Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755845AbXKWEcQ (ORCPT ); Thu, 22 Nov 2007 23:32:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753987AbXKWEcB (ORCPT ); Thu, 22 Nov 2007 23:32:01 -0500 Received: from nmta.jpl.nasa.gov ([137.78.160.215]:29448 "EHLO nmta2.jpl.nasa.gov" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753538AbXKWEcA convert rfc822-to-8bit (ORCPT ); Thu, 22 Nov 2007 23:32:00 -0500 Message-ID: <20071122203135.qjoylea4gwc8cs08@webmail.jpl.nasa.gov> Date: Thu, 22 Nov 2007 20:31:35 -0800 From: niessner@jpl.nasa.gov To: Marin Mitov Cc: linux-kernel@vger.kernel.org Subject: Re: Where is the interrupt going? References: <1195693710.5544.240.camel@morte.jpl.nasa.gov> <20071122022004.GB9265@fattire.cabal.ca> <20071122164853.cfdplzj5o744sw40@webmail.jpl.nasa.gov> <200711230518.01401.mitov@issp.bas.bg> In-Reply-To: <200711230518.01401.mitov@issp.bas.bg> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; DelSp="Yes"; format="flowed" Content-Disposition: inline Content-Transfer-Encoding: 8BIT User-Agent: Internet Messaging Program (IMP) H3 (4.1.3) X-Source-IP: webmail1.jpl.nasa.gov [137.78.160.101] X-Source-Sender: niessner@jpl.nasa.gov X-AUTH: Authorized Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7735 Lines: 179 Quite right. I read it too quickly and thought it had succeeded when it had failed. I will modify the module to do the shared IRQ and then try the noapic test again. Exactly why I reserved the right to do it again. This is good because it means the hammer may work after all. Thank you very much and I will post to let you know the outcome. Quoting Marin Mitov , on Thu 22 Nov 2007 07:18:01 PM PST: > Hi, > > On Friday 23 November 2007 02:48:53 am you wrote: >> I tried the hammer and the problem persists. >> observer@bbb:~$ cat /proc/cmdline >> root=UUID=8b3c3666-22c3-4c04-b399-ece266f2ef30 ro noapic quiet splash >> >> However, I reserve the right to try the hammer again in the future. >> When I look at /proc/interrupts without the APIC: >> observer@bbb:~$ cat /proc/interrupts >> CPU0 >> 0: 144 XT-PIC-XT timer >> 1: 10 XT-PIC-XT i8042 >> 2: 0 XT-PIC-XT cascade >> 5: 100000 XT-PIC-XT ohci_hcd:usb5, mxser >> 6: 5 XT-PIC-XT floppy >> 7: 1 XT-PIC-XT parport0 >> 8: 3 XT-PIC-XT rtc >> 9: 1 XT-PIC-XT acpi, uhci_hcd:usb2 >> 10: 100000 XT-PIC-XT ohci_hcd:usb4, ehci_hcd:usb6, >> r128@pci:0000:01:00.0 >> 11: 2231 XT-PIC-XT uhci_hcd:usb1, ohci_hcd:usb3, eth0 >> 12: 130 XT-PIC-XT i8042 >> 14: 4362 XT-PIC-XT libata >> 15: 15315 XT-PIC-XT libata >> NMI: 0 >> LOC: 130125 >> ERR: 0 >> MIS: 0 >> >> I do not even see the device that I registered unless it is that >> r128... line. However the code printed out in /var/log/messages: > > No, this is your radeon 128 board (on AGP I suppose). Could be integrated > on the mobo if it is a server mobo. > >> Nov 22 16:05:27 bbb kernel: [ 104.712473] apc8620: VID = 0x10B5 >> Nov 22 16:05:27 bbb kernel: [ 104.712486] apc8620: mapped addr = e0bd4000 >> Nov 22 16:05:27 bbb kernel: [ 104.713022] apc8620: registered carrier 0 >> Nov 22 16:05:27 bbb kernel: [ 104.713028] apc8620: interrupt data >> (0xe1083e40) on irq (10) and status (0x10) > > Here is the problem (I suppose): > if status (0x10 hex or 16 decimal) is the value returned by request_irq: > status = request_irq (apcsi[i].board_irq, > apc8620_handler, > IRQF_DISABLED, > DEVICE_NAME, > (void*)&apcsi[i]); > (from your first post), that means the irq is NOT registered, because > according to the LDD v.3 book: > > The value returned from request_irq to the requesting function is either 0 > to indicate success or a negative error code, as usual. It’s not uncommon > for the function to return -EBUSY to signal that another driver is already > using the requested interrupt line. > > If you grep the kernels's include directory for EBUSY you will find: > #define EBUSY 16 /* Device or resource busy */ > in include/asm-generic/errno-base.h > > So I think your mobo has shared (with other devices) irq line