On 03/18/2016 07:28 AM, Lorenzo Pieralisi wrote:
> On Thu, Mar 17, 2016 at 05:28:31PM -0400, Murali Karicheri wrote:
>
> [...]
>
>>> 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?
>>
>> Yes we are in the path.
>>
>>
>> [ 1.557561] ahci_init_one
>> [ 1.560214] ahci 0000:01:00.0: version 3.0
>> [ 1.564302] pcim_enable_device
>> [ 1.567349] pci_enable_device
>> [ 1.570340] pci_enable_device_flags
>> [ 1.573824] do_pci_enable_device
>> [ 1.577042] pcibios_enable_device
>> [ 1.580380] pci_enable_resources
>
> So resources are actually enabled (ie PCI_PROBE_ONLY is not set)
> and that makes sense otherwise you would not be able to use the
> MEM resources anyway (ie they would not be enabled).
>
> I suspect the PCI dev IO resources were reset in reset_resource() in
> assign_requested_resource_sorted(), hence the bar mask that is built
> in pci_enable_device_flags() does not contain the IO resources,
> it would be helpful if you can print the bar mask passed to
> pcibios_enable_device() (ie the mask parameter).
Here it is
[ 1.556507] ahci_init_one
[ 1.559124] ahci 0000:01:00.0: version 3.0
[ 1.563246] pcim_enable_device
[ 1.566294] pci_enable_device
[ 1.569252] pci_enable_device_flags
[ 1.572766] do_pci_enable_device
[ 1.575985] pcibios_enable_device 60
[ 1.579551] pci_enable_resources
I know that some of our customers use PCIe SATA from u-boot and would
like to honor the assignment in Linux space.. I believe they use PCI_PROBE_ONLY
by setting the bootarg. So Keystone PCI should work in both cases.
Murali
>
> Not saying that's what should happen, I think that's what's happening,
> that's the only reason I see why you do not have pci_enable_resources()
> failures when you remove the IO range from the host bridge.
>
> Lorenzo
>
>> [ 1.583608] ahci 0000:01:00.0: limiting MRRS to 256
>> [ 1.588595] ahci 0000:01:00.0: AHCI 0001.0000 32 slots 2 ports 6 Gbps 0x3 impl SATA mode
>> [ 1.596716] ahci 0000:01:00.0: flags: 64bit ncq sntf led only pmp fbs pio slum part sxs
>> [ 1.606183] scsi host0: ahci
>> [ 1.609448] scsi host1: ahci
>> [ 1.612636] ata1: SATA max UDMA/133 abar m512@0x60000000 port 0x60000100 irq 82
>> [ 1.619974] ata2: SATA max UDMA/133 abar m512@0x60000000 port 0x60000180 irq 82
>>
>>>
>>>> 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
>> --
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>>
--
Murali Karicheri
Linux Kernel, Keystone
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