Receiving errors about eMMC (?)

[acasta]

TL;DR:  Ayufans latest eMMC-Mate-image. Strange errors in dmesg. See snippet below. Need help interpreting.

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Hi! After some weeks of using my rock64 as bookshelf decoration, I'm finally starting to tinker with it.

At first, I hit some smaller bumps like using the official Mate image and loosing USB power after login.

Now I'm using ayufans latest eMMC Mate image. Installation to the eMMC module was super unproblematic. First reboot worked fine. Did some basic first login stuff (keyboard-layout, password, ...), and issued a reboot command. System tried to start, but delivered a black screen with a blinking cursor. I let it sit like this for about fifteen minutes ("just let it work. who knows, what's going on inside"), then I did a hard reset. System started to graphical login prompt. Typed in password, login box vanished, and that was it. Again fifteen minutes, this time only with the blue rock64 background. 
I grew a bit concerned, but after another hard reset, the system bootet up and everything was fine. And since this last reset it's been stable and useful: No more freezes, quick boot and login, USB power and ethernet woking fine, all looking bright and shiny. 
 
Then I made the error and issued the dmesg command. You know, just out of curiosity. Not that I could understand what it tells me. Just wanted to see what's going on. 
And there I saw them: Errors. Colored brightly red, lots of errors about mmcblk0.
 
Small snippet of dmesg output:

Code:

[   23.781898] mmcblk0: retrying using single block read
[   23.825835] dwmmc_rockchip ff520000.rksdmmc: Unexpected command timeout, state 3
[   23.991919] mmcblk0: error -115 sending stop command, original cmd response 0x900, card status 0xb00
[   23.991933] mmcblk0: error -110 transferring data, sector 3279888, nr 256, cmd response 0x900, card status 0xb00
[   23.992879] mmcblk0: retrying using single block read
[   24.120340] mmcblk0: error -110 sending stop command, original cmd response 0x900, card status 0x400900
[   24.120355] mmcblk0: retrying because a re-tune was needed
[   24.321852] dwmmc_rockchip ff520000.rksdmmc: Successfully tuned phase to 135
[   24.340830] dwmmc_rockchip ff520000.rksdmmc: Unexpected command timeout, state 3
[   24.506898] mmcblk0: error -115 sending stop command, original cmd response 0x900, card status 0xb00
[   24.506914] mmcblk0: error -110 transferring data, sector 265240, nr 232, cmd response 0x900, card status 0xb00
[   24.507855] mmcblk0: retrying using single block read
[   24.577818] dwmmc_rockchip ff520000.rksdmmc: Unexpected command timeout, state 3
[   24.742932] mmcblk0: error -115 sending stop command, original cmd response 0x900, card status 0xb00
[   24.742947] mmcblk0: error -110 transferring data, sector 10191680, nr 144, cmd response 0x900, card status 0xb00
[   24.743909] mmcblk0: retrying using single block read
[   24.835882] dwmmc_rockchip ff520000.rksdmmc: Unexpected command timeout, state 3
[   24.850620] tty_port_close_start: tty->count = 1 port count = 2.
[   25.001946] mmcblk0: error -110 transferring data, sector 5610720, nr 32, cmd response 0x900, card status 0x0
[   25.002839] mmcblk0: retrying using single block read
[   25.306353] mmcblk0: retrying because a re-tune was needed
[   25.599857] dwmmc_rockchip ff520000.rksdmmc: Successfully tuned phase to 135
[   35.494818] dwmmc_rockchip ff520000.rksdmmc: Unexpected command timeout, state 3
[   35.660947] mmcblk0: error -110 transferring data, sector 8489664, nr 152, cmd response 0x900, card status 0x0
[   35.661864] mmcblk0: retrying using single block read
[   35.707819] dwmmc_rockchip ff520000.rksdmmc: Unexpected command timeout, state 3
[   35.873936] mmcblk0: error -115 sending stop command, original cmd response 0x900, card status 0xb00
[   35.873950] mmcblk0: error -110 transferring data, sector 8486664, nr 224, cmd response 0x900, card status 0xb00
[   35.874895] mmcblk0: retrying using single block read
[   38.238823] dwmmc_rockchip ff520000.rksdmmc: Unexpected command timeout, state 3
[   38.404938] mmcblk0: error -110 transferring data, sector 3006264, nr 256, cmd response 0x900, card status 0x0
[   38.405854] mmcblk0: retrying using single block read
[   38.830921] mmcblk0: retrying because a re-tune was needed
[   39.124857] dwmmc_rockchip ff520000.rksdmmc: Successfully tuned phase to 135
[   39.864829] dwmmc_rockchip ff520000.rksdmmc: Unexpected command timeout, state 3
[   40.030909] mmcblk0: error -115 sending stop command, original cmd response 0x900, card status 0xb00
[   40.030923] mmcblk0: error -110 transferring data, sector 5127832, nr 56, cmd response 0x900, card status 0xb00
[   40.031846] mmcblk0: retrying using single block read

Seeing similar errors after reboot(s) made me really concerned. I tried my google-fu, but with limited success: 

• Googling the "dwmmc [...] Unexpected command timeout [...]" line did not bring up any results.
  
• Googling the "error -115" line also did not yield useful hints (or I did not recognise them as such)
  
• Googling the "error -110" line was to some extent successful:
  

I stumbled across a NXP forum thread discussing a very similar error message. Their accepted answer was that the SD-card was "too fast". I don't know whether this is correct or not, but also their problem description is missing the "error -115". (And I am using the 32GB eMMC module, not an SD-card.)

Whilest playing around with the rock64 and dmesg, I made some further observations: 

• When idling, usually no further errors occur. When doing stuff (opening programs, ...), errors continue.
  
• The amount of errors is random. I even had one completly error-free boot.
  
• In dmesg-output, at ~305 sec runtime, I get three EXT4-fs entries, telling about number of errors since last fsck.
  
• Only the "-110" error is colored red, the "-115" is not. (Maybe less dangerous?)
  

 
To clarify: I have a tiny bit of linux experience, but really tiny. Someone showed me "dmesg", now all I know about errors and logging in Linux is dmesg. I also have a Raspberry Pi, and installed Owncloud on it (by following a tutorial). But that's really where my abilities end. To the most part I have no idea what's going on, it feels like stumbling around in the fog. But I am willing to learn about Linux and Rock64 (even though I really should invest my time in other things right now).

I would be very grateful, if someone could shed some light on these error issues.

-ac

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Side note to board administrators: I could not decide whether to put this thead under "Linux" or under "Hardware", so I ended up in "General Discussion" - just to be on the wrong side either way. Feel free to move this thread around. I am very new to forums (at least as active participant) and I am sorry.