Assert PCI Configuration Enable bit after probe. When this bit is left to
0 in the endpoint mode, the RK3399 PCIe endpoint core will generate
configuration request retry status (CRS) messages back to the root complex.
Assert this bit after probe to allow the RK3399 PCIe endpoint core to reply
to configuration requests from the root complex.
This is documented in section 17.5.8.1.2 of the RK3399 TRM.

Fixes: cf590b078391 ("PCI: rockchip: Add EP driver for Rockchip PCIe controller")
Cc: stable@vger.kernel.org
Signed-off-by: Rick Wertenbroek <rick.wertenbroek@gmail.com>
---
 drivers/pci/controller/pcie-rockchip-ep.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/pci/controller/pcie-rockchip-ep.c b/drivers/pci/controller/pcie-rockchip-ep.c
index 9b835377b..4c84e403e 100644
--- a/drivers/pci/controller/pcie-rockchip-ep.c
+++ b/drivers/pci/controller/pcie-rockchip-ep.c
@@ -623,6 +623,8 @@ static int rockchip_pcie_ep_probe(struct platform_device *pdev)
 
 	ep->irq_pci_addr = ROCKCHIP_PCIE_EP_DUMMY_IRQ_ADDR;
 
+	rockchip_pcie_write(rockchip, PCIE_CLIENT_CONF_ENABLE, PCIE_CLIENT_CONFIG);
+
 	return 0;
 err_epc_mem_exit:
 	pci_epc_mem_exit(epc);
-- 
2.25.1

On 2/14/23 23:08, Rick Wertenbroek wrote:
> Assert PCI Configuration Enable bit after probe. When this bit is left to
> 0 in the endpoint mode, the RK3399 PCIe endpoint core will generate
> configuration request retry status (CRS) messages back to the root complex.
> Assert this bit after probe to allow the RK3399 PCIe endpoint core to reply
> to configuration requests from the root complex.
> This is documented in section 17.5.8.1.2 of the RK3399 TRM.
> 
> Fixes: cf590b078391 ("PCI: rockchip: Add EP driver for Rockchip PCIe controller")
> Cc: stable@vger.kernel.org
> Signed-off-by: Rick Wertenbroek <rick.wertenbroek@gmail.com>

Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

-- 
Damien Le Moal
Western Digital Research