| Message ID | 20180731084322.25473-1-oohall@gmail.com |
|---|---|
| State | Accepted |
| Headers | show |
| Series | pci: Clarify power down logic | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | master/apply_patch Successfully applied |
| snowpatch_ozlabs/make_check | success | Test make_check on branch master |
"Oliver O'Halloran" <oohall@gmail.com> writes: > Currently pci_scan_bus() unconditionally calls pci_slot_set_power_state() > when it's finished scanning a bus. This is one of those things that > makes you go "WHAT?" when you first see it and frankly the skiboot PCI > code could do with less of that. > > Signed-off-by: Oliver O'Halloran <oohall@gmail.com> > --- > core/pci.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) Not being something that makes you go "WHAT?" is totally against a bunch of our PCI code, but I'll make an exception this time :) Merged to master as of 7a311b9dec275522d3479e019354913553b1f5bc
diff --git a/core/pci.c b/core/pci.c index 5ec7dabd94eb..cd196b5ab26b 100644 --- a/core/pci.c +++ b/core/pci.c @@ -406,8 +406,10 @@ static void pci_slot_set_power_state(struct phb *phb, if (state == PCI_SLOT_POWER_OFF) { /* Bail if there're something connected */ - if (!list_empty(&pd->children)) + if (!list_empty(&pd->children)) { + PCIERR(phb, pd->bdfn, "Attempted to power off slot with attached devices!\n"); return; + } pci_slot_add_flags(slot, PCI_SLOT_FLAG_BOOTUP); rc = slot->ops.get_power_state(slot, &cur_state); @@ -920,7 +922,9 @@ uint8_t pci_scan_bus(struct phb *phb, uint8_t bus, uint8_t max_bus, pci_cfg_write8(phb, pd->bdfn, PCI_CFG_SUBORDINATE_BUS, max_sub); next_bus = max_sub + 1; - pci_slot_set_power_state(phb, pd, PCI_SLOT_POWER_OFF); + /* power off the slot if there's nothing below it */ + if (list_empty(&pd->children)) + pci_slot_set_power_state(phb, pd, PCI_SLOT_POWER_OFF); } return max_sub;
Currently pci_scan_bus() unconditionally calls pci_slot_set_power_state() when it's finished scanning a bus. This is one of those things that makes you go "WHAT?" when you first see it and frankly the skiboot PCI code could do with less of that. Signed-off-by: Oliver O'Halloran <oohall@gmail.com> --- core/pci.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)