[PATCH 2/4] PCI: tegra194: Remove unnecessary L1SS disable code

Bjorn Helgaas helgaas at kernel.org
Tue Nov 11 14:16:09 PST 2025


From: Bjorn Helgaas <bhelgaas at google.com>

The DWC core clears the L1 Substates Supported bits unless the driver sets
the "dw_pcie.l1ss_support" flag.

The tegra194 init_host_aspm() sets "dw_pcie.l1ss_support" if the platform
has the "supports-clkreq" DT property.  If "supports-clkreq" is absent,
"dw_pcie.l1ss_support" is not set, and the DWC core will clear the L1
Substates Supported bits.

The tegra194 code to clear the L1 Substates Supported bits is unnecessary,
so remove it.

Signed-off-by: Bjorn Helgaas <bhelgaas at google.com>
---
 drivers/pci/controller/dwc/pcie-tegra194.c | 32 ----------------------
 1 file changed, 32 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 3934757baa30..d5545bf37f81 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -608,24 +608,6 @@ static struct pci_ops tegra_pci_ops = {
 };
 
 #if defined(CONFIG_PCIEASPM)
-static void disable_aspm_l11(struct tegra_pcie_dw *pcie)
-{
-	u32 val;
-
-	val = dw_pcie_readl_dbi(&pcie->pci, pcie->cfg_link_cap_l1sub);
-	val &= ~PCI_L1SS_CAP_ASPM_L1_1;
-	dw_pcie_writel_dbi(&pcie->pci, pcie->cfg_link_cap_l1sub, val);
-}
-
-static void disable_aspm_l12(struct tegra_pcie_dw *pcie)
-{
-	u32 val;
-
-	val = dw_pcie_readl_dbi(&pcie->pci, pcie->cfg_link_cap_l1sub);
-	val &= ~PCI_L1SS_CAP_ASPM_L1_2;
-	dw_pcie_writel_dbi(&pcie->pci, pcie->cfg_link_cap_l1sub, val);
-}
-
 static inline u32 event_counter_prog(struct tegra_pcie_dw *pcie, u32 event)
 {
 	u32 val;
@@ -729,8 +711,6 @@ static void init_debugfs(struct tegra_pcie_dw *pcie)
 				    aspm_state_cnt);
 }
 #else
-static inline void disable_aspm_l12(struct tegra_pcie_dw *pcie) { return; }
-static inline void disable_aspm_l11(struct tegra_pcie_dw *pcie) { return; }
 static inline void init_host_aspm(struct tegra_pcie_dw *pcie) { return; }
 static inline void init_debugfs(struct tegra_pcie_dw *pcie) { return; }
 #endif
@@ -934,12 +914,6 @@ static int tegra_pcie_dw_host_init(struct dw_pcie_rp *pp)
 
 	init_host_aspm(pcie);
 
-	/* Disable ASPM-L1SS advertisement if there is no CLKREQ routing */
-	if (!pcie->supports_clkreq) {
-		disable_aspm_l11(pcie);
-		disable_aspm_l12(pcie);
-	}
-
 	if (!pcie->of_data->has_l1ss_exit_fix) {
 		val = dw_pcie_readl_dbi(pci, GEN3_RELATED_OFF);
 		val &= ~GEN3_RELATED_OFF_GEN3_ZRXDC_NONCOMPL;
@@ -1874,12 +1848,6 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
 
 	init_host_aspm(pcie);
 
-	/* Disable ASPM-L1SS advertisement if there is no CLKREQ routing */
-	if (!pcie->supports_clkreq) {
-		disable_aspm_l11(pcie);
-		disable_aspm_l12(pcie);
-	}
-
 	if (!pcie->of_data->has_l1ss_exit_fix) {
 		val = dw_pcie_readl_dbi(pci, GEN3_RELATED_OFF);
 		val &= ~GEN3_RELATED_OFF_GEN3_ZRXDC_NONCOMPL;
-- 
2.43.0




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