on the > PCI/PCIe slot you use for your hardware and these other devices have > already registered shered irq handlers for the same irq (10), so the > attempt to register nonshared irq fails. > > Either try to register the irq as shared, or put the hardware on > another slot whose irq line is not shared with other devises > (if such one exists). This info should be available from the mobo > manual book. >> >> which indicates it successfully registered without being shared. > > No, as I already explained. > The only problem :-) in my explanation is: > request_irq returns EBUSY (not -EBUSY as should be) > > Marin Mitov > >> When >> I have more time, I will changed the code to be a shared IRQ and try >> the noapic again. >> >> However, without the noapic /proc/interrupts looks like: >> observer@bbb:~$ cat /proc/interrupts >> CPU0 >> 0: 154 IO-APIC-edge timer >> 1: 10 IO-APIC-edge i8042 >> 6: 5 IO-APIC-edge floppy >> 7: 0 IO-APIC-edge parport0 >> 8: 3 IO-APIC-edge rtc >> 9: 1 IO-APIC-fasteoi acpi >> 10: 0 IO-APIC-edge apc8620 >> 12: 130 IO-APIC-edge i8042 >> 14: 2861 IO-APIC-edge libata >> 15: 1049 IO-APIC-edge libata >> 16: 100001 IO-APIC-fasteoi ohci_hcd:usb5, mxser >> 17: 0 IO-APIC-fasteoi uhci_hcd:usb1, ohci_hcd:usb3 >> 18: 0 IO-APIC-fasteoi uhci_hcd:usb2 >> 19: 187 IO-APIC-fasteoi eth0 >> 20: 0 IO-APIC-fasteoi ohci_hcd:usb4, r128@pci:0000:01:00.0 >> 21: 0 IO-APIC-fasteoi ehci_hcd:usb6 >> NMI: 0 >> LOC: 8820 >> ERR: 0 >> MIS: 0 >> >> >> I have attached the kernel module. The apc8620 is an IndustryPack >> carrier card. I can therefore open up N (in this specific case 5) sub >> memory windows in the memory mapped PCI address. The kernel module >> keeps track of the slot offsets from the memory mapped address so that >> the user can simply use read and write instead of a zillion ugly ioctl >> calls. Because the kernel module tracks the slot offsets, I place acp >> state into the private data of the file pointer. There can also be >> multiple carriers on the bus. So, the array in the kernel module keeps >> track of the card specific details with the file pointer the slot >> specific information. Both are the same structure (bad on my part I >> know but I never intended to show my dirty underwear). To get data >> from interrupts (asynchronous IO) I was using readv. Now I am using >> aio_read and had to make some minor changes that you will see comments >> about to accomidate the change. >> >> Just noticed that r128 is not the carrier card... >> >> Thanks for all of the help so far and I hope this information is helpful. >> >> I almost forgot. I also attached the dmesg output and will try the >> irqpoll as it suggests. It is just the IRQ 16 is not the one I am >> looking for, but is probably related to my mxser problems that I will >> get to later. >> >> Quoting Kyle McMartin , on Wed 21 Nov 2007 06:20:04 PM > PST: >> > On Wed, Nov 21, 2007 at 05:08:30PM -0800, Al Niessner wrote: >> >> On with the detailed technical information. I developed a kernel module >> >> for an PCI card back in 2.4, moved it to 2.6.3, then 2.6.11 or so and >> >> now I am trying to move it to 2.6.22. When I began the to move to >> >> 2.6.22, I changed all of the deprecated calls for finding the card on >> >> the PCI bus, modified the interrupt handler prototype, and changed my >> >> readvv/writev to aio_read/aio_write following >> >> http://lwn.net/Articles/202449/. So initialization looks like this: >> > >> > Hi Al, >> > >> > From the sounds of it, you might have an interrupt routing problem. Can >> > you describe the machine you have this plugged into? Possibly attaching >> > a copy of "dmesg" and "/proc/interrupts"? >> > >> > Feel free to attach the driver source to your email if the size is >> > reasonable (which it sounds like it is.) >> > >> > As a "big hammer" in case it is an APIC problem, please try booting the >> > kernel with the "noapic" parameter. >> > >> > cheers, >> > Kyle > > > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/