On Mon, 31 Aug 2020 10:27:37 +0100
Marc Zyngier <m...@kernel.org> wrote:
>
> Ah, so actually anything that *enables pcie* kills your system.
> Great investigative work!
>
> >
> > And backed by a further bisection with this that points to
> > d84c572de1a360501d2e439ac632126f5facf59d being the actual change
> > that causes the tablet to fail to boot, as long as the pcie0 node is
> > identified as pci properly.
> >
> > I am unsure if I should add as a Cc everyone involved in that change
> > set, though the author (coincidentally) is already in the original
> > list of recipients.
>
> I've deliberately moved Rob from Cc to To... ;-)
Thanks, I don't actually know who to write to exactly.
> > Any additional thoughts from this additional information?
>
> What you could do is to start looking at which of the
> pci_is_root_bus() changes breaks PCIe on this system. The fact that
> it breaks on your system and not on mine is a bit puzzling.
Let me show you, on top of v5.9-rc3 I can successfully boot using this
partial revert / adaptation of d84c572d. In addition, it also allows
the Wi-Fi to work again, compared to how it didn't in 5.9-rc1 or
5.9-rc[23] with the dumb revert of your fix.
So, if we number each pci_is_root_bus by order appearance, it is only
the second use, in rockchip_pcie_valid_device, which seem to cause
scarlet not to boot.
The patch (not actually a patch submission) reverts only that instance
of pci_is_root_bus, while also doing some leg work to put back some
functionally equivalent code that was refactored away since.
If there's anything else you want me to try, don't hesitate.
---
drivers/pci/controller/pcie-rockchip-host.c | 8 +++++++-
drivers/pci/controller/pcie-rockchip.h | 1 +
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/controller/pcie-rockchip-host.c
b/drivers/pci/controller/pcie-rockchip-host.c
index 0bb2fb3e8a0b..5a27fa833fbd 100644
--- a/drivers/pci/controller/pcie-rockchip-host.c
+++ b/drivers/pci/controller/pcie-rockchip-host.c
@@ -79,7 +79,7 @@ static int rockchip_pcie_valid_device(struct rockchip_pcie
*rockchip,
* do not read more than one device on the bus directly attached
* to RC's downstream side.
*/
- if (pci_is_root_bus(bus->parent) && dev > 0)
+ if (bus->primary == rockchip->root_bus_nr && dev > 0)
return 0;
return 1;
@@ -944,6 +944,7 @@ static int rockchip_pcie_probe(struct platform_device *pdev)
struct rockchip_pcie *rockchip;
struct device *dev = &pdev->dev;
struct pci_host_bridge *bridge;
+ struct resource *bus_res;
int err;
if (!dev->of_node)
@@ -983,6 +984,11 @@ static int rockchip_pcie_probe(struct platform_device
*pdev)
if (err < 0)
goto err_deinit_port;
+ /* HACK; ~equiv to last param of pci_parse_request_of_pci_ranges */
+ bus_res = (resource_list_first_type(&bridge->windows,
IORESOURCE_MEM))->res;
+
+ rockchip->root_bus_nr = bus_res->start;
+
err = rockchip_pcie_cfg_atu(rockchip);
if (err)
goto err_remove_irq_domain;
diff --git a/drivers/pci/controller/pcie-rockchip.h
b/drivers/pci/controller/pcie-rockchip.h
index c7d0178fc8c2..0952fec7e34d 100644
--- a/drivers/pci/controller/pcie-rockchip.h
+++ b/drivers/pci/controller/pcie-rockchip.h
@@ -298,6 +298,7 @@ struct rockchip_pcie {
struct gpio_desc *ep_gpio;
u32 lanes;
u8 lanes_map;
+ u8 root_bus_nr;
int link_gen;
struct device *dev;
struct irq_domain *irq_domain;
--
2.25.4
Thanks again!
--
Samuel Dionne-Riel
