[PATCH v3 06/11] PCI: brcmstb: Avoid turn off of bridge reset

Stanimir Varbanov
2024-10-14T14:40:59Z

On PCIe turn off avoid shutdown of bridge reset,
by introducing a quirk flag.

Signed-off-by: Stanimir Varbanov <svarbanov@suse.de>
---
v2 -> v3:
- Added more descriptive comment on CFG_QUIRK_AVOID_BRIDGE_SHUTDOWN quirk.

drivers/pci/controller/pcie-brcmstb.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index b76c16287f37..757a1646d53c 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -234,10 +234,20 @@ struct inbound_win {
u64 cpu_addr;
};

+/*
+ * The RESCAL block is tied to PCIe controller #1, regardless of the number of
+ * controllers, and turning off PCIe controller #1 prevents access to the RESCAL
+ * register blocks, therefore not other controller can access this register
+ * space, and depending upon the bus fabric we may get a timeout (UBUS/GISB),
+ * or a hang (AXI).
+ */
+#define CFG_QUIRK_AVOID_BRIDGE_SHUTDOWN BIT(0)
+
struct pcie_cfg_data {
const int *offsets;
const enum pcie_soc_base soc_base;
const bool has_phy;
+ const u32 quirks;
u8 num_inbound_wins;
int (*perst_set)(struct brcm_pcie *pcie, u32 val);
int (*bridge_sw_init_set)(struct brcm_pcie *pcie, u32 val);
@@ -290,6 +300,7 @@ struct brcm_pcie {
struct subdev_regulators *sr;
bool ep_wakeup_capable;
bool has_phy;
+ u32 quirks;
u8 num_inbound_wins;
};

@@ -1539,8 +1550,9 @@ static int brcm_pcie_turn_off(struct brcm_pcie *pcie)
u32p_replace_bits(&tmp, 1, PCIE_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK);
writel(tmp, base + HARD_DEBUG(pcie));

- /* Shutdown PCIe bridge */
- ret = pcie->bridge_sw_init_set(pcie, 1);
+ if (!(pcie->quirks & CFG_QUIRK_AVOID_BRIDGE_SHUTDOWN))
+ /* Shutdown PCIe bridge */
+ ret = pcie->bridge_sw_init_set(pcie, 1);

return ret;
}
@@ -1854,6 +1866,7 @@ static int brcm_pcie_probe(struct platform_device *pdev)
pcie->perst_set = data->perst_set;
pcie->bridge_sw_init_set = data->bridge_sw_init_set;
pcie->has_phy = data->has_phy;
+ pcie->quirks = data->quirks;
pcie->num_inbound_wins = data->num_inbound_wins;

pcie->base = devm_platform_ioremap_resource(pdev, 0);
--
2.43.0