[RFC PATCH 3/3] WIP: PCI: rockchip: add remove() support

Brian Norris
2017-03-08T23:39:33Z

*** THIS IS WIP; DO NOT MERGE ***

I haven't quite figured out the right way to invert pci_remap_iospace().
I guess no one supports this yet? So currently, if you try to
remove/re-probe we'll hit a BUG() in ioremap code when we call this a
second time.

I post the unfinished work here as a bug report, so that if I can't get
this cleaned up quickly, we should instead prevent unbinding the device
once it's probed.

***

Currently, if we try to unbind the platform device, the remove will
succeed, but the removal won't undo most of the registration, leaving
partially-configured PCI devices in the system.

This allows, for example, a simple 'lspci' to crash the system, as it
will try to touch the freed (via devm_*) driver structures.

Signed-off-by: Brian Norris <briannorris@chromium.org>
---
drivers/pci/host/pcie-rockchip.c | 30 +++++++++++++++++++++++++++++-
1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/host/pcie-rockchip.c b/drivers/pci/host/pcie-rockchip.c
index 5d7b27b1e941..e111b3bf63ca 100644
--- a/drivers/pci/host/pcie-rockchip.c
+++ b/drivers/pci/host/pcie-rockchip.c
@@ -225,6 +225,7 @@ struct rockchip_pcie {
struct irq_domain *irq_domain;
u32 io_size;
int offset;
+ struct pci_bus *root_bus;
phys_addr_t io_bus_addr;
void __iomem *msg_region;
u32 mem_size;
@@ -1391,6 +1392,7 @@ static int rockchip_pcie_probe(struct platform_device *pdev)
err = -ENOMEM;
goto err_free_res;
}
+ rockchip->root_bus = bus;

pci_bus_size_bridges(bus);
pci_bus_assign_resources(bus);
@@ -1421,6 +1423,32 @@ static int rockchip_pcie_probe(struct platform_device *pdev)
return err;
}

+static int rockchip_pcie_remove(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct rockchip_pcie *rockchip = dev_get_drvdata(dev);
+
+ pci_stop_root_bus(rockchip->root_bus);
+ pci_remove_root_bus(rockchip->root_bus);
+
+ phy_power_off(rockchip->phy);
+ phy_exit(rockchip->phy);
+
+ clk_disable_unprepare(rockchip->clk_pcie_pm);
+ clk_disable_unprepare(rockchip->hclk_pcie);
+ clk_disable_unprepare(rockchip->aclk_perf_pcie);
+ clk_disable_unprepare(rockchip->aclk_pcie);
+
+ if (!IS_ERR(rockchip->vpcie3v3))
+ regulator_disable(rockchip->vpcie3v3);
+ if (!IS_ERR(rockchip->vpcie1v8))
+ regulator_disable(rockchip->vpcie1v8);
+ if (!IS_ERR(rockchip->vpcie0v9))
+ regulator_disable(rockchip->vpcie0v9);
+
+ return 0;
+}
+
static const struct dev_pm_ops rockchip_pcie_pm_ops = {
SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(rockchip_pcie_suspend_noirq,
rockchip_pcie_resume_noirq)
@@ -1438,6 +1466,6 @@ static struct platform_driver rockchip_pcie_driver = {
.pm = &rockchip_pcie_pm_ops,
},
.probe = rockchip_pcie_probe,
-
+ .remove = rockchip_pcie_remove,
};
builtin_platform_driver(rockchip_pcie_driver);
--
2.12.0.246.ga2ecc84866-goog