bugGNU GRUB - Bugs: bug #47406, GRUB2 detects constant addition of...

 
 

You are not allowed to post comments on this tracker with your current authentication level.

bug #47406: GRUB2 detects constant addition of nonexistent USB devices

Submitter:  Timothy Pearson <tpearson>
Submitted:  Mon 14 Mar 2016 05:51:05 AM UTC
   
 
Category:  Booting Severity:  Major
Priority:  6 Item Group:  None
Status:  None Privacy:  Public
Assigned to:  None Originator Name: 
Open/Closed:  Open Release:  Git master
Release:  Reproducibility:  None
Planned Release:  2.02

Mon 28 Mar 2016 10:12:50 PM UTC, comment #5: 

It turns out that the observed symptoms were related to enabling USB debug support in coreboot on the AMD platforms.  Disabling USB debug support resolved the GRUB issues.

I am not sure if this is something that GRUB should detect / handle.  If not please feel free to mark this request invalid.

Thanks!

Timothy Pearson <tpearson>
Wed 16 Mar 2016 03:12:02 AM UTC, comment #4: 

Thank you for the clarification.

Interestingly I am unable to replicate the aforementioned USB problems with a stock coreboot build.  This appears to be specific to Libreboot (a coreboot downstream distribution).  I will update as I have more information.

Timothy Pearson <tpearson>
Tue 15 Mar 2016 05:48:40 PM UTC, comment #3: 

detect_dev is called for every port constantly and its purpose is to detect if new devices are connected and it's lightweight if none is. "Oscilating" is because it actually shows status for different ports. It's piossible that ohci.mod is culprit as it's less tested that ehci for coreboot, hence I ask to remove it from mkrescue command line. Make sure that all connected devices are either USB 2.0 or later or connect through a hub

Vladimir Serbinenko <phcoder>
Group administrator
Mon 14 Mar 2016 08:41:30 PM UTC, comment #2: 

I am not familiar with GRUB's code, however those messages should only be printed if the grub_ohci_detect_dev function is being called repeatedly.  Am I misunderstanding the purpose of that function?

Decoding the flags reveals the status register is changing between:

OHCI_CTRL_IR

and

OHCI_CTRL_CBSR
OHCI_CTRL_IR
OHCI_CTRL_RWC

I am not familiar with the details of OHCI operation.  Is this normal / expected behavior when no USB devices are attached?

If there is anything I should provide to debug the user-visible problem (namely severe USB keyboard input lag and extremely slow USB boot) please let me know.

Thanks!

Timothy Pearson <tpearson>
Mon 14 Mar 2016 08:27:27 PM UTC, comment #1: 

What makes you think that there is a detected constant addition of USB devices? CHANGED bit is not set. Can you try removing OHCI module altogether and see if the problem disappears?

Vladimir Serbinenko <phcoder>
Group administrator
Mon 14 Mar 2016 05:51:05 AM UTC, original submission:  

When booted from coreboot on the KFSN4-DRE, KGPE-D16, or KCMA-D8 systems, GRUB2 operates extremely slowly, constantly detecting new USB devices even when no USB devices are actually present.  Verbose logging shows a continuous stream of the following messages:

bus/usb/ohci.c:1308: detect_dev status=0x100
bus/usb/ohci.c:1308: detect_dev status=0x303
bus/usb/ohci.c:1308: detect_dev status=0x100
bus/usb/ohci.c:1308: detect_dev status=0x100
bus/usb/ohci.c:1308: detect_dev status=0x100
bus/usb/ohci.c:1308: detect_dev status=0x100
bus/usb/ohci.c:1308: detect_dev status=0x100
bus/usb/ohci.c:1308: detect_dev status=0x100
bus/usb/ohci.c:1308: detect_dev status=0x100
bus/usb/ohci.c:1308: detect_dev status=0x100
bus/usb/ohci.c:1308: detect_dev status=0x100
bus/usb/ohci.c:1308: detect_dev status=0x100
bus/usb/ohci.c:1308: detect_dev status=0x100
bus/usb/ohci.c:1308: detect_dev status=0x100
bus/usb/ohci.c:1308: detect_dev status=0x100
bus/usb/ohci.c:1308: detect_dev status=0x303
bus/usb/ohci.c:1308: detect_dev status=0x100

This constant activity makes GRUB2 effectively unusable; USB keystrokes take seconds to process per keystroke and booting from USB is all but impossible.

The affected chipsets thus far are:
nVidia CK804
AMD SB700

Timothy Pearson <tpearson>

 

(Note: upload size limit is set to 16384 kB, after insertion of the required escape characters.)

No files currently attached

 

Depends on the following items: None found

Items that depend on this one: None found

 

Carbon-Copy List
  • -email is unavailable- added by phcoder (Posted a comment)
  • -email is unavailable- added by tpearson (Submitted the item)
  •  

    There are 0 votes so far. Votes easily highlight which items people would like to see resolved in priority, independently of the priority of the item set by tracker managers.

     

    Follow 2 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    2016-10-11 phcoder Priority5 - Normal 6
    2016-03-15 phcoder Planned ReleaseNone 2.02

    Back to the top

    Powered by Savane 3.13-f8d8.
    Corresponding source code