Re: Null Pointer BUG in uhci_hcd

Alan Stern
2009-07-09T14:20:38Z

On Wed, 8 Jul 2009, Michael S. Zick wrote:

> > > > > For more information enable CONFIG_USB_DEBUG and CONFIG_DEBUG_FS, then
> > > > > see what's sitting in the usb/uhci/* files in debugfs.
> > > > >
> > >
> > > Anything in particular to look for/at?
> >
> > Just post the contents of those files.
> >
> Done:
>
> root@cb01:/sys/kernel/debug/uhci# cat *
> Root-hub state: suspended FSBR: 0
> HC status
> usbcmd = 0048 Maxp32 CF EGSM
> usbstat = 0020 HCHalted
> usbint = 0002
> usbfrnum = (1)4a8
> flbaseadd = 19c7f000
> sof = 40
> stat1 = 0480 OverCurrent
> stat2 = 0480 OverCurrent
> Most recent frame: 52a (298) Last ISO frame: 52a (298)
> Periodic load table
> 0 0 0 0 0 0 0 0
> 0 0 0 0 0 0 0 0
> 0 0 0 0 0 0 0 0
> 0 0 0 0 0 0 0 0
> Total: 0, #INT: 0, #ISO: 0
> Root-hub state: suspended FSBR: 0
> HC status
> usbcmd = 0048 Maxp32 CF EGSM
> usbstat = 0020 HCHalted
> usbint = 0002
> usbfrnum = (1)4a0
> flbaseadd = 19c63000
> sof = 40
> stat1 = 0480 OverCurrent
> stat2 = 0480 OverCurrent
> Most recent frame: 528 (296) Last ISO frame: 528 (296)
> Periodic load table
> 0 0 0 0 0 0 0 0
> 0 0 0 0 0 0 0 0
> 0 0 0 0 0 0 0 0
> 0 0 0 0 0 0 0 0
> Total: 0, #INT: 0, #ISO: 0
> Root-hub state: running FSBR: 0
> HC status
> usbcmd = 00c1 Maxp64 CF RS
> usbstat = 0000
> usbint = 000f
> usbfrnum = (0)c1c
> flbaseadd = 19c9c000
> sof = 40
> stat1 = 0495 OverCurrent Enabled Connected
> stat2 = 0495 OverCurrent Enabled Connected
> Most recent frame: 56aee (750) Last ISO frame: 56aee (750)
> Periodic load table
> 0 0 0 0 0 0 0 0
> 0 0 0 0 0 0 0 0
> 17 0 0 0 0 0 0 0
> 0 0 0 0 0 0 0 0
> Total: 17, #INT: 1, #ISO: 0
>
> And, at no extra cost:
>
> root@cb01:/sys/kernel/debug/ehci/0000:00:10.4# cat *
> size = 256
> bus pci, device 0000:00:10.4
> EHCI Host Controller
> EHCI 1.00, hcd state 4
> ownership 01000001 linux
> SMI sts/enable 0xe00f0000
> structural params 0x00103206
> capability params 0x00006872
> status 100f Halt FLR PCD ERR INT
> command 010008 (park)=0 ithresh=1 period=256 HALT
> intrenable 37 IAA FATAL PCD ERR INT
> uframe 14db
> port 1 status 701000 POWER sig=se0
> port 2 status 701000 POWER sig=se0
> port 3 status 701000 POWER sig=se0
> port 4 status 701000 POWER sig=se0
> port 5 status 703802 POWER OWNER sig=j CSC
> port 6 status 703802 POWER OWNER sig=j CSC
> irq normal 0 err 0 reclaim 0 (lost 20)
> complete 0 unlink 20

Those files all look perfectly normal. You made these copies at a time
when everything was working, right? It will be more interesting to see
them at a time when something isn't working.

Alan Stern