EDID and KMS

[amphigory]

Thanks! I posted here to see if anyone had a workaround or if my reasoning was unsound. I didn't want to needlessly distract kernel gods from pondering imponderables in the forest of source trees on Mount Olympus.

[agd5f]

Would you recommend an email to kernel dev responsible for EDID quirks? Or is there a mechanism in the works for manual modes specified via kernel parm?

Yes send an email to dri-devel and file a bug on https://bugs.freedesktop.org

[amphigory]

2.6.33-rc7 at the moment. Also (not that it matters for framebuffer) running Debian unstable with Xorg 1.7.4. DRM, Mesa, and xf86-video-ati from master.

This is not a Radeon (RV620) specific issue. It also occurs with NVIDIA cards as well.

I'm using this box for MythTV and X is working fine with tear free Xv. fbcon isn't a big deal for me... just a little annoying when booting or troubleshooting with overscan on console.

Would you recommend an email to kernel dev responsible for EDID quirks? Or is there a mechanism in the works for manual modes specified via kernel parm?

[agd5f]

What kernel are you using kms from?

[amphigory]

Does anyone know if there are plans to allow modesetting from userspace? I have an EDID in Magnavox 1080p HDTV reporting wrong dot clock. I took a look at drm_edid.c in kernel tree but it doesn't look like the quirks addressed there would fix my issue.

Is there anywhere specific to report EDID quirks aside from the dev mailing lists?

X is working fine with custom modeline but fbcon is borked with KMS.

Here is the working X modeline:
"1920x1080@59" 146.0 1920 2008 2052 2200 1080 1084 1089 1125 +hsync +vsync

And here is EDID data reported:

saturn:~# get-edid | parse-edid 
parse-edid: parse-edid version 2.0.0
get-edid: get-edid version 2.0.0

    Performing real mode VBE call
    Interrupt 0x10 ax=0x4f00 bx=0x0 cx=0x0
    Function supported
    Call successful

    VBE version 300
    VBE string at 0xc01d8 "ATI ATOMBIOS"

VBE/DDC service about to be called
    Report DDC capabilities

    Performing real mode VBE call
    Interrupt 0x10 ax=0x4f15 bx=0x0 cx=0x0
    Function supported
    Call successful

    Monitor and video card combination does not support DDC1 transfers
    Monitor and video card combination supports DDC2 transfers
    0 seconds per 128 byte EDID block transfer
    Screen is not blanked during DDC transfer

Reading next EDID block

VBE/DDC service about to be called
    Read EDID

    Performing real mode VBE call
    Interrupt 0x10 ax=0x4f15 bx=0x1 cx=0x0
    Function supported
    Call successful

EDID claims 1 more blocks left


*********** Something special has happened!
Please contact the author, Matthew Kern
E-mail: [email protected]
Please include full output from this program (especially that to stderr)



Reading next EDID block

VBE/DDC service about to be called
    Read EDID

    Performing real mode VBE call
    Interrupt 0x10 ax=0x4f15 bx=0x1 cx=0x0
    Function supported
    Call successful

EDID claims 1 more blocks left
EDID blocks left is wrong.
Your EDID is probably invalid.
parse-edid: EDID checksum passed.

    # EDID version 1 revision 3
Section "Monitor"
    # Block type: 2:0 3:fc
    Identifier "MAGNAVOX TV"
    VendorName "PHL"
    ModelName "MAGNAVOX TV"
    # Block type: 2:0 3:fc
    # Block type: 2:0 3:fd
    HorizSync 30-75
    VertRefresh 56-62
    # Max dot clock (video bandwidth) 160 MHz
    # DPMS capabilities: Active off:no  Suspend:no  Standby:no

    Mode     "1920x1080"    # vfreq 60.000Hz, hfreq 67.500kHz
        DotClock    148.500000
        HTimings    1920 2008 2052 2200
        VTimings    1080 1084 1089 1125
        Flags    "+HSync" "+VSync"
    EndMode
    Mode     "1920x1080"    # vfreq 30.000Hz, hfreq 33.750kHz
        DotClock    74.250000
        HTimings    1920 2008 2052 2200
        VTimings    1080 1084 1089 1125
        Flags    "+HSync" "+VSync"
    EndMode
    # Block type: 2:0 3:fc
    # Block type: 2:0 3:fd
EndSection

