Re: Screen occasionally fails to come on when booting

What gets me is that it used to work fine for me all the time, and now I can never get X to work. Some software update borked things?

Re: Screen occasionally fails to come on when booting

The new SPL isn't installed because it hasn't changed.  Unless there is a major reason to, the SPL will never be automatically installed.  It's similar to how Debian won't update the Grub stage1 automatically.

I wonder if there isn't actually a problem with the chip booting.  You're right, it may make sense to turn the chip off and on again if it isn't responding.

28 (edited by ballanux 2015-05-07 05:46:41)

Re: Screen occasionally fails to come on when booting

Ok, so I finally used a BusPirate to connect to the debug UART on my novena and this is the output I get:

U-Boot SPL 2014.10-rc3-00039-gc5efead (Oct 17 2014 - 19:41:27)
Running post-config memory test... Pass
Internal SD card
reading u-boot.img
reading u-boot.img


U-Boot 2015.04-rc1-02823-g42ae9d5 (Apr 29 2015 - 11:19:31)

CPU:   Freescale i.MX6Q rev1.2 at 792 MHz
Reset cause: POR
Board: Novena 4x
I2C:   ready
DRAM:  3.8 GiB
Can't find PMIC:PFUZE100
initcall sequence fff9c80c failed at call 17801f5d (err=-1)
### ERROR ### Please RESET the board ###

Soo, I may have a faulty power management chip?

Right now I can't boot in any way into my novena, no matter how many times I try...

I checked just to be sure there is not visible damage to the chip or anything, and seems fine:
http://i.imgur.com/MR9DqjD.jpg

Re: Screen occasionally fails to come on when booting

Ok, good news, I'm writing this from my novena smile

I read about the senoko board probably causing I2C problems in this thread:
http://www.kosagi.com/forums/viewtopic.php?id=210
so I tried to boot while pressing the "reflash" button on the senoko board, and it worked!

I would like to re-create the same situation again, but this seems a possible cause

30

Re: Screen occasionally fails to come on when booting

Hmm that looks like the I2C is not responding of the PMIC.
Definitively something different from the occasional screen not coming up.

@xobs: I'm trying to understand the power up of the screen through the dts.

As I'm reading it now, the it6251 is first, referencing the panel, which references the backlight.
The backlight regulator enable (lcd_regulator) is basically just LCD_BL_ON straight to the panel.
The IT6251 regulator enable (display-regulator) is actually turning all power to both IT6251 and LCD on.

Is it correct that only the backlight defines the pinctrl for the enable lines? Could it be too late?
I am not familiar with the startup order of these dts blocks. Or should the mux still be good from u-boot.

31

Re: Screen occasionally fails to come on when booting

job wrote:

Definitively something different from the occasional screen not coming up.

Let me rephrase that :-)

Definitively another way for the occasional screen not coming up.

Re: Screen occasionally fails to come on when booting

ballanux: That definitely seems like Senoko is blocking the I2C smbus.  Everything power-related is on the same bus, so when Senoko barfs things go bad.  There is a new senoko firmware.  Run "sudo apt-get update; sudo apt-get install firmware-senoko; update-senoko" to install it.  It fixes I2C, among other things.

job: That does seem correct.  The pinmux should still be correct.  I find it interesting, though, that the chip sometimes seems to more-or-less crash on startup, where power is applied but it doesn't respond at all.

Re: Screen occasionally fails to come on when booting

This just happened to me again for the first time since switching to the new kernel.

34

Re: Screen occasionally fails to come on when booting

xobs wrote:

I find it interesting, though, that the chip sometimes seems to more-or-less crash on startup, where power is applied but it doesn't respond at all.

The way I read it the chip does not completely crash. I see the messages that the LVDS is not stable in u-boot too, but then it already passed it6251_ready() which seems to indicate there is communication.

But then the status does not get to the desired value.

I now power cycle every 5 retries with 200ms down and 500ms up before continue, but that does not help a thing. It remains stuck. Next reboot sometimes it is ok, sometimes stuck again. I have hardly any of these issues if I'm plugged in. I guess time to get an oscilloscope and see if there is anything to see in the startup power.

Re: Screen occasionally fails to come on when booting

I'm trying out a version of U-Boot and the kernel with DeSSC enabled.

One theory is that the four lanes may be slightly skewed.  I don't see an option to enable SSC in the SoC, but maybe things happen to come out askew sometimes.

My first reboot resulted in a screen that was unstable, at least up until the point at which X started up.  Then the display stabilized, even when throttling the CPU up and down.

The kernel is at https://nas.xobs.io/novena/20150514/ should anyone want to give it a try.

36 (edited by dbtayl 2015-05-15 07:57:14)

Re: Screen occasionally fails to come on when booting

Same problems as before. I see:

-the u-boot "splash screen"

-then get a black screen with full backlight for a while

-then garbled boot text with Tux logo

-then regular ungarbled boot messages

-then a brief flash of X/login manager trying to start

-then black screen, minimal backlight (probably where I left it last)


At this point I can Ctrl+Alt+F# to a different terminal and do stuff there. Unless it involves "ls", in which case the screen goes black (for that VT) until I log out and back in.

This is with the 3.19-r11 kernel and 2014.10-rc17 u-boot.


EDIT: Was there supposed to be a new u-boot to go with the kernel?

EDIT2: Seems like I can get the LCD to (mostly) work if I hold the LVDS<->eDP flex cable in just the right position. Bad connection, maybe? Reseating the cable doesn't seem to help. Flaky cable? EMI issues? (Shielding doesn't seem to help, so probably not).

