On 03/16/2016 05:47 PM, Bjorn Helgaas wrote: > On Wed, Mar 16, 2016 at 04:13:30PM -0400, Murali Karicheri wrote: >> On 03/16/2016 03:29 PM, Bjorn Helgaas wrote: >>> On Wed, Mar 16, 2016 at 02:08:47PM -0400, Murali Karicheri wrote: >>>> Bjorn, >>>> >>>> Thanks for your quick response! Please see below some clarification >>>> and follow up question. >>>> >>>> On 03/16/2016 12:45 PM, Bjorn Helgaas wrote: >>>> 0x1000] >>>>> >>>>> Obviously if the host bridge doesn't support I/O port space, we will >>>>> be unable to assign space for I/O BARs, so you will see errors like >>>>> this. >>>>> >>>>> We may be able to improve the message and/or make this less noisy. >>>>> Guenter Roeck looked at a similar issue a while ago, but it's not >>>>> completely trivial: >>>>> >>>>> http://lkml.kernel.org/r/20150515172836.GA27797@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx >>>>> >>>>> The PCI core should check in pci_enable_device() whether all the >>>>> device BARs have been assigned. If not, it should fail. But if a >>>>> driver doesn't need I/O space, it can use pci_enable_device_mem() to >>>>> indicate that it only needs the MEM BARs. That should succeed even if >>>>> the I/O BARs aren't assigned. >>>>> >>>>> Bottom line, if you omit I/O space on your host bridge: >>>>> >>>>> - You will see annoying "no space for" and "failed to assign" messages >>>>> - Drivers that don't need I/O ports should still work >>>>> - It's far better to have the messages than it was to pretend that >>>>> the host bridge supported I/O space when it really didn't. >>>>> >>>>>> [ 0.448813] pci 0000:01:00.0: BAR 6: assigned [mem 0x60100000-0x6010ffff pref] >>>>>> [ 0.448822] pci 0000:01:00.0: BAR 5: assigned [mem 0x60000000-0x600001ff] >>>>>> [ 0.448834] pci 0000:01:00.0: BAR 4: no space for [io size 0x0010] >>>>>> [ 0.448841] pci 0000:01:00.0: BAR 4: failed to assign [io size 0x0010] >>>>>> [ 0.448848] pci 0000:01:00.0: BAR 0: no space for [io size 0x0008] >>>>>> [ 0.448855] pci 0000:01:00.0: BAR 0: failed to assign [io size 0x0008] >>>>>> [ 0.448863] pci 0000:01:00.0: BAR 2: no space for [io size 0x0008] >>>>>> [ 0.448870] pci 0000:01:00.0: BAR 2: failed to assign [io size 0x0008] >>>>>> [ 0.448877] pci 0000:01:00.0: BAR 1: no space for [io size 0x0004] >>>>>> [ 0.448884] pci 0000:01:00.0: BAR 1: failed to assign [io size 0x0004] >>>>>> [ 0.448891] pci 0000:01:00.0: BAR 3: no space for [io size 0x0004] >>>>>> [ 0.448898] pci 0000:01:00.0: BAR 3: failed to assign [io size 0x0004] >>>>>> [ 0.448907] pci 0000:00:00.0: PCI bridge to [bus 01] >>>>>> >>>>>> >>>>>> The original log is below and even with the error, I am able to have SATA >>>>>> drive function as expected over this PCIe interface. >>>>>> >>>>>> >>>>>> [ 0.420648] PCI host bridge /soc/pcie@21020000 ranges: >>>>>> [ 0.420659] No bus range found for /soc/pcie@21020000, using [bus 00-ff] >>>>>> [ 0.420679] IO 0x23260000..0x400023263fff -> 0x00000000 >>>>>> [ 0.420685] Requested IO range too big, new size set to 64K >>>>>> [ 0.420702] MEM 0x60000000..0x6fffffff -> 0x60000000 >>>>>> [ 0.420713] keystone-pcie 21021000.pcie: error -22: failed to map resource [io 0x0000-0x400000003fff] >>>>>> [ 0.431849] keystone-pcie 21021000.pcie: PCI host bridge to bus 0000:00 >>>>>> [ 0.431861] pci_bus 0000:00: root bus resource [bus 00-ff] >>>>>> [ 0.431870] pci_bus 0000:00: root bus resource [io 0x0000-0x400000003fff] >>>>> >>>>> This range is obviously bogus, since it's way too big and not a nice >>>>> round size. I guess this is what you're fixing. >>>> >>>> Yes. But from your response, I gather it is better to remove the bogus range. >>>> I removed the range, and did a read/write test to the hard drive connected >>>> to the Marvel SATA that is hooked to the PCIe interface and it still work >>>> without issues. >>> >>> If your bridge doesn't support I/O space, you should definitely remove >>> the range. >>> >> Ok. Will do. >> >>> I'm curious about this Marvell SATA device, though. It is this >>> device? >>> >> >> Yes. >> >>> pci 0000:01:00.0: [1b4b:9182] type 00 class 0x010601 >>> pci 0000:01:00.0: reg 0x10: [io 0x8000-0x8007] >>> pci 0000:01:00.0: reg 0x14: [io 0x8040-0x8043] >>> pci 