On Tue, 1 Apr 2025, Guenter Roeck wrote: > On 4/1/25 05:07, Ilpo Järvinen wrote: > > On Tue, 1 Apr 2025, Ilpo Järvinen wrote: > > > > > On Mon, 31 Mar 2025, Guenter Roeck wrote: > > > > On Mon, Dec 16, 2024 at 07:56:31PM +0200, Ilpo Järvinen wrote: > > > > > Resetting resource is problematic as it prevent attempting to allocate > > > > > the resource later, unless something in between restores the resource. > > > > > Similarly, if fail_head does not contain all resources that were > > > > > reset, > > > > > those resource cannot be restored later. > > > > > > > > > > The entire reset/restore cycle adds complexity and leaving resources > > > > > into reseted state causes issues to other code such as for checks done > > > > > in pci_enable_resources(). Take a small step towards not resetting > > > > > resources by delaying reset until the end of resource assignment and > > > > > build failure list (fail_head) in sync with the reset to avoid leaving > > > > > behind resources that cannot be restored (for the case where the > > > > > caller > > > > > provides fail_head in the first place to allow restore somewhere in > > > > > the > > > > > callchain, as is not all callers pass non-NULL fail_head). > > > > > > > > > > The Expansion ROM check is temporarily left in place while building > > > > > the > > > > > failure list until the upcoming change which reworks optional resource > > > > > handling. > > > > > > > > > > Ideally, whole resource reset could be removed but doing that in a big > > > > > step would make the impact non-tractable due to complexity of all > > > > > related code. > > > > > > > > > > Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> > > > > > > > > With this patch in the mainline kernel, all mips:boston qemu emulations > > > > fail when running a 64-bit little endian configuration > > > > (64r6el_defconfig). > > > > > > > > The problem is that the PCI based IDE/ATA controller is not initialized. > > > > There are a number of pci error messages. > > > > > > > > pci_bus 0002:01: extended config space not accessible > > > > pci 0002:01:00.0: [8086:2922] type 00 class 0x010601 conventional PCI > > > > endpoint > > > > pci 0002:01:00.0: BAR 4 [io 0x0000-0x001f] > > > > pci 0002:01:00.0: BAR 5 [mem 0x00000000-0x00000fff] > > > > pci 0002:00:00.0: PCI bridge to [bus 01-ff] > > > > pci_bus 0002:01: busn_res: [bus 01-ff] end is updated to 01 > > > > pci 0002:00:00.0: bridge window [mem 0x16000000-0x160fffff]: assigned > > > > pci 0002:00:00.0: bridge window [mem size 0x00100000 64bit pref]: can't > > > > assign; no space > > > > pci 0002:00:00.0: bridge window [mem size 0x00100000 64bit pref]: failed > > > > to assign > > > > pci 0002:00:00.0: bridge window [io size 0x1000]: can't assign; no > > > > space > > > > pci 0002:00:00.0: bridge window [io size 0x1000]: failed to assign > > > > pci 0002:00:00.0: bridge window [mem size 0x00100000]: can't assign; > > > > bogus alignment > > > > pci 0002:00:00.0: bridge window [mem 0x16000000-0x160fffff 64bit pref]: > > > > assigned > > > > pci 0002:00:00.0: bridge window [io size 0x1000]: can't assign; no > > > > space > > > > pci 0002:00:00.0: bridge window [io size 0x1000]: failed to assign > > > > pci 0002:01:00.0: BAR 5 [mem size 0x00001000]: can't assign; no space > > > > pci 0002:01:00.0: BAR 5 [mem size 0x00001000]: failed to assign > > > > pci 0002:01:00.0: BAR 4 [io size 0x0020]: can't assign; no space > > > > pci 0002:01:00.0: BAR 4 [io size 0x0020]: failed to assign > > > > pci 0002:01:00.0: BAR 5 [mem size 0x00001000]: can't assign; no space > > > > pci 0002:01:00.0: BAR 5 [mem size 0x00001000]: failed to assign > > > > pci 0002:01:00.0: BAR 4 [io size 0x0020]: can't assign; no space > > > > pci 0002:01:00.0: BAR 4 [io size 0x0020]: failed to assign > > > > pci 0002:00:00.0: PCI bridge to [bus 01] > > > > pci 0002:00:00.0: bridge window [mem 0x16000000-0x160fffff 64bit pref] > > > > pci_bus 0002:00: Some PCI device resources are unassigned, try booting > > > > with pci=realloc > > > > pci_bus 0002:00: resource 4 [mem 0x16000000-0x160fffff] > > > > pci_bus 