Re: Screen occasionally fails to come on when booting

This may be a looong shot, but based on dbtayl's comment guessing at cabling/EMI issues... I figured I'd offer that I've seen the LCD blank out briefly when I touch the metal bolt heads on the bezel with the metal of a 30-foot tape measure. (Discovered this while measuring it!) It comes right back and works fine after the ~0.25s glitch. I don't think it's static charge on me and/or the tape measure; I repeated it at a fully-grounded workstation, and with my body and the metal tape bonded to the ethernet metal shell. But *something* is weird, and I can repeat it about 1 out of 3 tries. So in the dim chance it's related, there you go.

38 (edited by dbtayl 2015-06-18 10:46:25)

Re: Screen occasionally fails to come on when booting

Any progress on this front? I haven't had a chance to boot up my Novena and see if the latest test kernels help.

Last I tried, holding the eDP board in a specific position seemed to make things function. Any shielding I put around the cable doesn't seem to help, so I'm not sure it's EMI, and I don't see any sort of mechanical failure (though I wouldn't necessarily). Reseating the ribbon cable didn't seem to help either.

Sorry if this has been solved for everybody else and I just haven't tried the solution yet.

EDIT: Wel, maybe it's OK? I've just tootled around a bit, rebooted a couple times, and all seems well. No magic positioning of the board/cable. Go figure. I don't have the Senoko board in right now, just the passthrough- I hopefully won't be posting back here as soon as I try with the Senoko (which probably won't be right now)...

Re: Screen occasionally fails to come on when booting

There is a set of patches I was sent that might help fix the problem, but I'm without my test machine for another month or so.

Re: Screen occasionally fails to come on when booting

Thanks for everyone's work on this. I can confirm that this still happens.

Boot log:

[   11.148610] it6251 2-005c: System status: 0x3a
[   11.151537] it6251 2-005c: Display didn't stabilize.  This may be because the LVDS port is still in powersave mode.
[   11.154436] it6251 2-005c: Will try again in 400 msecs
[   11.564217] it6251 2-005c: System status: 0x3a
[   11.567112] dummy 2-005e: error -5 writing to lvds addr 0x5
[   11.567118] dummy 2-005e: it6251.c:it6251_init:277 error -1 writing 255 to 5 [   11.974041] it6251 2-005c: System status: 0x3a
[   11.977349] it6251 2-005c: Display didn't stabilize.  This may be because the LVDS port is still in powersave mode.

uname

3.19.0-00270-g3d69696 #654 SMP PREEMPT Mon May 4 13:01:40 SGT 2015 armv7l GNU/Linux

Powercycling does resolve the issue temporarily.

Re: Screen occasionally fails to come on when booting

I'm also having this problem.

I got ``just the board'' and the eDP board, cables, and LCD.  I've checked the assembly several times.

Here is the output from novena-eeprom:

Current EEPROM settings:
        Signature:        Novena
        Version:          2
        Serial:           392
        MAC:              00:1f:11:02:16:87
        Features:         0xf5 (es8328,edp,pcie,gbit,hdmi,eepromoops)
        EEPROM size:      65536
        EEPROM page size: 128
        Oops offset:      4096
        Oops length:      61440
        LVDS channel 1:
                Modeline "lvds1" 4294.967  65535 131070 196605 262140   65535 131070 196605 262140 +HSync +VSync
                Flags: 0xffffffff (channel_present,dual_channel,vsync_polarity,hsync_polarity,mapping_jeida,data_width_8bit,ignore_settings) Unrecognized flags: 0xffffff80
        LVDS channel 2:
                Modeline "lvds2" 4294.967  65535 131070 196605 262140   65535 131070 196605 262140 +HSync +VSync
                Flags: 0xffffffff (channel_present,dual_channel,vsync_polarity,hsync_polarity,mapping_jeida,data_width_8bit,ignore_settings) Unrecognized flags: 0xffffff80
        HDMI channel:
                Modeline "hdmi" 4294.967  65535 131070 196605 262140   65535 131070 196605 262140 -HSync -VSync
                Flags: 0x61 (channel_present,data_width_8bit,ignore_settings)

And here are the relevant lines from the boot log:

[   14.980892] it6251 2-005c: After 200 msec, system status: 0x3a
[   14.980981] it6251 2-005c: Display didn't stabilize.  This may be because the LVDS port is still in powersave mode.
[   14.981093] it6251 2-005c: Will try again in 220 msecs
[   15.195387] dummy 2-005e: error -5 writing to lvds addr 0x5
[   15.564031] it6251 2-005c: After 200 msec, system status: 0x3a
[   15.564151] it6251 2-005c: Display didn't stabilize.  This may be because the LVDS port is still in powersave mode.
[   15.564266] it6251 2-005c: Too many retries, abandoning.
[   97.131500] systemd-journald[140]: Failed to read ACL on /var/log/journal/6984266032cf404495ac5d3a454c757c/user-1000.journal, ignoring: Operation not supported

Re: Screen occasionally fails to come on when booting

Do you see anything on the screen in U-Boot?

The mainboard can talk to the edp board, so there may be a problem between the edp board and the LCD itself.  Check the cabling there.

Re: Screen occasionally fails to come on when booting

Sorry, I just came back to this.  It turns out I had reversed the 56-pin flat cable that connects the eDP board to the main board.  I installed that cable correctly and now the LCD works fine.  Thanks for taking the time to respond.