From mboxrd@z Thu Jan 1 00:00:00 1970 From: MAEDA Naoaki Date: Mon, 24 May 2004 02:54:38 +0000 Subject: Re: /proc/ioports regression in 2.6.6 on Tiger4 Message-Id: <20040524.115438.122622110.maeda@jp.fujitsu.com> List-Id: References: <20040513.182357.104026513.maeda@jp.fujitsu.com> In-Reply-To: <20040513.182357.104026513.maeda@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org Hi, David. Could you consider to apply this Matthew's patch that fixes the regression of /proc/ioports? Thanks, Naoaki Maeda diff -urp a/arch/ia64/pci/pci.c b/arch/ia64/pci/pci.c --- a/arch/ia64/pci/pci.c 2004-05-13 12:19:52.000000000 -0700 +++ b/arch/ia64/pci/pci.c 2004-05-13 12:21:32.000000000 -0700 @@ -323,8 +323,10 @@ pcibios_fixup_device_resources (struct p struct pci_controller *controller = PCI_CONTROLLER(dev); struct pci_window *window; int i, j; + int limit = (dev->hdr_type = PCI_HEADER_TYPE_NORMAL) ? \ + PCI_ROM_RESOURCE : PCI_NUM_RESOURCES; - for (i = 0; i < PCI_NUM_RESOURCES; i++) { + for (i = 0; i < limit; i++) { if (!dev->resource[i].start) continue; From: Chris McDermott Subject: Re: /proc/ioports regression in 2.6.6 on Tiger4 Date: Thu, 13 May 2004 12:28:37 -0700 > On Thu, May 13, 2004 at 18:23 +0900, MAEDA Naoaki wrote: > > Hi, > > > > Since 2.6.6, "cat /proc/ioports" loops infinity on Tiger4, because > > there is a loop in ioport_resource tree. > > > > $ cat /proc/ioports > > 00000000-00005fff : PCI Bus 0000:00 > > 00000060-0000006f : i8042 > > 000001f0-000001f7 : ide0 > > 000003c0-000003df : vga+ > > 000003f6-000003f6 : ide0 > > 00000500-0000053f : 0000:00:1f.0 > > 00000500-0000053f : 0000:00:1f.0 > > 00000500-0000053f : 0000:00:1f.0 > > 00000500-0000053f : 0000:00:1f.0 > > 00000500-0000053f : 0000:00:1f.0 > > 00000500-0000053f : 0000:00:1f.0 > > 00000500-0000053f : 0000:00:1f.0 > > 00000500-0000053f : 0000:00:1f.0 > > 00000500-0000053f : 0000:00:1f.0 > > 00000500-0000053f : 0000:00:1f.0 > > 00000500-0000053f : 0000:00:1f.0 > > 00000500-0000053f : 0000:00:1f.0 > > 00000500-0000053f : 0000:00:1f.0 > > ... > > > > $ /sbin/lspci -vs 00:1f.0 > > 00:1f.0 ISA bridge: Intel Corp. 82801DB LPC Interface Controller (rev 02) > > Flags: bus master, medium devsel, latency 0 > > > > 0000:00:1f.0, which causes the loop, is an Intel LPC interface bridge, > > and quirk_ich4_lpc_acpi() has become called for the bridge since 2.6.6. > > > > The reason of the loop is, pci_claim_resource() is issued twice with > > the exactly same resource structure, the first one is called by > > quirk_io_region() for quirk_ich4_lpc_acpi() at pci_fixup_device() and > > the second one is called by pcibios_fixup_device_resources(), > > and in this condition, insert_resource() sets the resource's child pointer > > to itself. Oviously, it causes the loop. > > Ran into the same problem on an IBM ia64 system (x455). Although, the x455 has > a different Southbridge, so the same device was being added to the resource > tree twice, from pcibios_fixup_device_resources() and from quirk_io_region() > (called from quirk_vt82c686_acpi()), in our case. > > > > > There are a few ways to fix the problem as following, but I'm not sure > > which one is the best. > > > > 1) Do not claim the resource in quirk_io_region(). > > 2) Put additional check in pcibios_fixup_device_resources() if the resource > > has already been claimed. > > 3) Modify insert_resource() not to claim the resource that has already been > > claimed and return with -EBUSY. > > > > Does anybody have comments? > > > > Yep, I considered these 3 options, plus a few others. None of the solutions > seemed very clean, though. In the end I decided to ask Matthew Wilcox about > this. He provided the following patch to correct the problem. Please try this > out and if it works for you, we'll ask David to apply. > > thanks, > -- > -chris > > Chris McDermott > IBM Linux Technology Center (LTC) > xSeries Platform Enablement > lcm@us.ibm.com > > > diff -urp a/arch/ia64/pci/pci.c b/arch/ia64/pci/pci.c > --- a/arch/ia64/pci/pci.c 2004-05-13 12:19:52.000000000 -0700 > +++ b/arch/ia64/pci/pci.c 2004-05-13 12:21:32.000000000 -0700 > @@ -323,8 +323,10 @@ pcibios_fixup_device_resources (struct p > struct pci_controller *controller = PCI_CONTROLLER(dev); > struct pci_window *window; > int i, j; > + int limit = (dev->hdr_type = PCI_HEADER_TYPE_NORMAL) ? \ > + PCI_ROM_RESOURCE : PCI_NUM_RESOURCES; > > - for (i = 0; i < PCI_NUM_RESOURCES; i++) { > + for (i = 0; i < limit; i++) { > if (!dev->resource[i].start) > continue; > > - > To unsubscribe from this list: send the line "unsubscribe linux-ia64" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html