V2 -- As v1 included the minimal code to fix a regression. v2 does
the same but adds some improvements suggested by Bjorn.
-- In the unlikely but possible case that some other driver
starts using the port driver's dev_data field, do not overwrite
it but issue an error and return.
-- Functions probe() and resume() do similar operations but
did them in a different order; make this order consistent
for both.
-- New commit to remove forward declarations.
-- New commit for only the PCIe config-space access "refusal mode".
-- brcm_pcie_linkup renamed to brcm_pcie_start_link
-- Add '_noirq' to the brcm_pcie_{suspend,resume} function names
to match the dev_pm_ops names.
-- Changes to commit messages:
o Explain why we are splitting a function in two parts.
o s/RB/Root Port/
NOTE for Bjorn: The two commits "add mechanism .." and "add control ..."
would probably be more clear if they were squashed. They are kept
separate as the first one's code may someday be moved under the Port
driver. As such, there's some churn.
NOTE for Bjorn: There is no hurry on Broadcom's side wrt which
release cycle/phase this patchset is applied. It goes in
when you think it is ready.
V1 -- Resubmission of patchset after original was reverted for a
regression.
A submission [1] was made to enable a PCIe root port to turn on
regulators for downstream devices. It was accepted. Months later, a
regression was discovered on an RPi CM4 [2]. The patchset was reverted
[3] as the fix came too late in the release cycle. The regression in
question is triggered only when the PCIe RC DT node has no root port
subnode, which is a perfectly reasonsable configuration.
The original commits are now being resubmitted with some modifications
to fix the regression. The modifcations on the original commits are
described below (the SHA is that of the original commit):
[830aa6f29f07 PCI: brcmstb: Split brcm_pcie_setup() into two funcs]
NOTE: In the originally submitted patchset, this commit introduced a
regression that was corrected by a subsequent commit in the same
patchset. Let's not do this again.
@@ -1411,6 +1411,10 @@ static int brcm_pcie_probe(struct platform_device *pdev)
if (ret)
goto fail;
+ ret = brcm_pcie_linkup(pcie);
+ if (ret)
+ goto fail;
[67211aadcb4b PCI: brcmstb: Add mechanism to turn on subdev regulators]
NOTE: Not related to the regression, the regulators must be freed whenever
the PCIe tree is dismantled:
@@ -507,6 +507,7 @@ static void pci_subdev_regulators_remove_bus(struct pci_bus *bus)
if (regulator_bulk_disable(sr->num_supplies, sr->supplies))
dev_err(dev, "failed to disable regulators for downstream device\n");
+ regulator_bulk_free(sr->num_supplies, sr->supplies);
dev->driver_data = NULL;
[93e41f3fca3d PCI: brcmstb: Add control of subdevice voltage regulators]
NOTE: If the PCIe RC DT node was missing a Root Port subnode, the PCIe
link-up was skipped. This is the regression. Fix it by attempting
link-up even if the Root Port DT subnode is missing.
@@ -503,11 +503,10 @@ static int pci_subdev_regulators_add_bus(struct pci_bus *bus)
static int brcm_pcie_add_bus(struct pci_bus *bus)
{
- struct device *dev = &bus->dev;
struct brcm_pcie *pcie = (struct brcm_pcie *) bus->sysdata;
int ret;
- if (!dev->of_node || !bus->parent || !pci_is_root_bus(bus->parent))
+ if (!bus->parent || !pci_is_root_bus(bus->parent))
return 0;
ret = pci_subdev_regulators_add_bus(bus);
[1] https://lore.kernel.org/r/20220106160332.2143-1-jim2101024@xxxxxxxxx
[2] https://bugzilla.kernel.org/show_bug.cgi?id=215925
[3] https://lore.kernel.org/linux-pci/20220511201856.808690-1-helgaas@xxxxxxxxxx/
Jim Quinlan (6):
PCI: brcmstb: Remove unnecessary forward declarations
PCI: brcmstb: Split brcm_pcie_setup() into two funcs
PCI: brcmstb: Add "refusal mode" to preclude PCIe-induced CPU aborts
PCI: brcmstb: Add mechanism to turn on subdev regulators
PCI: brcmstb: Add control of subdevice voltage regulators
PCI: brcmstb: Do not turn off WOL regulators on suspend
drivers/pci/controller/pcie-brcmstb.c | 438 +++++++++++++++++++-------
1 file changed, 332 insertions(+), 106 deletions(-)
base-commit: c5fe7a97f20c7f3070ac870144515c0fabc6b999
--
2.17.1
