<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/gpu/drm/drm_edid.c, branch v3.4.2</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>drm: remove unneeded redefinition of DDC_ADDR</title>
<updated>2012-03-21T10:19:53+00:00</updated>
<author>
<name>Matt Turner</name>
<email>mattst88@gmail.com</email>
</author>
<published>2011-09-23T17:18:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ef61d3d8b7e626c7ac0a820fac904d4d73c9c175'/>
<id>ef61d3d8b7e626c7ac0a820fac904d4d73c9c175</id>
<content type='text'>
It's already defined in drm_edid.h.

Signed-off-by: Matt Turner &lt;mattst88@gmail.com&gt;
Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
It's already defined in drm_edid.h.

Signed-off-by: Matt Turner &lt;mattst88@gmail.com&gt;
Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm: allow loading an EDID as firmware to override broken monitor</title>
<updated>2012-03-20T10:09:28+00:00</updated>
<author>
<name>Carsten Emde</name>
<email>C.Emde@osadl.org</email>
</author>
<published>2012-03-18T21:37:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=da0df92b57311aa1b26a2a90599ed16e1e968b90'/>
<id>da0df92b57311aa1b26a2a90599ed16e1e968b90</id>
<content type='text'>
Broken monitors and/or broken graphic boards may send erroneous or no
EDID data. This also applies to broken KVM devices that are unable to
correctly forward the EDID data of the connected monitor but invent
their own fantasy data.

This patch allows to specify an EDID data set to be used instead of
probing the monitor for it. It contains built-in data sets of frequently
used screen resolutions. In addition, a particular EDID data set may be
provided in the /lib/firmware directory and loaded via the firmware
interface. The name is passed to the kernel as module parameter of the
drm_kms_helper module either when loaded
  options drm_kms_helper edid_firmware=edid/1280x1024.bin
or as kernel commandline parameter
  drm_kms_helper.edid_firmware=edid/1280x1024.bin

It is also possible to restrict the usage of a specified EDID data set
to a particular connector. This is done by prepending the name of the
connector to the name of the EDID data set using the syntax
  edid_firmware=[&lt;connector&gt;:]&lt;edid&gt;
such as, for example,
  edid_firmware=DVI-I-1:edid/1920x1080.bin
in which case no other connector will be affected.

The built-in data sets are
Resolution    Name
--------------------------------
1024x768      edid/1024x768.bin
1280x1024     edid/1280x1024.bin
1680x1050     edid/1680x1050.bin
1920x1080     edid/1920x1080.bin

They are ignored, if a file with the same name is available in the
/lib/firmware directory.

The built-in EDID data sets are based on standard timings that may not
apply to a particular monitor and even crash it. Ideally, EDID data of
the connected monitor should be used. They may be obtained through the
drm/cardX/cardX-&lt;connector&gt;/edid entry in the /sys/devices PCI directory
of a correctly working graphics adapter.

It is even possible to specify the name of an EDID data set on-the-fly
via the /sys/module interface, e.g.
echo edid/myedid.bin &gt;/sys/module/drm_kms_helper/parameters/edid_firmware
The new screen mode is considered when the related kernel function is
called for the first time after the change. Such calls are made when the
X server is started or when the display settings dialog is opened in an
already running X server.

Signed-off-by: Carsten Emde &lt;C.Emde@osadl.org&gt;
Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Broken monitors and/or broken graphic boards may send erroneous or no
EDID data. This also applies to broken KVM devices that are unable to
correctly forward the EDID data of the connected monitor but invent
their own fantasy data.

This patch allows to specify an EDID data set to be used instead of
probing the monitor for it. It contains built-in data sets of frequently
used screen resolutions. In addition, a particular EDID data set may be
provided in the /lib/firmware directory and loaded via the firmware
interface. The name is passed to the kernel as module parameter of the
drm_kms_helper module either when loaded
  options drm_kms_helper edid_firmware=edid/1280x1024.bin
or as kernel commandline parameter
  drm_kms_helper.edid_firmware=edid/1280x1024.bin

It is also possible to restrict the usage of a specified EDID data set
to a particular connector. This is done by prepending the name of the
connector to the name of the EDID data set using the syntax
  edid_firmware=[&lt;connector&gt;:]&lt;edid&gt;
such as, for example,
  edid_firmware=DVI-I-1:edid/1920x1080.bin
in which case no other connector will be affected.

