[PATCH 3/8] PCI: aardvark: Start link training immediately after enabling link training

From: Pali RohÃr
Date: Wed Apr 15 2020 - 12:02:12 EST


Adding even 100ms (PCI_PM_D3COLD_WAIT) delay between enabling link training
and starting link training cause that some Compex WLE900VX cards are not
detected.

So move code for enabling link training after PCI_PM_D3COLD_WAIT delay.

This change fixes Compex WLE900VX cards detection on Turris MOX after cold
boot.

Fixes: f4c7d053d7f7 ("PCI: aardvark: Wait for endpoint to be ready before
training link")

Signed-off-by: Pali RohÃr <pali@xxxxxxxxxx>
---
drivers/pci/controller/pci-aardvark.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
index ad4f0fa57624..756b31c4d20b 100644
--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -322,11 +322,6 @@ static void advk_pcie_setup_hw(struct advk_pcie *pcie)
reg |= LANE_COUNT_1;
advk_writel(pcie, reg, PCIE_CORE_CTRL0_REG);

- /* Enable link training */
- reg = advk_readl(pcie, PCIE_CORE_CTRL0_REG);
- reg |= LINK_TRAINING_EN;
- advk_writel(pcie, reg, PCIE_CORE_CTRL0_REG);
-
/* Enable MSI */
reg = advk_readl(pcie, PCIE_CORE_CTRL2_REG);
reg |= PCIE_CORE_CTRL2_MSI_ENABLE;
@@ -368,6 +363,16 @@ static void advk_pcie_setup_hw(struct advk_pcie *pcie)
*/
msleep(PCI_PM_D3COLD_WAIT);

+ /*
+ * Do "Enable link training" and "Start link training" in a row without
+ * any delay between them. Adding even 100ms delay (PCI_PM_D3COLD_WAIT)
+ * cause that some Compex WLE900VX cards are not detected.
+ */
+
+ /* Enable link training */
+ reg = advk_readl(pcie, PCIE_CORE_CTRL0_REG);
+ reg |= LINK_TRAINING_EN;
+ advk_writel(pcie, reg, PCIE_CORE_CTRL0_REG);
/* Start link training */
reg = advk_readl(pcie, PCIE_CORE_LINK_CTRL_STAT_REG);
reg |= PCIE_CORE_LINK_TRAINING;
--
2.20.1