[PATCH v2 1/2] PCI: dwc: Perform host_init() before registering msi

From: Bjorn Andersson
Date: Mon Aug 23 2021 - 11:49:17 EST


On the Qualcomm sc8180x platform the bootloader does something related
to PCI that leaves a pending "msi" interrupt, which with the current
ordering often fires before init has a chance to enable the clocks that
are necessary for the interrupt handler to access the hardware.

Move the host_init() call before the registration of the "msi" interrupt
handler to ensure the host driver has a chance to enable the clocks.

The assignment of the bridge's ops and child_ops is moved along, because
at least the TI Keystone driver overwrites these in its host_init
callback.

Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
---

Changes since v1:
- New patch, instead of enabling resources in the qcom driver before jumping to
dw_pcie_host_init(), per Rob Herring's suggestion.

.../pci/controller/dwc/pcie-designware-host.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index d1d9b8344ec9..f4755f3a03be 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -335,6 +335,16 @@ int dw_pcie_host_init(struct pcie_port *pp)
if (pci->link_gen < 1)
pci->link_gen = of_pci_get_max_link_speed(np);

+ /* Set default bus ops */
+ bridge->ops = &dw_pcie_ops;
+ bridge->child_ops = &dw_child_pcie_ops;
+
+ if (pp->ops->host_init) {
+ ret = pp->ops->host_init(pp);
+ if (ret)
+ return ret;
+ }
+
if (pci_msi_enabled()) {
pp->has_msi_ctrl = !(pp->ops->msi_host_init ||
of_property_read_bool(np, "msi-parent") ||
@@ -388,15 +398,6 @@ int dw_pcie_host_init(struct pcie_port *pp)
}
}

- /* Set default bus ops */
- bridge->ops = &dw_pcie_ops;
- bridge->child_ops = &dw_child_pcie_ops;
-
- if (pp->ops->host_init) {
- ret = pp->ops->host_init(pp);
- if (ret)
- goto err_free_msi;
- }
dw_pcie_iatu_detect(pci);

dw_pcie_setup_rc(pp);
--
2.29.2