The built-in data sets are
Resolution    Name
--------------------------------
1024x768      edid/1024x768.bin
1280x1024     edid/1280x1024.bin
1680x1050     edid/1680x1050.bin
1920x1080     edid/1920x1080.bin

They are ignored, if a file with the same name is available in the
/lib/firmware directory.

The built-in EDID data sets are based on standard timings that may not
apply to a particular monitor and even crash it. Ideally, EDID data of
the connected monitor should be used. They may be obtained through the
drm/cardX/cardX-&lt;connector&gt;/edid entry in the /sys/devices PCI directory
of a correctly working graphics adapter.

It is even possible to specify the name of an EDID data set on-the-fly
via the /sys/module interface, e.g.
echo edid/myedid.bin &gt;/sys/module/drm_kms_helper/parameters/edid_firmware
The new screen mode is considered when the related kernel function is
called for the first time after the change. Such calls are made when the
X server is started or when the display settings dialog is opened in an
already running X server.

Signed-off-by: Carsten Emde &lt;C.Emde@osadl.org&gt;
Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/edid: drm modes have to be free with drm_mode_destroy</title>
<updated>2012-02-03T09:50:08+00:00</updated>
<author>
<name>Sascha Hauer</name>
<email>s.hauer@pengutronix.de</email>
</author>
<published>2012-02-01T10:38:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=aefd330e694d5b7b9657cc53821c7879b14c8128'/>
<id>aefd330e694d5b7b9657cc53821c7879b14c8128</id>
<content type='text'>
to add the missing drm_mode_object_put for that mode.

Signed-off-by: Sascha Hauer &lt;s.hauer@pengutronix.de&gt;
Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
to add the missing drm_mode_object_put for that mode.

Signed-off-by: Sascha Hauer &lt;s.hauer@pengutronix.de&gt;
Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm: give up on edid retries when i2c bus is not responding</title>
<updated>2012-02-03T09:38:52+00:00</updated>
<author>
<name>Eugeni Dodonov</name>
<email>eugeni.dodonov@intel.com</email>
</author>
<published>2012-01-05T11:34:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=9292f37e1f5c79400254dca46f83313488093825'/>
<id>9292f37e1f5c79400254dca46f83313488093825</id>
<content type='text'>
This allows to avoid talking to a non-responding bus repeatedly until we
finally timeout after 15 attempts. We can do this by catching the -ENXIO
error, provided by i2c_algo_bit:bit_doAddress call.

Within the bit_doAddress we already try 3 times to get the edid data, so
if the routine tells us that bus is not responding, it is mostly pointless
to keep re-trying those attempts over and over again until we reach final
number of retries.

This change should fix https://bugs.freedesktop.org/show_bug.cgi?id=41059
and improve overall edid detection timing by 10-30% in most cases, and by
a much larger margin in case of phantom outputs (up to 30x in one worst
case).

Timing results for i915-powered machines for 'time xrandr' command:
Machine 1: from 0.840s to 0.290s
Machine 2: from 0.315s to 0.280s
Machine 3: from +/- 4s to 0.184s

Timing results for HD5770 with 'time xrandr' command:
Machine 4: from 3.210s to 1.060s

Reviewed-by: Chris Wilson &lt;chris@hchris-wilson.co.uk&gt;
Reviewed-by: Keith Packard &lt;keithp@keithp.com&gt;
Tested-by: Sean Finney &lt;seanius@seanius.net&gt;
Tested-by: Soren Hansen &lt;soren@linux2go.dk&gt;
Tested-by: Hernando Torque &lt;sirius@sonnenkinder.org&gt;
Tested-by: Mike Lothian &lt;mike@fireburn.co.uk&gt;
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=41059
Signed-off-by: Eugeni Dodonov &lt;eugeni.dodonov@intel.com&gt;
Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This allows to avoid talking to a non-responding bus repeatedly until we
finally timeout after 15 attempts. We can do this by catching the -ENXIO
error, provided by i2c_algo_bit:bit_doAddress call.

Within the bit_doAddress we already try 3 times to get the edid data, so
if the routine tells us that bus is not responding, it is mostly pointless
to keep re-trying those attempts over and over again until we reach final
number of retries.

This change should fix https://bugs.freedesktop.org/show_bug.cgi?id=41059
and improve overall edid detection timing by 10-30% in most cases, and by
a much larger margin in case of phantom outputs (up to 30x in one worst
case).

