Hi. I have the same L740 laptop and under Windows XP it report 1366x768 resolution.
Do you know how to get dump of registers under Windows? I would like to VGA or HDMI and check how registers are looks like. Maybe Luc have some experience with dumping registers under Windows. Best Regards Bartosz 2017-03-18 23:37 GMT+01:00 Xavier Bachelot <xav...@bachelot.org>: > Hi Kevin, > > On 18/03/2017 22:32, Kevin Brace wrote: > > Hi Xavier, > > > > Sorry for missing the reply for several days, but I have been > > thinking about this issue for the past few days. > > No worries. > > > I have several possible explanations as to why things are not > > working. Of course, it is not proven so you will need to test it > > yourself. Xavier, since you mentioned pitch, I noticed that when > > reading the Xorg.0.log, I noticed that the screen resolution is 1368 > > x 768. I believe the correct resolution is 1366 x 768. I know that > > sounds strange, but VIA EPIA-M830 user manual lists the panel index, > > and it assigns 1366 x 768 for panel index 10. Yes, 1366 is a number > > that is not dividable by 8, but for some reason, the flat panel > > industry uses this odd resolution for some FPs. > > That doesn't surprise me that much, iirc the (now mostly defunct) > Samsung NC20 I own used 1366x768 too. I'd really need to fix it someday... > > > You might be wondering why this causes the old code which allowed > > IGA1 to work fine with 1366 x 768 flat panel, but not with IGA2. Due > > to the way IBM developed VGA (and probably this goes back to EGA and > > even Motorola MC6845 I suppose), when IGA1 horizontal display period > > is set, the value being set has to be shifted by 3 bit positions (8 > > pixel boundary). IGA1 pretty much drags the original VGA way of > > setting the horizontal display period since it is a superset of VGA, > > but IGA2 is implemented without such restriction since it is a clean > > sheet design. IGA2 horizontal resolution can be set at 1 pixel > > boundary. Since you were using 1368 instead of 1366, this means that > > all other display parameters get messed up like blank period and sync > > period as well. > > Just gave it a try with 1366x768 instead of 1368x768, but that doesn't > help. The screen is still distorted, not the same, but similarly. Also, > the part of the screen displaying a picture is now bigger, it's covering > half the height of the screen, rather than one third with 1368x768. > > > I know that the screen can easily get messed up if these numbers are > > off even slightly, so this might be why you are seeing a distorted > > picture with V2 and V3 patches I sent to you. That being said, you > > said you are seeing a cursor with the V2 and V3 patches that > > previously did not display. > > The only condition I was not sure there was a cursor is when using 0.6.0 > + panel id fix (1368x768) + via_regs_dump -w 3d5.99 0x11 > I just checked and the cursor is there too. > Both v2 and v3 also have the cursor. > Oh, and not sure I mentioned it, the cursor looks fine. it's not > distorted in any way. > > > This probably means that not specifying IGA2 for LVDS1 was one of the > > reason why the screen regression happened, but also 1366 vs. 1368 > > issue came into play, and I also speculate IGA2 itself is far more > > sensitive to the display period being off by even 2 pixels. > > > Let's assume the Epia M830 manual is correct. > I can't get my hands on the manual for this laptop to make sure of the > expected resolution (assuming the manual specify it and is correct > indeed) at the moment, I will need to dig deeper, I'm not even sure > there was one in the first place. Can't find it on the net either, this > is a noname computer, likely a reference design for VIA, who sent it to > me for testing purposes back in the days. > dmidecode says : > Manufacturer: iDOT Computers, Inc. > Product Name: L740 > > Any other idea ? > > Regards, > Xavier > > > > Regards, > > > > Kevin Brace The OpenChrome Project maintainer / developer > > > > > >> Sent: Thursday, March 16, 2017 at 11:17 AM From: "Xavier Bachelot" > >> <xav...@bachelot.org> To: "Kevin Brace" <kevinbr...@gmx.com> Cc: > >> openchrome-devel@lists.freedesktop.org Subject: Re: > >> [Openchrome-devel] openchrome 0.6.0 regressions on VX900 laptop > >> > >> Hi Kevin, > >> > >> On 15/03/2017 23:33, Kevin Brace wrote: > >>> Try this third version of the patch. I changed the FP power on / > >>> off code to use software controlled method already proven with > >>> CX700 / VX700 and VX800 chipsets. > >>> > >> No improvement over patch v2 with patch v3. I haven't collected > >> neither log nor regs dump though. > >> > >> I started to poke at register manually after applying v2 the other > >> day, but no luck. Is there any specific range of registers that are > >> more likely than others to help ? > >> > >> Would a picture of the distorted screen, together with a picture of > >> how it should look like, help ? I don't know how to describe the > >> distortion, a picture is worth a thousand word :-) The display is > >> compressed in the top third or half of the screen, and diagonally > >> stretched to the right. The remaining bottom part of the screen > >> seems like uninitialized memory. It seems like the framebuffer is > >> using a different horizontal resolution than the display. Could it > >> be something like wrong "pitch" ? > >> > >> Regards, Xavier > >> > > _______________________________________________ > Openchrome-devel mailing list > Openchrome-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/openchrome-devel >
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