Re: XT-PIC interrupts blocked by usbserial ? [Was Re: Intel ICH9M bug : sata unusable with usbserial]

[Philippe De Muyter <phdm-vQo90/bmh3WzQB+pC5nmwQ@public.gmane.org>]

Hello Serguei,

On Thu, Mar 03, 2011 at 06:23:12PM +0300, Sergei Shtylyov wrote:
> Hello.
>
> Philippe De Muyter wrote:
>
>> Summary :
>
>> When I started to listen to a USB serial GPS receiver, the interrupts
>> of my sata disk were blocked until reboot :(
>
>> Switching in the BIOS from 'APIC disabled' to 'APIC enabled' made the 
>> problem
>> disappear.
>
>>>>>> previously we had all but one usb interrupts on the same line as 
>>>>>> ata_piix :
>>>>>>   5:      17183    XT-PIC-XT-PIC    ata_piix, ata_piix, ehci_hcd:usb1, 
>>>>>> ehci_hcd:usb2, uhci_hcd:usb3, uhci_hcd:usb5, uhci_hcd:usb6, 
>>>>>> uhci_hcd:usb7, uhci_hcd:usb8
>>>>>> while now they are spread on different lines : 16, 18, 19, 21 and 22
>
>>>>>> So I wonder if there is still a bug, but that it is not triggered 
>>>>>> anymore.
>
>>>>>> Is there a way to tell which interrupt line the USB GPS receiver is 
>>>>>> connected
>>>>>> to ?
>>>>> See which USB bus the device is on, using lsusb.  It should match up
>>>>> with the usbX number in the above list.
>
>>>> Given that I get :
>
>>>>   tmp199:~ # lsusb
>>>>   ...
>>>>   Bus 007 Device 002: ID 067b:2303 Prolific Technology, Inc. PL2303 
>>>> Serial Port
>>>>   tmp199:~ # cat /proc/interrupts
>>>> 	     CPU0       CPU1
>>>>   ...
>>>>    19:     996143     995511   IO-APIC-fasteoi   ata_piix, ata_piix, 
>>>> uhci_hcd:usb5, uhci_hcd:usb7
>>>>   tmp199:~ #
>
>>>> my USB GPS receiver and my sata disk still share the same interrupt, I 
>>>> assume ?
>
>>>> What's changed now is that this interrupt line is now IO-APIC-fasteoi 
>>>> instead
>>>> of XT-PIC-XT-PIC.  Maybe there's something to look at there ?
>
>>>>> Glad enabling APIC in your BIOS fixed this.
>
>>>> I am glad too :)
>
>>> Nothing got "fixed" by doing that.
>>> Swept under the rug, yes.
>
>>> But the bug is still there.
>
>> If it is a bug (what I also believe) it is not a new one :
>
>> Before installing 2.6.37-20-desktop (opensuse 11.4) on this new hardware,
>> I had the same problem with 2.6.31.14-0.6-desktop (opensuse 11.2) and
>> with 2.6.22.18-0.2-default (opensuse 10.3)
>
>> The only interesting file where I find the word 'XT-PIC' is
>> 	arch/alpha/kernel/irq_i8259.c
>
>    Why it's interesting if you're not really on Alpha? Because there is 
> also arch/x86/kernel/i8259.c (and several others)...

Sorry, I picked the wrong line when doing cut'n paste.  Of course, it is

	arch/x86/kernel/i8259.c

Best regards

Philippe

-- 
Philippe De Muyter +32 2 6101532 Macq SA rue de l'Aeronef 2 B-1140 Bruxelles
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