Timing results for i915-powered machines for 'time xrandr' command:
Machine 1: from 0.840s to 0.290s
Machine 2: from 0.315s to 0.280s
Machine 3: from +/- 4s to 0.184s

Timing results for HD5770 with 'time xrandr' command:
Machine 4: from 3.210s to 1.060s

Reviewed-by: Chris Wilson &lt;chris@hchris-wilson.co.uk&gt;
Reviewed-by: Keith Packard &lt;keithp@keithp.com&gt;
Tested-by: Sean Finney &lt;seanius@seanius.net&gt;
Tested-by: Soren Hansen &lt;soren@linux2go.dk&gt;
Tested-by: Hernando Torque &lt;sirius@sonnenkinder.org&gt;
Tested-by: Mike Lothian &lt;mike@fireburn.co.uk&gt;
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=41059
Signed-off-by: Eugeni Dodonov &lt;eugeni.dodonov@intel.com&gt;
Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Fix wrong assumptions in cea_for_each_detailed_block v2</title>
<updated>2011-12-20T09:51:10+00:00</updated>
<author>
<name>Christian Schmidt</name>
<email>schmidt@digadd.de</email>
</author>
<published>2011-12-19T19:03:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4966b2a9351500cf36f424dfe7a683036fce5622'/>
<id>4966b2a9351500cf36f424dfe7a683036fce5622</id>
<content type='text'>
The current logic misunderstands the spec about CEA 18byte descriptors.
First, the spec doesn't state "detailed timing descriptors" but "18 byte
descriptors", so any data record could be stored, mixed timings and
other data, just as in the standard EDID.
Second, the lower four bit of byte 3 of the CEA record do not contain
the number of descriptors, but "the total number of DTDs defining native
formats in the whole EDID [...], starting with the first DTD in the DTD
list (which starts in the base EDID block)." A device can of course
support non-native formats.

As such the number can't be used to determine n, and the existing code
will filter non-timing 18byte descriptors anyway.

Signed-off-by: Christian Schmidt &lt;schmidt@digadd.de&gt;
Reviewed-by: Adam Jackson &lt;ajax@redhat.com&gt;
Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The current logic misunderstands the spec about CEA 18byte descriptors.
First, the spec doesn't state "detailed timing descriptors" but "18 byte
descriptors", so any data record could be stored, mixed timings and
other data, just as in the standard EDID.
Second, the lower four bit of byte 3 of the CEA record do not contain
the number of descriptors, but "the total number of DTDs defining native
formats in the whole EDID [...], starting with the first DTD in the DTD
list (which starts in the base EDID block)." A device can of course
support non-native formats.

As such the number can't be used to determine n, and the existing code
will filter non-timing 18byte descriptors anyway.

Signed-off-by: Christian Schmidt &lt;schmidt@digadd.de&gt;
Reviewed-by: Adam Jackson &lt;ajax@redhat.com&gt;
Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm_edid_to_eld: check for CEA data blocks only from structure revision 3 on</title>
<updated>2011-12-20T09:51:06+00:00</updated>
<author>
<name>Christian Schmidt</name>
<email>schmidt@digadd.de</email>
</author>
<published>2011-12-19T19:03:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a0ab734d62ef4c35ffa5e39f9ec1e6d6284f05fa'/>
<id>a0ab734d62ef4c35ffa5e39f9ec1e6d6284f05fa</id>
<content type='text'>
CEA datablocks are only defined from revision 3 onwards. Only check for
them if the revision says so.

Signed-of-by: Christian Schmidt &lt;schmidt@digadd.de&gt;
Tested-by: James Cloos &lt;cloos@jhcloos.com&gt;

Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
CEA datablocks are only defined from revision 3 onwards. Only check for
them if the revision says so.

Signed-of-by: Christian Schmidt &lt;schmidt@digadd.de&gt;
Tested-by: James Cloos &lt;cloos@jhcloos.com&gt;

Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/edid: support CEA video modes.</title>
<updated>2011-12-19T14:53:16+00:00</updated>
<author>
<name>Christian Schmidt</name>
<email>schmidt@digadd.de</email>
</author>
<published>2011-12-19T14:53:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=54ac76f851a1789b047b74a8e14980f2dd1ac749'/>
<id>54ac76f851a1789b047b74a8e14980f2dd1ac749</id>
<content type='text'>
TFT/plasma televisions and projectors have become commonplace, and so
has the use of PCs to drive them. Add the video modes specified by an
EDID's CEA extension to the mode database for a connector.

