On Wed, Mar 16, 2016 at 12:20:08PM -0400, Murali Karicheri wrote: > Bjorn, > > Keystone PCI h/w doesn't support IO access in the inbound direction > as stated in the hardware spec cut-n-pasted below. > > • No support for IO access in inbound direction in RC or EP mode > > Way back when the driver was ported, I vaguely recollect I had to > add a dummy IO range to satisfy PCI Driver core. I am assuming the > first entry in the DTS is for this IO port access. Is it true? The PCI core should not require an I/O range. > arch/arm/boot/dts/k2e.dtsi > > ranges = <0x81000000 0 0 0x23260000 0x4000 0x4000 > 0x82000000 0 0x60000000 0x60000000 0 0x10000000>; > > I see following boot log when I boot with 4.4.x kernel > > >> keystone-pcie 21021000.pcie: error -22: failed to map resource [io 0x0000-0x400000003fff] > > I need to fix the above entry to > > - ranges = <0x81000000 0 0 0x23260000 0x4000 0x4000 > + ranges = <0x81000000 0 0 0x23260000 0x0 0x4000 > 0x82000000 0 0x60000000 0x60000000 0 0x10000000>; > > > to remove this error message. > > However I am wondering if it is mandatory to define this range at all. I tried > to remove the entry and I get following error then > > [ 0.448772] pci 0000:00:00.0: BAR 8: assigned [mem 0x60000000-0x600fffff] > [ 0.448783] pci 0000:00:00.0: BAR 9: assigned [mem 0x60100000-0x601fffff pref] > [ 0.448792] pci 0000:00:00.0: BAR 7: no space for [io size 0x1000] > [ 0.448800] pci 0000:00:00.0: BAR 7: failed to assign [io size 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. > [ 0.431879] pci_bus 0000:00: root bus resource [mem 0x60000000-0x6fffffff] > [ 0.431906] pci 0000:00:00.0: [104c:b009] type 01 class 0x060400 > [ 0.432173] PCI: bus0: Fast back to back transfers disabled > [ 0.432334] pci 0000:01:00.0: [1b4b:9182] type 00 class 0x010601 > [ 0.432382] pci 0000:01:00.0: reg 0x10: [io 0x8000-0x8007] > [ 0.432402] pci 0000:01:00.0: reg 0x14: [io 0x8040-0x8043] > [ 0.432420] pci 0000:01:00.0: reg 0x18: [io 0x8100-0x8107] > [ 0.432439] pci 0000:01:00.0: reg 0x1c: [io 0x8140-0x8143] > [ 0.432457] pci 0000:01:00.0: reg 0x20: [io 0x800000-0x80000f] > [ 0.432476] pci 0000:01:00.0: reg 0x24: [mem 0x00900000-0x009001ff] > [ 0.432495] pci 0000:01:00.0: reg 0x30: [mem 0xd0000000-0xd000ffff pref] > [ 0.432561] pci 0000:01:00.0: PME# supported from D3hot > [ 0.448635] PCI: bus1: Fast back to back transfers disabled > [ 0.448717] pci 0000:00:00.0: BAR 8: assigned [mem 0x60000000-0x600fffff] > [ 0.448729] pci 0000:00:00.0: BAR 9: assigned [mem 0x60100000-0x601fffff pref] > [ 0.448738] pci 0000:00:00.0: BAR 7: assigned [io 0x1000-0x1fff] > [ 0.448751] pci 0000:01:00.0: BAR 6: assigned [mem 0x60100000-0x6010ffff pref] > [ 0.448760] pci 0000:01:00.0: BAR 5: assigned [mem 0x60000000-0x600001ff] > [ 0.448772] pci 0000:01:00.0: BAR 4: assigned [io 0x1000-0x100f] > [ 0.448784] pci 0000:01:00.0: BAR 0: assigned [io 0x1010-0x1017] > [ 0.448796] pci 0000:01:00.0: BAR 2: assigned [io 0x1018-0x101f] > [ 0.448808] pci 0000:01:00.0: BAR 1: assigned [io 0x1020-0x1023] > [ 0.448820] pci 0000:01:00.0: BAR 3: assigned [io 0x1024-0x1027] > [ 0.448833] pci 0000:00:00.0: PCI bridge to [bus 01] > [ 0.448842] pci 0000:00:00.0: bridge window [io 0x1000-0x1fff] > [ 0.448851] pci 0000:00:00.0: bridge window [mem 0x60000000-0x600fffff] > [ 0.448860] pci 0000:00:00.0: bridge window [mem 0x60100000-0x601fffff pref] > [ 0.449077] pcieport 0000:00:00.0: Signaling PME through PCIe PME interrupt > [ 0.449086] pci 0000:01:00.0: Signaling PME through PCIe PME interrupt > [ 0.449095] pcie_pme 0000:00:00.0:pcie01: service driver pcie_pme loaded > [ 0.449240] aer 0000:00:00.0:pcie02: service driver aer loaded > > > Thanks and regards, > > -- > 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 -- 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