0002:01: resource 2 [mem 0x16000000-0x160fffff 64bit pref] > > > > ... > > > > pci 0002:00:00.0: enabling device (0000 -> 0002) > > > > ahci 0002:01:00.0: probe with driver ahci failed with error -12 > > > > > > > > Bisect points to this patch. Reverting it together with "PCI: Rework > > > > optional resource handling" fixes the problem. For comparison, after > > > > reverting the offending patches, the log messages are as follows. > > > > > > > > pci_bus 0002:00: root bus resource [bus 00-ff] > > > > pci_bus 0002:00: root bus resource [mem 0x16000000-0x160fffff] > > > > pci 0002:00:00.0: [10ee:7021] type 01 class 0x060400 PCIe Root Complex > > > > Integrated Endpoint > > > > pci 0002:00:00.0: PCI bridge to [bus 00] > > > > pci 0002:00:00.0: bridge window [io 0x0000-0x0fff] > > > > pci 0002:00:00.0: bridge window [mem 0x00000000-0x000fffff] > > > > pci 0002:00:00.0: bridge window [mem 0x00000000-0x000fffff 64bit pref] > > > > pci 0002:00:00.0: enabling Extended Tags > > > > pci 0002:00:00.0: bridge configuration invalid ([bus 00-00]), > > > > reconfiguring > > > > pci_bus 0002:01: extended config space not accessible > > > > pci 0002:01:00.0: [8086:2922] type 00 class 0x010601 conventional PCI > > > > endpoint > > > > pci 0002:01:00.0: BAR 4 [io 0x0000-0x001f] > > > > pci 0002:01:00.0: BAR 5 [mem 0x00000000-0x00000fff] > > > > pci 0002:00:00.0: PCI bridge to [bus 01-ff] > > > > pci_bus 0002:01: busn_res: [bus 01-ff] end is updated to 01 > > > > pci 0002:00:00.0: bridge window [mem 0x16000000-0x160fffff]: assigned > > > > pci 0002:00:00.0: bridge window [mem size 0x00100000 64bit pref]: can't > > > > assign; no space > > > > pci 0002:00:00.0: bridge window [mem size 0x00100000 64bit pref]: failed > > > > to assign > > > > pci 0002:00:00.0: bridge window [io size 0x1000]: can't assign; no > > > > space > > > > pci 0002:00:00.0: bridge window [io size 0x1000]: failed to assign > > > > pci 0002:01:00.0: BAR 5 [mem 0x16000000-0x16000fff]: assigned > > > > pci 0002:01:00.0: BAR 4 [io size 0x0020]: can't assign; no space > > > > pci 0002:01:00.0: BAR 4 [io size 0x0020]: failed to assign > > > > pci 0002:00:00.0: PCI bridge to [bus 01] > > > > pci 0002:00:00.0: bridge window [mem 0x16000000-0x160fffff] > > > > pci_bus 0002:00: Some PCI device resources are unassigned, try booting > > > > with pci=realloc > > > > pci_bus 0002:00: resource 4 [mem 0x16000000-0x160fffff] > > > > pci_bus 0002:01: resource 1 [mem 0x16000000-0x160fffff] > > > > ... > > > > pci 0002:00:00.0: enabling device (0000 -> 0002) > > > > ahci 0002:01:00.0: enabling device (0000 -> 0002) > > > > ahci 0002:01:00.0: AHCI vers 0001.0000, 32 command slots, 1.5 Gbps, SATA > > > > mode > > > > ahci 0002:01:00.0: 6/6 ports implemented (port mask 0x3f) > > > > ahci 0002:01:00.0: flags: 64bit ncq only > > > > > > Hi, > > > > > > Thanks for reporting. Please add this to the command line to get the > > > resource releasing between the steps to show: > > > > > > dyndbg="file drivers/pci/setup-bus.c +p" > > > > > > Also, the log snippet just shows it fails but it is impossible to know > > > from it why the resource assigments do not fit so could you please provide > > > a complete dmesg logs. Also providing the contents of /proc/iomem from the > > > working case would save me quite a bit of decoding the iomem layout from > > > the dmesgs. > > > > Hi again, > > > > If you could kindly include this patch into the test with pci_dbg() > > enabled so the resource reset/restore is better tracked. > > > > Same link as before (http://server.roeck-us.net/qemu/mipsel64/). > The log with the patch applied is in bad-extra.log. That log wasn't taken from a bad case but it doesn't matter anymore as I could test this with qemu myself, thanks for providing enough to make it easy to reproduce & test it locally :-). The problem is caused by assign+release cycle being destructive on start aligned resources because successful assigment overwrites the start field. I'll send a patch to fix the problem once I've given it a bit more thought as this resource fitting code is somewhat complex. -- i.
