Dell P2217H EDID issue - Monitor or GPU?

[saboya]

Hi. I recently acquired a Dell P2217H. It has a maximum resolution of 1920x1080@60hz and 3 inputs: VGA, HDMI and DisplayPort.

Over HDMI, it works just fine at 1920x1080 as advertised.
However, over VGA and DP it only display available resolutions up to 1680x1050. To make it work at 1920x1080, I have to add a custom resolution using CRU (or through Nvidia control panel) on Windows.

With the little bit of knowledge I have, I decided to check the monitor's EDID. The problem is that the 1920x1080 resolution is defined in an extension block, and apparently my GPU cannot read the extension block through DP, only using HDMI. I was certain that this was a monitor issue until I read, in the CRU thread, that Nvidia driver has issues with extension blocks. And I only tested the monitor in 2 computers: My desktop (ASUS 1070 GTX) and my laptop (onboard Intel with a GeForce 840M, and I believe the VGA port is connected to the GeForce GPU).

My question is: Is this likely a monitor issue and I should try to have Dell get me a working monitor, or this could just be the Nvidia issue? And why does it work through HDMI but not DP or VGA?

Here's the output of edid-decode of the dump I made through HDMI

Code:

Extracted contents:
header:          00 ff ff ff ff ff ff 00
serial number:   10 ac 99 d0 54 35 42 30 1c 1a
version:         01 03
basic params:    80 2f 1e 78 ea
chroma info:     f1 05 a2 5b 4f a4 27 12 50 54
established:     a5 4b 00
standard:        71 4f 81 80 b3 00 01 01 01 01 01 01 01 01 01 01
descriptor 1:    21 39 90 30 62 1a 27 40 68 b0 36 00 da 28 11 00 00 1c
descriptor 2:    00 00 00 ff 00 36 4b 35 4e 43 36 37 37 30 42 35 54 0a
descriptor 3:    00 00 00 fc 00 44 45 4c 4c 20 50 32 32 31 37 0a 20 20
descriptor 4:    00 00 00 fd 00 38 4c 1e 53 10 00 0a 20 20 20 20 20 20
extensions:      01
checksum:        73

Manufacturer: DEL Model d099 Serial Number 809645396
Made week 28 of 2016
EDID version: 1.3
Digital display
Maximum image size: 47 cm x 30 cm
Gamma: 2.20
DPMS levels: Standby Suspend Off
Supported color formats: RGB 4:4:4, YCrCb 4:4:4
First detailed timing is preferred timing
Established timings supported:
  720x400@70Hz
  640x480@60Hz
  640x480@75Hz
  800x600@60Hz
  800x600@75Hz
  1024x768@60Hz
  1024x768@75Hz
  1280x1024@75Hz
Standard timings supported:
  1152x864@75Hz
  1280x1024@60Hz
  1680x1050@60Hz
Detailed mode: Clock 146.250 MHz, 474 mm x 296 mm
               1680 1784 1960 2240 hborder 0
               1050 1053 1059 1089 vborder 0
               -hsync +vsync
Serial number: 6K5NC6770B5T
Monitor name: DELL
Monitor ranges (GTF): 56-76Hz V, 30-83kHz H, max dotclock 160MHz
Has 1 extension blocks
Checksum: 0x73 (valid)

CEA extension block
Extension version: 3
19 bytes of CEA data
  Video data block
    VIC  16 1920x1080@60Hz (native)
    VIC  31 1920x1080@50Hz
    VIC   1 640x480@60Hz
    VIC   2 720x480@60Hz
    VIC   3 720x480@60Hz
    VIC   7 1440x480i@60Hz
    VIC  18 720x576@50Hz
    VIC  22 1440x576i@50Hz
    VIC   4 1280x720@60Hz
    VIC  19 1280x720@50Hz
    VIC  20 1920x1080i@50Hz
    VIC   5 1920x1080i@60Hz
  Vendor-specific data block, OUI 000c03 (HDMI)
    Source physical address 1.0.0.0
Underscans PC formats by default
Supports YCbCr 4:4:4
Supports YCbCr 4:2:2
1 native detailed modes
Detailed mode: Clock 148.500 MHz, 474 mm x 296 mm
               1920 2008 2052 2200 hborder 0
               1080 1084 1089 1125 vborder 0
               +hsync +vsync
Detailed mode: Clock 74.250 MHz, 474 mm x 296 mm
               1920 2008 2052 2200 hborder 0
                540  542  547  562 vborder 0
               +hsync +vsync interlaced
Detailed mode: Clock 74.250 MHz, 474 mm x 296 mm
               1280 1390 1430 1650 hborder 0
                720  725  730  750 vborder 0
               +hsync +vsync
Detailed mode: Clock 27.000 MHz, 474 mm x 296 mm
                720  736  798  858 hborder 0
                480  489  495  525 vborder 0
               -hsync -vsync
Checksum: 0x51 (valid)