Xorg:
(II) RADEON(0): EDID for output HDMI-0
(II) RADEON(0): Manufacturer: PHL  Model: d02a  Serial#: 16843009
(II) RADEON(0): Year: 2007  Week: 14
(II) RADEON(0): EDID Version: 1.3
(II) RADEON(0): Digital Display Input
(II) RADEON(0): Max Image Size [cm]: horiz.: 64  vert.: 36
(II) RADEON(0): Gamma: 2.20
(II) RADEON(0): No DPMS capabilities specified
(II) RADEON(0): Supported color encodings: RGB 4:4:4 YCrCb 4:4:4 
(II) RADEON(0): First detailed timing is preferred mode
(II) RADEON(0): redX: 0.632 redY: 0.324   greenX: 0.273 greenY: 0.591
(II) RADEON(0): blueX: 0.144 blueY: 0.068   whiteX: 0.280 whiteY: 0.285
(II) RADEON(0): Supported established timings:
(II) RADEON(0): 640x480@60Hz
(II) RADEON(0): 800x600@56Hz
(II) RADEON(0): 800x600@60Hz
(II) RADEON(0): 1024x768@60Hz
(II) RADEON(0): Manufacturer's mask: 0
(II) RADEON(0): Supported standard timings:
(II) RADEON(0): #0: hsize: 1280  vsize 1024  refresh: 60  vid: 32897
(II) RADEON(0): Supported detailed timing:
(II) RADEON(0): clock: 148.5 MHz   Image Size:  640 x 360 mm
(II) RADEON(0): h_active: 1920  h_sync: 2008  h_sync_end 2052 h_blank_end 2200 h_border: 0
(II) RADEON(0): v_active: 1080  v_sync: 1084  v_sync_end 1089 v_blanking: 1125 v_border: 0
(II) RADEON(0): Supported detailed timing:
(II) RADEON(0): clock: 74.2 MHz   Image Size:  640 x 360 mm
(II) RADEON(0): h_active: 1920  h_sync: 2008  h_sync_end 2052 h_blank_end 2200 h_border: 0
(II) RADEON(0): v_active: 1080  v_sync: 1084  v_sync_end 1089 v_blanking: 1125 v_border: 0
(II) RADEON(0): Monitor name: MAGNAVOX TV
(II) RADEON(0): Ranges: V min: 56 V max: 62 Hz, H min: 30 H max: 75 kHz, PixClock max 160 MHz
(II) RADEON(0): Number of EDID sections to follow: 1
(II) RADEON(0): EDID (in hex):
(II) RADEON(0):         00ffffffffffff00410c2ad001010101
(II) RADEON(0):         0e110103804024780ac1eca153469724
(II) RADEON(0):         11474923080081800101010101010101
(II) RADEON(0):         010101010101023a801871382d40582c
(II) RADEON(0):         450080682100001e011d801871382d40
(II) RADEON(0):         582c450080682100001e000000fc004d
(II) RADEON(0):         41474e41564f582054560a20000000fd
(II) RADEON(0):         00383e1e4b10000a2020202020200117

Working dot clock is 146.0 but EDID reports 148.5.

Thanks in advance!

[agd5f]

IIRC, you can get the edid info from sysfs. Unfortunately, there is not a lot you can do for the fb console at the moment since the kernel fb interface doesn't support multi-head cards. Right now the console comes up in the preferred mode of the monitor or a supported clone mode if multiple monitors are present.

[duby229]

what about setting the resolution on the kernel line in grub? It seems to only use the max supported by edid?

Also is there a user space utility for reading edid? there used to be one that worked in 32bit mode called read-edid but it doesnt work in 64bit. Is there any plan for something similar that will work with KMS? It would be real nice to be able towrite a script that reads the monitors edid info and then set the resolution before X is even started...

[agd5f]

windows may use cvt to generate the mode. You might try a cvt made rather than gtf. If the mode sync ranges and clock are within the limits of the monitor it should be fine. the adjustments you need to make to your monitor are due to slight differences in the mode timing, probably due to gtf vs cvt.

[bridgman]

IIRC near the front of the log there's a dump of all the available modes with timing info (each mode has a name string plus a list of numbers), then later on there's a couple of cryptic messages telling you which of those modes was selected (via name string).

[MQDuck]

What part of the log should I be looking at? I don't see anything that obviously has to do with timing.