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next prev parent reply other threads:[~2015-10-28 16:38 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-28 13:58 HDMI 4k modes VIC Sharma, Shashank
2015-10-28 14:30 ` Damien Lespiau
2015-10-28 16:38 ` Jani Nikula [this message]
2015-10-28 16:50 ` Damien Lespiau
2015-10-29 8:03 ` Sharma, Shashank
2015-10-29 13:18 ` [Intel-gfx] " Ville Syrjälä
2015-10-29 15:06 ` Sharma, Shashank
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