Re: [PATCH v2 8/8] MIPS: pci-legacy: use generic pci_enable_resources

[Guenter Roeck]

On Tue, Apr 13, 2021 at 08:12:40PM -0700, Ilya Lipnitskiy wrote:
> Follow the reasoning from commit 842de40d93e0 ("PCI: add generic
> pci_enable_resources()"):
> 
>   The only functional difference from the MIPS version is that the
>   generic one uses "!r->parent" to check for resource collisions
>   instead of "!r->start && r->end".
> 
> That should have no effect on any pci-legacy driver.
> 

Unfortunately it does. With this patch in place, all my mips qemu emulations
fail to boot from ide/ata drive; the driver is not instantiated. The error
message is:

ata_piix 0000:00:0a.1: can't enable device: BAR 0 [io  0x01f0-0x01f7] not claimed
ata_piix: probe of 0000:00:0a.1 failed with error -22

Reverting this patch fixes the problem, and the message displayed by the driver
is:

ata_piix 0000:00:0a.1: enabling device (0000 -> 0001)

Bisect log is attached.

Guenter

---
# bad: [50b8b1d699ac313c0a07a3c185ffb23aecab8abb] Add linux-next specific files for 20210419
# good: [bf05bf16c76bb44ab5156223e1e58e26dfe30a88] Linux 5.12-rc8
git bisect start 'HEAD' 'v5.12-rc8'
# bad: [c4bb91fc07e59241cde97f913d7a2fbedc248f0d] Merge remote-tracking branch 'crypto/master'
git bisect bad c4bb91fc07e59241cde97f913d7a2fbedc248f0d
# bad: [499f739ad70f2a58aac985dceb25ca7666da88be] Merge remote-tracking branch 'jc_docs/docs-next'
git bisect bad 499f739ad70f2a58aac985dceb25ca7666da88be
# bad: [11b56408a328d1c5c4dfa7667c5dc46956b64aec] Merge remote-tracking branch 'parisc-hd/for-next'
git bisect bad 11b56408a328d1c5c4dfa7667c5dc46956b64aec
# good: [09ccc0ee1227f2cfe50d8dbbe241d115d9b3885f] Merge branch 'arm/defconfig' into for-next
git bisect good 09ccc0ee1227f2cfe50d8dbbe241d115d9b3885f
# good: [a5b76c2f17330e266a5c56dde21430e27b0d0dbb] Merge remote-tracking branch 'arm-soc/for-next'
git bisect good a5b76c2f17330e266a5c56dde21430e27b0d0dbb
# good: [1e4241f6813f1c1a0027d96df075ffd01808b3cf] Merge remote-tracking branch 'ti-k3/ti-k3-next'
git bisect good 1e4241f6813f1c1a0027d96df075ffd01808b3cf
# good: [7496a43be7a362391607d78e49a3f28de80029ce] Merge remote-tracking branch 'h8300/h8300-next'
git bisect good 7496a43be7a362391607d78e49a3f28de80029ce
# good: [66633abd0642f1e89d26e15f36fb13d3a1c535ff] MIPS/bpf: Enable bpf_probe_read{, str}() on MIPS again
git bisect good 66633abd0642f1e89d26e15f36fb13d3a1c535ff
# good: [2c92ef8ff8d327797c1920ae7f938bcc6f3f7421] MIPS: Fix strnlen_user access check
git bisect good 2c92ef8ff8d327797c1920ae7f938bcc6f3f7421
# good: [3a070801c61f4e3987d59b1068368ba71d727208] Merge remote-tracking branch 'microblaze/next'
git bisect good 3a070801c61f4e3987d59b1068368ba71d727208
# good: [317f553bb677e324c9c865ff7f14597bc5ceeb9c] MIPS: pci-legacy: remove redundant info messages
git bisect good 317f553bb677e324c9c865ff7f14597bc5ceeb9c
# bad: [6ce48897ce476bed86fde28752c27596e8753277] MIPS: Loongson64: Add kexec/kdump support
git bisect bad 6ce48897ce476bed86fde28752c27596e8753277
# bad: [99bca615d89510917864fac6b26fd343eff2aba2] MIPS: pci-legacy: use generic pci_enable_resources
git bisect bad 99bca615d89510917864fac6b26fd343eff2aba2
# good: [0af83d2e447af3e5098583cb6320bb1b1fb0976b] MIPS: pci-legacy: remove busn_resource field
git bisect good 0af83d2e447af3e5098583cb6320bb1b1fb0976b
# first bad commit: [99bca615d89510917864fac6b26fd343eff2aba2] MIPS: pci-legacy: use generic pci_enable_resources