| 01:14 | flips | I think you would have to fetch the 3.14-sr kernel from solid run's website and manually install there for uboot, but I don't know ... used to be a nice wiki |
| 12:09 | topi` | jnettlet: do you know the ins and outs of HDMI and EDID interfaces? |
| 12:10 | jnettlet | topi`, pretty much yeah. |
| 12:10 | topi` | jnettlet: we have a very strange project where we're feeding a custom hw with HDMI data but it goes thru a HDMI-DVI cable |
| 12:10 | jnettlet | yep |
| 12:11 | topi` | and the company who provides the hw (it's designed to run a bunch of weird displays) says they cannot get any picture |
| 12:11 | topi` | makes me think that the kernel doesn't like the EDID response from their hw or then the resp is ivnalid |
| 12:11 | topi` | invalid |
| 12:11 | topi` | what do things like "nomodeset" do in an ARM kernel= |
| 12:11 | topi` | ? |
| 12:11 | jnettlet | well it will default to 1080p if the edid is false |
| 12:11 | topi` | is it a x86 only thing? |
| 12:11 | topi` | their HW needs a 1024x768 feed |
| 12:12 | topi` | they say it works with their Windows PC ;) |
| 12:12 | jnettlet | it is if you are using the KMS driver which is what it wants |
| 12:12 | topi` | (well of course it works) |
| 12:12 | jnettlet | does u-boot create a picture? That will generate a 1024x768 resolution |
| 12:12 | topi` | I'm wondering if uboot is doing any EDID parsing? |
| 12:13 | jnettlet | it doesn't, just a default 1024x768@60 signal |
| 12:13 | topi` | and is the kernel totally independent on the settings which UBOOT is doing on the display HW? |
| 12:13 | topi` | OK so uboot's output is fixed :) |
| 12:13 | jnettlet | doesn't pay any attention to them. That is why I am curious if u-boot works |
| 12:14 | topi` | maybe their HW rejects the 60hz signal for some reason? |
| 12:14 | jnettlet | you want to look under /sys/class/graphics/fb0/modes && mode in that same directory. That will tell you the modes that were parsed from the edid and what it is trying to use |
| 12:14 | topi` | can this be changed? like, when compiling the kernel with the EDID_FIRMWARE config item, one can give a customized edid/1024x768.bin set |
| 12:14 | topi` | good advice! I'll check that out |
| 12:15 | jnettlet | well they will need to customize it. 1024x768@60Hz is requqired by the HDMI standard which is why we use it. 640x480 or 480p is just too zoomed on most modern displays |
| 12:15 | topi` | we just need to provide remote access to the board... the other company is 100km away :( |
| 12:15 | jnettlet | yeah I understand. You can get all this from a serial console pretty easily. |
| 12:16 | topi` | it's frustrating to work with some old skool HW company, they have no idea of linux, and test everything with their ancient Pentium windows boxes ;) |
| 12:16 | topi` | but they're the only vendor that can provide the "magic box" to enable those legacy displays... |
| 12:16 | jnettlet | you can also change the display mode by taking any of the lines in modes and echo that into mode |
| 12:16 | topi` | oh! |
| 12:16 | topi` | that allows for some experimentation tehn |
| 12:16 | jnettlet | yes |
| 12:17 | jnettlet | you can also use the fbset command to set whatever modeline you want. |
| 12:21 | topi` | what do the prefix chars "S", "V", "D" mean in "modes"? |
| 12:21 | topi` | S:640x480p-60 |
| 12:22 | topi` | "name" says DISP3 BG, how many display controllers are there?? |
| 12:22 | topi` | in i.MX6 |
| 12:23 | topi` | if "state" is 0, does it mean the display is blanked? (probably it is, I'm remotely logged onto the HB that sits at my home) |
| 12:28 | jnettlet | S V D are Standard, Vesa, Detailed |
| 12:28 | jnettlet | up to 3 on the MX6. We have HDMI, LVDS, and parallel |
| 12:29 | topi` | wow |
| 12:29 | topi` | not all 3 can drive high-resolution displays I guess? |
| 12:30 | jnettlet | state is if the port is suspended or not |
| 12:30 | jnettlet | no. HDMI is 1080p, our LVDS is only single channel so up to 1440x900, and parallel is like 720p max I think. |
| 12:30 | jnettlet | maybe 1080p at low refresh |
| 12:30 | topi` | 1440x900 will also work fine in Digital Signage solutions |
| 12:31 | topi` | what we're essentially doing is some very esoteric Digital Signage ;) |
| 12:31 | jnettlet | oh I take that back. We also have the mipi-dsi connector available |
| 12:31 | jnettlet | but you have to choose between that and parallel |
| 12:31 | topi` | DSI sounds familiar. I think we used DSI at Nokia |
| 12:32 | jnettlet | most likely |
| 12:32 | topi` | gotta go eat now :) |
| 12:34 | jnettlet | later |