0000:01:00.0: reg 0x18: [io 0x8100-0x8107] >>> pci 0000:01:00.0: reg 0x1c: [io 0x8140-0x8143] >>> pci 0000:01:00.0: reg 0x20: [io 0x800000-0x80000f] >>> pci 0000:01:00.0: reg 0x24: [mem 0x00900000-0x009001ff] >>> pci 0000:01:00.0: reg 0x30: [mem 0xd0000000-0xd000ffff pref] >>> >>> If so, it looks like it uses the drivers/ata/ahci.c driver, which uses >>> pcim_enable_device(), which should require all BARs to be assigned. >>> (It doesn't look like there is a pcim_enable_device_mem() variant.) >>> >> What does it mean in the context of removing the IO resource DT binding? >> My AHCI SATA driver works fine with the IO DT bindings removed except >> that I see the the error log for assigning IO BAR >> >> If it expects all resources to be assigned, then it should have >> failed, right? But not. > > Right, I'm expecting the SATA driver to fail when you remove the DT I/O > resource binding. I want to figure out why it doesn't fail. > >> I see following >> >> [ 1.547690] ahci 0000:01:00.0: version 3.0 >> [ 1.551833] ahci 0000:01:00.0: limiting MRRS to 256 >> [ 1.556822] ahci 0000:01:00.0: AHCI 0001.0000 32 slots 2 ports 6 Gbps 0x3 impl SATA mode >> [ 1.564943] ahci 0000:01:00.0: flags: 64bit ncq sntf led only pmp fbs pio slum part sxs >> >> >> And Then >> >> [ 1.940284] ata1: SATA link down (SStatus 0 SControl 300) >> [ 2.140278] ata2: SATA link up 6.0 Gbps (SStatus 133 SControl 300) >> [ 2.147029] ata2.00: ATA-9: WDC WD10EZEX-08M2NA0, 01.01A01, max UDMA/100 >> [ 2.153752] ata2.00: 1953525168 sectors, multi 0: LBA48 NCQ (depth 31/32), AA >> [ 2.161524] ata2.00: configured for UDMA/100 >> [ 2.165957] bounce: isa pool size: 16 pages >> [ 2.170289] scsi 1:0:0:0: Direct-Access ATA WDC WD10EZEX-08M 1A01 PQ: 0 ANSI: 5 >> [ 2.178967] sd 1:0:0:0: [sda] 1953525168 512-byte logical blocks: (1.00 TB/932 GiB) >> [ 2.186632] sd 1:0:0:0: [sda] 4096-byte physical blocks >> [ 2.192047] sd 1:0:0:0: [sda] Write Protect is off >> [ 2.196835] sd 1:0:0:0: [sda] Mode Sense: 00 3a 00 00 >> [ 2.201968] sd 1:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA >> [ 2.226610] sda: sda1 sda2 >> [ 2.230300] sd 1:0:0:0: [sda] Attached SCSI removable disk >> >> >>> But if you're on an arm or arm64 platform and you have PCI_PROBE_ONLY >>> set, pcibios_enable_device() doesn't check whether resources are >>> assigned, so the problem would be masked. We're trying to remove >>> PCI_PROBE_ONLY, or at least remove it from paths like this, so this >>> might become a problem soon. >>> >> >> Keystone is ARM v7 A15 based. The driver doesn't set PCI_PROBE_ONLY. >> So am expect face problem when you remove PCI_PROBE_ONLY? I guess not. > > The only ways I see that PCI_PROBE_ONLY can be set on ARM are if you have > "linux,pci-probe-only" in your DT or you boot with "pci=firmware". > > I expect you're in this path: > > ahci_init_one > pcim_enable_device > pci_enable_device > pci_enable_device_flags(dev, IORESOURCE_MEM | IORESOURCE_IO) > # build "bars" mask > do_pci_enable_device(dev, bars) > pcibios_enable_device > if (pci_has_flag(PCI_PROBE_ONLY)) > return 0; > pci_enable_resources > > Can you add a little debug code like this to verify that we're in this > path? > Will do, but need sometime. Will post once done. Murali >> I looked at pci_enable_resources() >> >> for (i = 0; i < PCI_NUM_RESOURCES; i++) { >> if (!(mask & (1 << i))) >> continue; >> >> r = &dev->resource[i]; > > dev_info(&dev->dev, "BAR %d %pR mask %#04x parent %p\n", i, r, mask, r->parent); > >> >> if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM))) >> continue; >> if ((i == PCI_ROM_RESOURCE) && >> (!(r->flags & IORESOURCE_ROM_ENABLE))) >> continue; >> >> if (r->flags & IORESOURCE_UNSET) { >> dev_err(&dev->dev, "can't enable device: BAR %d %pR not assigned\n", >> i, r); >> return -EINVAL; >> } >> >> if (!r->parent) { >> dev_err(&dev->dev, "can't enable device: BAR %d %pR not claimed\n", >> i, r); >> return -EINVAL; >> } >> >> I don't see the error "can't enable device: BAR %d %pR not assigned" , so it doesn't >> depend on IO bar as you mention below or is it in a different function? > -- Murali Karicheri Linux Kernel, Keystone -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
