Alan Mackenzie wrote: > Hello, Michael. > > On Sat, Aug 24, 2024 at 20:36:11 +0000, Alan Mackenzie wrote: >> On Sat, Aug 24, 2024 at 16:40:38 +0100, Michael wrote: >>> On Saturday, 24 August 2024 14:25:31 BST Alan Mackenzie wrote: >>>> On Sat, Aug 24, 2024 at 10:44:44 +0100, Michael wrote: > [ .... ] > >>> This reads like an unsuitable refresh rate problem. >> I've read the "information" section from my monitor's adjustment panel. >> It says 60 Hz. and 1920x1080 (on my current machine). On the new >> machine, it reads 60 Hz., 2112x1016. This looks like being at the core >> of the problem. 2112 / 1920 = 1.1 (more or less), i.e. 10% too many >> pixels. >> My monitor is ~52cm wide. 10% of this is the ~5cm. black strip at the >> LHS of the monitor. >> Is there any convenient way I can display the current EDID information >> block? > Yes, there is: there is the package x11-misc/read-edid, which contains > two utilities get-edid and parse-edid. Calling # get-edid | parse-edid > produces, on my current machine: > > This is read-edid version 3.0.2. Prepare for some fun. > Attempting to use i2c interface > No EDID on bus 0 > No EDID on bus 2 > No EDID on bus 3 > No EDID on bus 4 > No EDID on bus 5 > No EDID on bus 6 > No EDID on bus 7 > 1 potential busses found: 1 > 256-byte EDID successfully retrieved from i2c bus 1 > Looks like i2c was successful. Have a good day. > Checksum Correct > > Section "Monitor" > Identifier "SMB2430L" > ModelName "SMB2430L" > VendorName "SAM" > # Monitor Manufactured week 13 of 2011 > # EDID version 1.3 > # Digital Display > DisplaySize 520 290 > Gamma 2.20 > Option "DPMS" "true" > Horizsync 30-81 > VertRefresh 56-75 > # Maximum pixel clock is 170MHz > #Not giving standard mode: 1280x800, 60Hz > #Not giving standard mode: 1280x960, 60Hz > #Not giving standard mode: 1280x1024, 60Hz > #Not giving standard mode: 1440x900, 60Hz > #Not giving standard mode: 1600x1200, 60Hz > #Not giving standard mode: 1680x1050, 60Hz > #Not giving standard mode: 1152x864, 75Hz > #Not giving standard mode: 1440x900, 75Hz > > #Extension block found. Parsing... > Modeline "Mode 0" +hsync +vsync > Modeline "Mode 1" +hsync +vsync > Modeline "Mode 2" +hsync +vsync > Modeline "Mode 3" +hsync +vsync > Modeline "Mode 4" -hsync -vsync > EndSection > > .. On my new machine, it is almost identical, just using I2C bus 0, > rather than 1. > > It is now clear that EDID contains not an optimal screen setting, but > instead ranges (for example 56-75 Hz. screen refresh rate). The > question arises, what exactly puts the display into 1920x1080 60Hz. at > boot up time? Something must be chosing that resolution. I've tried > grepping the kernel sources, but there are a lot lf "1920x1080"s there. > :-( > > [ .... ] > >> My hypothesis at the moment is that something in the new machine is >> wrongly pumping out 2112x1016 in place of 1980x1080 and this is >> diminishing the size of (and reducing the quality of) the displayed >> image. >> I think the EDID being received from the monitor and KVM-box are correct, >> but that the BIOS is applying some "correction" to them, for some reason. >> Maybe I should try resetting the CMOS ram. >>> Let's hope one of these things delivers a working display for you. :-) >> Thanks!
Just for giggles, I emerged that package and ran that command on my system. All my monitors are running at 1920 x 1080. However, this is my output. root@Gentoo-1 / # get-edid | parse-edid This is read-edid version 3.0.2. Prepare for some fun. Attempting to use i2c interface No EDID on bus 0 No EDID on bus 1 No EDID on bus 2 No EDID on bus 4 No EDID on bus 5 2 potential busses found: 3 6 Will scan through until the first EDID is found. Pass a bus number as an option to this program to go only for that one. 256-byte EDID successfully retrieved from i2c bus 3 Looks like i2c was successful. Have a good day. Checksum Correct Section "Monitor" Identifier "LS32B30" ModelName "LS32B30" VendorName "SAM" # Monitor Manufactured week 13 of 2024 # EDID version 1.3 # Digital Display DisplaySize 160 90 Gamma 2.20 Option "DPMS" "true" Horizsync 30-84 VertRefresh 48-75 # Maximum pixel clock is 180MHz #Not giving standard mode: 1280x720, 60Hz #Not giving standard mode: 1280x800, 60Hz #Not giving standard mode: 1280x1024, 60Hz #Not giving standard mode: 1440x900, 60Hz #Not giving standard mode: 1600x900, 60Hz #Not giving standard mode: 1680x1050, 60Hz #Not giving standard mode: 1152x864, 75Hz #Extension block found. Parsing... Modeline "Mode 7" +hsync +vsync Modeline "Mode 0" +hsync +vsync Modeline "Mode 1" 148.500 1920 2008 2052 2200 1080 1084 1089 1125 +hsync +vsync Modeline "Mode 2" 74.250 1280 1390 1420 1650 720 725 730 750 +hsync +vsync Modeline "Mode 3" 148.500 1920 2448 2492 2640 1080 1084 1089 1125 +hsync +vsync Modeline "Mode 4" 74.250 1280 1720 1760 1980 720 725 730 750 +hsync +vsync Modeline "Mode 5" 27.027 720 736 798 858 480 489 495 525 -hsync -vsync Modeline "Mode 6" 27.000 720 732 796 864 576 581 586 625 -hsync -vsync Modeline "Mode 8" -hsync -vsync Modeline "Mode 9" -hsync -vsync Modeline "Mode 10" +hsync +vsync Option "PreferredMode" "Mode 7" EndSection root@Gentoo-1 / # Even tho my monitor is working fine, no winking in a while now, the resolution it is running at isn't listed either. I might also add, I have three monitors connected but only one is seen by that command. I'm wondering if there is something wonky with that program. I'd expect the resolution it is currently running at to be listed. Given it is not, I'd call that odd. Or wonky. ;-) I might add, there is some differences so it is seeing something. It's not just spitting out the same info no matter what. Odd. Dale :-) :-)
