Per PCIe r6.0, sec 6.6.1, software must generally wait a minimum of
100ms (PCIE_RESET_CONFIG_DEVICE_WAIT_MS) after Link training completes
before sending a Configuration Request.
Prior to ec9fd499b9c6 ("PCI: dw-rockchip: Don't wait for link since
we can detect Link Up"), dw-rockchip used dw_pcie_wait_for_link(),
which waited between 0 and 90ms after the link came up before we
enumerate the bus, and this was apparently enough for most devices.
After ec9fd499b9c6, rockchip_pcie_rc_sys_irq_thread() started
enumeration immediately when handling the link-up IRQ, and devices
(e.g., Laszlo Fiat's PLEXTOR PX-256M8PeGN NVMe SSD) may not be ready
to handle config requests yet.
Delay PCIE_RESET_CONFIG_DEVICE_WAIT_MS after the link-up IRQ before
starting enumeration.
Cc: Laszlo Fiat <laszlo.fiat@xxxxxxxxx>
Reviewed-by: Damien Le Moal <dlemoal@xxxxxxxxxx>
Fixes: 0e898eb8df4e ("PCI: rockchip-dwc: Add Rockchip RK356X host controller driver")
Signed-off-by: Niklas Cassel <cassel@xxxxxxxxxx>
---
drivers/pci/controller/dwc/pcie-dw-rockchip.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/pci/controller/dwc/pcie-dw-rockchip.c b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
index 93171a392879..8a068fd4f867 100644
--- a/drivers/pci/controller/dwc/pcie-dw-rockchip.c
+++ b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
@@ -458,6 +458,7 @@ static irqreturn_t rockchip_pcie_rc_sys_irq_thread(int irq, void *arg)
if (reg & PCIE_RDLH_LINK_UP_CHGED) {
if (rockchip_pcie_link_up(pci)) {
+ msleep(PCIE_RESET_CONFIG_DEVICE_WAIT_MS);
dev_dbg(dev, "Received Link up event. Starting enumeration!\n");
/* Rescan the bus to enumerate endpoint devices */
pci_lock_rescan_remove();
--
2.49.0