Before:
[    1.158869] [drm:drm_mode_debug_printmodeline], Modeline
19:"1920x1080i" 0 74250 1920 2448 2492 2640 1080 1084 1094 1125 0x40 0x15
[    1.158875] [drm:drm_mode_debug_printmodeline], Modeline
18:"1920x1080i" 0 74250 1920 2008 2052 2200 1080 1084 1094 1125 0x48 0x15
[    1.158882] [drm:drm_mode_debug_printmodeline], Modeline
20:"1920x1080" 24 74250 1920 2558 2602 2750 1080 1084 1089 1125 0x40 0x5

After:
[    1.144175] [drm:drm_mode_debug_printmodeline], Modeline
22:"1920x1080" 0 74250 1920 2448 2492 2640 1080 1084 1094 1125 0x40 0x15
[    1.144179] [drm:drm_mode_debug_printmodeline], Modeline
21:"1920x1080" 0 74250 1920 2008 2052 2200 1080 1084 1094 1125 0x48 0x15
[    1.144187] [drm:drm_mode_debug_printmodeline], Modeline
30:"1920x1080" 50 148500 1920 2448 2492 2640 1080 1084 1089 1125 0x40 0x5
[    1.144190] [drm:drm_mode_debug_printmodeline], Modeline
29:"1920x1080" 60 148500 1920 2008 2052 2200 1080 1084 1089 1125 0x40 0x5
[    1.144192] [drm:drm_mode_debug_printmodeline], Modeline
25:"1920x1080" 24 74250 1920 2558 2602 2750 1080 1084 1089 1125 0x40 0x5
[    1.144195] [drm:drm_mode_debug_printmodeline], Modeline
24:"1280x720" 50 74250 1280 1720 1760 1980 720 725 730 750 0x40 0x5
[    1.144198] [drm:drm_mode_debug_printmodeline], Modeline
23:"1280x720" 60 74250 1280 1390 1430 1650 720 725 730 750 0x40 0x5
[    1.144201] [drm:drm_mode_debug_printmodeline], Modeline 27:"720x576"
50 27000 720 732 796 864 576 581 586 625 0x40 0xa
[    1.144203] [drm:drm_mode_debug_printmodeline], Modeline 26:"720x480"
60 27000 720 736 798 858 480 489 495 525 0x40 0xa
[    1.144206] [drm:drm_mode_debug_printmodeline], Modeline 28:"640x480"
60 25175 640 656 752 800 480 490 492 525 0x40 0xa

Signed-off-by: Christian Schmidt &lt;schmidt@digadd.de&gt;
Reviewed-by: Adam Jackson &lt;ajax@redhat.com&gt;
Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
TFT/plasma televisions and projectors have become commonplace, and so
has the use of PCs to drive them. Add the video modes specified by an
EDID's CEA extension to the mode database for a connector.

Before:
[    1.158869] [drm:drm_mode_debug_printmodeline], Modeline
19:"1920x1080i" 0 74250 1920 2448 2492 2640 1080 1084 1094 1125 0x40 0x15
[    1.158875] [drm:drm_mode_debug_printmodeline], Modeline
18:"1920x1080i" 0 74250 1920 2008 2052 2200 1080 1084 1094 1125 0x48 0x15
[    1.158882] [drm:drm_mode_debug_printmodeline], Modeline
20:"1920x1080" 24 74250 1920 2558 2602 2750 1080 1084 1089 1125 0x40 0x5

