[Nut-upsuser] 18.104.22.168: Intel P55 Chipset BUG [usbhid-raw/devices/broken?] [tested 3 different UPS']
jpiszcz at lucidpixels.com
Sun Nov 1 21:25:33 UTC 2009
On Sun, 1 Nov 2009, Justin Piszcz wrote:
> On Sun, 1 Nov 2009, Matthew Dharm wrote:
>> On Sun, Nov 01, 2009 at 12:11:44PM -0500, Alan Stern wrote:
>>> On Sat, 31 Oct 2009, Justin Piszcz wrote:
>>>> 1. 5 minutes of usbmon output on via chipset [working]
>>>> 2. 5 minutes of usbmon output on intel p55 usb chipset [ehci/not working]
>>> To summarize the differences between the logs, the Intel controller
>>> shows occasional instances of failed transfers like this:
>>> ffff8802138c8500 3487005687 S Ci:2:004:0 s 81 06 2100 0000 0009 9 <
>>> ffff8802138c8500 3487006051 C Ci:2:004:0 -32 0
>>> while the corresponding transfers worked with the VIA controller:
>>> ffff88020c46dd40 1774844264 S Ci:4:002:0 s 81 06 2100 0000 0009 9 <
>>> ffff88020c46dd40 1774855248 C Ci:4:002:0 0 9 = 09211001 21012237 04
>>> and indeed they worked in the other Intel logs (the failures appeared
>>> to be more or less at random).
>>> This does indeed look like a low-level hardware problem, but I'm
>>> hesitant to blame it on the chipset. For example, the problem might
>>> lie in the hub you've got between the UPS and the computer. I know,
>>> this doesn't explain why everything works okay with the VIA controller.
>>> Probably the only way to tell for sure what's really happening is by
>>> using an expensive bus analyzer.
>>> Have you tried bypassing that hub, and plugging the UPS directly into
>>> the computer?
> I do not use any hubs in this environment, everything is directly attached to
> the motheboard. Per Matthew (noted below) when I
> mention hub I am talking about your typical USB hub one would
> attach to a USB port on the board, not the integrated one on the
> motherboard. Everything is directly attached from the motherboard
> to each respective device.
> MOBO -> UPS
> MOBO -> KBD
> MOBO -> etc
>> I think P55 chipset has an integrated hub, which is not removeable. The
>> only USB controller is EHCI, and that is connected directly to a hub in the
>> silicon which provides multiple downstream ports and does the translation
>> to 1.0 speeds. So the hub cannot be bypassed.
>> Two things to note:
>> 1) Not all ports on that silicon are the same. Specifically, ports 1 and 9
>> have special properties (related to USB-based debugging). You should try
>> other ports (note that I count ports starting at 0).
> I have tested every port on the motherboard (the 8 on the back and 4 off
> of the USB headers on the motherboard):
> The problem occurred on every port.
>> 2) I noticed this article:
>> http://www.theregister.co.uk/2009/10/30/iphone_p55_problems/ -- this may
>> suggest that there are other issues with P55 chipset and USB. According to
>> this article, as with this reported issue, adding an external USB hub
>> doesn't help, but an add-in PCI USB card does. We may have to consider a
>> P55 issue as a possibility here.
> Very interesting-- the C-state option for the CPU is on/enabled in the
> BIOS, it has always remained on, I never disabled it.
One note to add:
There is one final port on the motherboard itself near the CPU
but I would need to remove my motherboard and HSF/remove many cards etc
to be able to test that one.
All ports besides the one directly on the motherboard have been tested and
the error persists on them.
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