Re: [PATCH v2] PCI: qcom: Allow L1 and its sub states

From: Krishna Chaitanya Chundru
Date: Fri Jun 24 2022 - 04:02:44 EST


A gentle remainder.

On 6/15/2022 6:45 PM, Krishna chaitanya chundru wrote:
Allow L1 and its sub-states in the qcom pcie driver.
By default this is disabled in the hardware. So enabling it explicitly.

Signed-off-by: Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx>
---
drivers/pci/controller/dwc/pcie-qcom.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 6ab9089..0d8efcc 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -41,6 +41,9 @@
#define L23_CLK_RMV_DIS BIT(2)
#define L1_CLK_RMV_DIS BIT(1)
+#define PCIE20_PARF_PM_CTRL 0x20
+#define REQ_NOT_ENTR_L1 BIT(5)
+
#define PCIE20_PARF_PHY_CTRL 0x40
#define PHY_CTRL_PHY_TX0_TERM_OFFSET_MASK GENMASK(20, 16)
#define PHY_CTRL_PHY_TX0_TERM_OFFSET(x) ((x) << 16)
@@ -1267,6 +1270,11 @@ static int qcom_pcie_init_2_7_0(struct qcom_pcie *pcie)
val |= BIT(4);
writel(val, pcie->parf + PCIE20_PARF_MHI_CLOCK_RESET_CTRL);
+ /* Enable L1 and L1ss */
+ val = readl(pcie->parf + PCIE20_PARF_PM_CTRL);
+ val &= ~REQ_NOT_ENTR_L1;
+ writel(val, pcie->parf + PCIE20_PARF_PM_CTRL);
+
if (IS_ENABLED(CONFIG_PCI_MSI)) {
val = readl(pcie->parf + PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT);
val |= BIT(31);