From: Vidya Sagar <vidyas@nvidia.com>
LTR message should be sent as soon as the root port enables LTR in the
endpoint. Set snoop & no snoop LTR timing and LTR message request before
PCIe links up. This ensures that LTR message is sent upstream as soon as
LTR is enabled.
Fixes: c57247f940e8 ("PCI: tegra: Add support for PCIe endpoint mode in Tegra194")
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
---
V5:
* None
V4:
* None
V3:
* None
V2:
* None
drivers/pci/controller/dwc/pcie-tegra194.c | 15 ++++++---------
1 file changed, 6 insertions(+), 9 deletions(-)
diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 0f669933b108..9883d14f7f97 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -124,6 +124,7 @@
#define APPL_LTR_MSG_1 0xC4
#define LTR_MSG_REQ BIT(15)
+#define LTR_MST_NO_SNOOP_SHIFT 16
#define LTR_NOSNOOP_MSG_REQ BIT(31)
#define APPL_LTR_MSG_2 0xC8
@@ -488,15 +489,6 @@ static irqreturn_t tegra_pcie_ep_irq_thread(int irq, void *arg)
if (val & PCI_COMMAND_MASTER) {
ktime_t timeout;
- /* 110us for both snoop and no-snoop */
- val = FIELD_PREP(PCI_LTR_VALUE_MASK, 110) |
- FIELD_PREP(PCI_LTR_SCALE_MASK, 2) |
- LTR_MSG_REQ |
- FIELD_PREP(PCI_LTR_NOSNOOP_VALUE, 110) |
- FIELD_PREP(PCI_LTR_NOSNOOP_SCALE, 2) |
- LTR_NOSNOOP_MSG_REQ;
- appl_writel(pcie, val, APPL_LTR_MSG_1);
-
/* Send LTR upstream */
val = appl_readl(pcie, APPL_LTR_MSG_2);
val |= APPL_LTR_MSG_2_LTR_MSG_REQ_STATE;
@@ -1799,6 +1791,11 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
val |= APPL_INTR_EN_L1_0_0_RDLH_LINK_UP_INT_EN;
appl_writel(pcie, val, APPL_INTR_EN_L1_0_0);
+ /* 110us for both snoop and no-snoop */
+ val = 110 | (2 << PCI_LTR_SCALE_SHIFT) | LTR_MSG_REQ;
+ val |= (val << LTR_MST_NO_SNOOP_SHIFT);
+ appl_writel(pcie, val, APPL_LTR_MSG_1);
+
reset_control_deassert(pcie->core_rst);
/* Perform cleanup that requires refclk and core reset deasserted */
--
2.34.1