[PATCH v6 08/10] PCI: dw-rockchip: Set broken L1SS resume flag

[Sebastian Reichel]

Setup the broken_l1ss_resume flag, so that pci_suspend_retains_context()
returns false on the Rockchip platform allowing PCIe peripheral device
drivers to act upon.

Signed-off-by: Sebastian Reichel <sebastian.reichel at collabora.com>
---
 drivers/pci/controller/dwc/pcie-dw-rockchip.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-dw-rockchip.c b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
index 17530507e41b..47d9cab909bc 100644
--- a/drivers/pci/controller/dwc/pcie-dw-rockchip.c
+++ b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
@@ -458,6 +458,21 @@ static int rockchip_pcie_host_init(struct dw_pcie_rp *pp)
 	return 0;
 }
 
+static void rockchip_pcie_host_post_init(struct dw_pcie_rp *pp)
+{
+	/*
+	 * During system suspend, the Rockchip RC driver effectively powers off
+	 * the controller. If the link is in L1SS and the endpoint asserts
+	 * CLKREQ# to exit L1SS, the time required to wake the system and
+	 * restore the PHY/REFCLK may exceed the L1SS exit timing
+	 * (L10_REFCLK_ON + T_COMMONMODE), resulting in Link Down (LDn) and a
+	 * reset of the endpoint. Set this flag to indicate this limitation to
+	 * client drivers so that they can avoid relying on device state being
+	 * preserved during system suspend.
+	 */
+	pp->bridge->broken_l1ss_resume = true;
+}
+
 static void rockchip_pcie_pme_turn_off(struct dw_pcie_rp *pp)
 {
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
@@ -497,6 +512,7 @@ static void rockchip_pcie_pme_turn_off(struct dw_pcie_rp *pp)
 
 static const struct dw_pcie_host_ops rockchip_pcie_host_ops = {
 	.init = rockchip_pcie_host_init,
+	.post_init = rockchip_pcie_host_post_init,
 	.pme_turn_off = rockchip_pcie_pme_turn_off,
 };
 

-- 
2.53.0