EDID block does NOT conform to EDID 1.3!
    Detailed block string not properly terminated

Thanks in advance

PS: Your nvidia driver patches and CRU saved me many times, thanks a lot for your time and effort.

[ToastyX]

Do you have the P2217 or the P2217H? The P2217 is 1680x1050, while the P2217H is 1920x1080. If you have the P2217H, then it has the wrong EDID. 1920x1080 should be the first detailed resolution, not 1680x1050.

NVIDIA does not have issues reading extension blocks, only overrides with no extension blocks. CRU 1.3 can now read extension blocks with NVIDIA. Does CRU show the monitor has an extension block with DisplayPort? The monitor might not have one.

[saboya]

(11-20-2016 07:28 PM)ToastyX Wrote:  Do you have the P2217 or the P2217H? The P2217 is 1680x1050, while the P2217H is 1920x1080. If you have the P2217H, then it has the wrong EDID. 1920x1080 should be the first detailed resolution, not 1680x1050.

NVIDIA does not have issues reading extension blocks, only overrides with no extension blocks. CRU 1.3 can now read extension blocks with NVIDIA. Does CRU show the monitor has an extension block with DisplayPort? The monitor might not have one.

It's the P2217H. Or at least it should be Pretty sure they took some P2217 skeletons and replaced the panel but messed up reprogramming the EDID. Anyway, the EDID I posted is the EDID I dumped through the HDMI port on Linux, and CRU indentifies the extension block when connected via HDMI:

[Image: http://imgur.com/sS1KBoX]

However, through DisplayPort it does not show up (full hd resolution added by me):

[Image: http://imgur.com/Fawpt2C]

So, Nvidia actually has no problems with this, and the monitor is simply not sending the extension block through DP / VGA ports then?

[saboya]

Well, now that I took I closer look to what I posted, it's pretty obvious:

Code:

CEA extension block
Extension version: 3
19 bytes of CEA data
  Video data block
    VIC  16 1920x1080@60Hz (native)
    VIC  31 1920x1080@50Hz
    VIC   1 640x480@60Hz
    VIC   2 720x480@60Hz
    VIC   3 720x480@60Hz
    VIC   7 1440x480i@60Hz
    VIC  18 720x576@50Hz
    VIC  22 1440x576i@50Hz
    VIC   4 1280x720@60Hz
    VIC  19 1280x720@50Hz
    VIC  20 1920x1080i@50Hz
    VIC   5 1920x1080i@60Hz
  Vendor-specific data block, OUI 000c03 (HDMI) <=== HERE!!!!!
    Source physical address 1.0.0.0

CRU also has (HDMI) at the end of the data block definition. So, it seems the GPU is ignoring the extension block when reading the EDID through VGA or DP since it's a HDMI-specific extension block, reasonably so.

Did I get this right?

[ToastyX]

(11-20-2016 11:23 PM)saboya Wrote:  [Image: http://imgur.com/Fawpt2C]

So, Nvidia actually has no problems with this, and the monitor is simply not sending the extension block through DP / VGA ports then?

That's likely the case. To know for sure, you have to reset it first. CRU will show you if the EDID has extension blocks. "No extension blocks" means the EDID has no extension blocks. "Default extension block" means the EDID has an extension block, but CRU couldn't read it.

(11-21-2016 03:18 AM)saboya Wrote:  CRU also has (HDMI) at the end of the data block definition. So, it seems the GPU is ignoring the extension block when reading the EDID through VGA or DP since it's a HDMI-specific extension block, reasonably so.

Did I get this right?

No, it's not ignoring anything. Each port on the monitor has a separate EDID. HDMI requires an extension block to define HDMI support. DisplayPort and VGA don't need extension blocks, but they can use extension blocks to define more resolutions.

[saboya]

I see. Thanks for clarifying the situation for me. I'll get in touch with Dell to sort this out.