After:
[    1.144175] [drm:drm_mode_debug_printmodeline], Modeline
22:"1920x1080" 0 74250 1920 2448 2492 2640 1080 1084 1094 1125 0x40 0x15
[    1.144179] [drm:drm_mode_debug_printmodeline], Modeline
21:"1920x1080" 0 74250 1920 2008 2052 2200 1080 1084 1094 1125 0x48 0x15
[    1.144187] [drm:drm_mode_debug_printmodeline], Modeline
30:"1920x1080" 50 148500 1920 2448 2492 2640 1080 1084 1089 1125 0x40 0x5
[    1.144190] [drm:drm_mode_debug_printmodeline], Modeline
29:"1920x1080" 60 148500 1920 2008 2052 2200 1080 1084 1089 1125 0x40 0x5
[    1.144192] [drm:drm_mode_debug_printmodeline], Modeline
25:"1920x1080" 24 74250 1920 2558 2602 2750 1080 1084 1089 1125 0x40 0x5
[    1.144195] [drm:drm_mode_debug_printmodeline], Modeline
24:"1280x720" 50 74250 1280 1720 1760 1980 720 725 730 750 0x40 0x5
[    1.144198] [drm:drm_mode_debug_printmodeline], Modeline
23:"1280x720" 60 74250 1280 1390 1430 1650 720 725 730 750 0x40 0x5
[    1.144201] [drm:drm_mode_debug_printmodeline], Modeline 27:"720x576"
50 27000 720 732 796 864 576 581 586 625 0x40 0xa
[    1.144203] [drm:drm_mode_debug_printmodeline], Modeline 26:"720x480"
60 27000 720 736 798 858 480 489 495 525 0x40 0xa
[    1.144206] [drm:drm_mode_debug_printmodeline], Modeline 28:"640x480"
60 25175 640 656 752 800 480 490 492 525 0x40 0xa

Signed-off-by: Christian Schmidt &lt;schmidt@digadd.de&gt;
Reviewed-by: Adam Jackson &lt;ajax@redhat.com&gt;
Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>gpu: Add export.h as required to drivers/gpu files.</title>
<updated>2011-10-31T23:32:03+00:00</updated>
<author>
<name>Paul Gortmaker</name>
<email>paul.gortmaker@windriver.com</email>
</author>
<published>2011-08-30T22:16:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2d1a8a48ac68a835c42d8a31a02b8158cd599615'/>
<id>2d1a8a48ac68a835c42d8a31a02b8158cd599615</id>
<content type='text'>
They need this to get all the EXPORT_SYMBOL variants and THIS_MODULE

Signed-off-by: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
They need this to get all the EXPORT_SYMBOL variants and THIS_MODULE

Signed-off-by: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm: support routines for HDMI/DP ELD</title>
<updated>2011-09-21T21:52:41+00:00</updated>
<author>
<name>Wu Fengguang</name>
<email>fengguang.wu@intel.com</email>
</author>
<published>2011-09-05T06:23:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=76adaa34db407f174dd06370cb60f6029c33b465'/>
<id>76adaa34db407f174dd06370cb60f6029c33b465</id>
<content type='text'>
ELD (EDID-Like Data) describes to the HDMI/DP audio driver the audio
capabilities of the plugged monitor.

This adds drm_edid_to_eld() for converting EDID to ELD. The converted
ELD will be saved in a new drm_connector.eld[128] data field. This is
necessary because the graphics driver will need to fixup some of the
data fields (eg. HDMI/DP connection type, AV sync delay) before writing
to the hardware ELD buffer. drm_av_sync_delay() will help the graphics
drivers dynamically compute the AV sync delay for fixing-up the ELD.

ELD selection policy: it's possible for one encoder to be associated
with multiple connectors (ie. monitors), in which case the first found
ELD will be returned by drm_select_eld(). This policy may not be
suitable for all users, but let's start it simple first.

The impact of ELD selection policy: assume there are two monitors, one
supports stereo playback and the other has 8-channel output; cloned
display mode is used, so that the two monitors are associated with the
same internal encoder. If only the stereo playback capability is reported,
the user won't be able to start 8-channel playback; if the 8-channel ELD
is reported, then user space applications may send 8-channel samples
down, however the user may actually be listening to the 2-channel
monitor and not connecting speakers to the 8-channel monitor.

According to James, many TVs will either refuse the display anything or
pop-up an OSD warning whenever they receive hdmi audio which they cannot
handle. Eventually we will require configurability and/or per-monitor
audio control even when the video is cloned.

CC: Zhao Yakui &lt;yakui.zhao@intel.com&gt;
CC: Wang Zhenyu &lt;zhenyu.z.wang@intel.com&gt;
CC: Jeremy Bush &lt;contractfrombelow@gmail.com&gt;
CC: Christopher White &lt;c.white@pulseforce.com&gt;
CC: Pierre-Louis Bossart &lt;pierre-louis.bossart@intel.com&gt;
CC: Paul Menzel &lt;paulepanter@users.sourceforge.net&gt;
CC: James Cloos &lt;cloos@jhcloos.com&gt;
CC: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Signed-off-by: Ben Skeggs &lt;bskeggs@redhat.com&gt;
Signed-off-by: Wu Fengguang &lt;fengguang.wu@intel.com&gt;
Signed-off-by: Keith Packard &lt;keithp@keithp.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
ELD (EDID-Like Data) describes to the HDMI/DP audio driver the audio
capabilities of the plugged monitor.

