[PATCH] PCI: rockchip-host: Enable async probe by default

[Igor Velkov via B4 Relay]

From: Igor Velkov <iav at iav.lv>

The probe waits for the link to come up, and with an empty slot it
holds the deferred-probe worker for about 0.7 s. On ROCK Pi 4 with
UHS-I enabled for the SD card, the I/O-domain driver then binds only
after the card has switched to 1.8 V, and tuning fails ("All phases
bad!").

Probe asynchronously, as commit c0e1eb441b1d ("PCI: qcom: Enable async
probe by default") does for the Qualcomm host driver. This does not
order the I/O domain before dw_mmc in general; an explicit dependency
was proposed in [1] and not merged.

Link: https://lore.kernel.org/all/20230904115816.1237684-1-s.hauer@pengutronix.de/ [1]
Signed-off-by: Igor Velkov <iav at iav.lv>
---
Tested on v7.3.1 with the Armbian rockchip64 config (PCIE_ROCKCHIP_HOST=y):
- ROCK Pi 4A, empty slot, UHS-I DT change posted separately: SDR104 on
  3 of 3 cold boots; without this patch tuning fails.
- Kobol Helios64, JMB585 in the slot: link, SATA and disk reads OK
  over 3 cold boots and a reboot.
---
 drivers/pci/controller/pcie-rockchip-host.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/pci/controller/pcie-rockchip-host.c b/drivers/pci/controller/pcie-rockchip-host.c
index 5b071bdc4f90..1e1556e436b8 100644
--- a/drivers/pci/controller/pcie-rockchip-host.c
+++ b/drivers/pci/controller/pcie-rockchip-host.c
@@ -1027,6 +1027,7 @@ static struct platform_driver rockchip_pcie_driver = {
 		.name = "rockchip-pcie",
 		.of_match_table = rockchip_pcie_of_match,
 		.pm = &rockchip_pcie_pm_ops,
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
 	},
 	.probe = rockchip_pcie_probe,
 	.remove = rockchip_pcie_remove,

---
base-commit: 6628e7d4c6b25c8d18f1345e3a20d21829aae7e4
change-id: 20261103-rockchip-pcie-async-42c1c3863617

Best regards,
-- 
Igor Velkov <iav at iav.lv>