This adds drm_edid_to_eld() for converting EDID to ELD. The converted
ELD will be saved in a new drm_connector.eld[128] data field. This is
necessary because the graphics driver will need to fixup some of the
data fields (eg. HDMI/DP connection type, AV sync delay) before writing
to the hardware ELD buffer. drm_av_sync_delay() will help the graphics
drivers dynamically compute the AV sync delay for fixing-up the ELD.

ELD selection policy: it's possible for one encoder to be associated
with multiple connectors (ie. monitors), in which case the first found
ELD will be returned by drm_select_eld(). This policy may not be
suitable for all users, but let's start it simple first.

The impact of ELD selection policy: assume there are two monitors, one
supports stereo playback and the other has 8-channel output; cloned
display mode is used, so that the two monitors are associated with the
same internal encoder. If only the stereo playback capability is reported,
the user won't be able to start 8-channel playback; if the 8-channel ELD
is reported, then user space applications may send 8-channel samples
down, however the user may actually be listening to the 2-channel
monitor and not connecting speakers to the 8-channel monitor.

According to James, many TVs will either refuse the display anything or
pop-up an OSD warning whenever they receive hdmi audio which they cannot
handle. Eventually we will require configurability and/or per-monitor
audio control even when the video is cloned.

CC: Zhao Yakui &lt;yakui.zhao@intel.com&gt;
CC: Wang Zhenyu &lt;zhenyu.z.wang@intel.com&gt;
CC: Jeremy Bush &lt;contractfrombelow@gmail.com&gt;
CC: Christopher White &lt;c.white@pulseforce.com&gt;
CC: Pierre-Louis Bossart &lt;pierre-louis.bossart@intel.com&gt;
CC: Paul Menzel &lt;paulepanter@users.sourceforge.net&gt;
CC: James Cloos &lt;cloos@jhcloos.com&gt;
CC: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Signed-off-by: Ben Skeggs &lt;bskeggs@redhat.com&gt;
Signed-off-by: Wu Fengguang &lt;fengguang.wu@intel.com&gt;
Signed-off-by: Keith Packard &lt;keithp@keithp.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm: Separate EDID Header Check from EDID Block Check</title>
<updated>2011-08-04T13:39:35+00:00</updated>
<author>
<name>Thomas Reim</name>
<email>reimth@gmail.com</email>
</author>
<published>2011-07-29T14:28:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=051963d4832ed61e5ae74f5330b0a94489e101b9'/>
<id>051963d4832ed61e5ae74f5330b0a94489e101b9</id>
<content type='text'>
    Provides function drm_edid_header_is_valid() for EDID header check
    and replaces EDID header check part of function drm_edid_block_valid()
    by a call of drm_edid_header_is_valid().
    This is a prerequisite to extend DDC probing, e. g. in function
    radeon_ddc_probe() for Radeon devices, by a central EDID header check.

    Tested for kernel 2.6.35, 2.6.38 and 3.0

Cc: &lt;stable@kernel.org&gt;
Signed-off-by: Thomas Reim &lt;reimth@gmail.com&gt;
Reviewed-by: Alex Deucher &lt;alexdeucher@gmail.com&gt;
Acked-by: Stephen Michaels &lt;Stephen.Micheals@gmail.com&gt;
Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
    Provides function drm_edid_header_is_valid() for EDID header check
    and replaces EDID header check part of function drm_edid_block_valid()
    by a call of drm_edid_header_is_valid().
    This is a prerequisite to extend DDC probing, e. g. in function
    radeon_ddc_probe() for Radeon devices, by a central EDID header check.

    Tested for kernel 2.6.35, 2.6.38 and 3.0

Cc: &lt;stable@kernel.org&gt;
Signed-off-by: Thomas Reim &lt;reimth@gmail.com&gt;
Reviewed-by: Alex Deucher &lt;alexdeucher@gmail.com&gt;
Acked-by: Stephen Michaels &lt;Stephen.Micheals@gmail.com&gt;
Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
