[PATCH] usb: dwc3: qcom: Add support to skip phy management by USB core

[Krishna Kurapati]

DWC3 driver does manage phys itself sufficiently for Qualcomm platforms.
If xhci-skip-phy-init is not set, the HCD core does a phy_init and phy_
exit is done only when roothub is being destroyed. Due to this, during
system suspend in host mode, although phy_exit is done by DWC3 core, the
init_count on phy is never down to zero since HCD core also did an init.
consequently causing phy's exit routine to not be called. Hence, add
support to skip phy management by USB core.

Some Exynos platforms still do rely on USB core for phy_calibrate calls,
hence disable USB core management for Qualcomm platforms only.

Signed-off-by: Krishna Kurapati <krishna.kurapati@xxxxxxxxxxxxxxxx>
---
Initially, a patch was sent adding software_node properties [1]. But it
was causing a bootup issue as mentioned in [2]. Hence a revert was sent
to fix it [3]. This patch uses a different approach as opposed to adding
sofware node properties and was tested on sm8750 mtp.

[1]: https://lore.kernel.org/all/20260723-dwc3-skip-init-quirk-v1-1-97682bb44ebd@xxxxxxxxxxxxxxxx/
[2]: https://lore.kernel.org/all/cbb4ae94-7862-4d91-b01d-0d7f18d49a45@xxxxxxxxxxxx/
[3]: https://lore.kernel.org/all/20260909-xhci-fixes-revert-v1-1-7cc97fa0f307@xxxxxxxxxxxxxxxx/
---
 drivers/usb/dwc3/core.c      | 3 +++
 drivers/usb/dwc3/core.h      | 1 +
 drivers/usb/dwc3/dwc3-qcom.c | 1 +
 drivers/usb/dwc3/glue.h      | 2 ++
 drivers/usb/dwc3/host.c      | 5 ++++-
 5 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index fd5c2cd36c59..d9f4e4109abb 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1694,6 +1694,9 @@ static void dwc3_get_software_properties(struct dwc3 *dwc,
 	if (properties->needs_full_reinit)
 		dwc->needs_full_reinit = true;
 
+	if (properties->skip_phy_init)
+		dwc->skip_phy_init = true;
+
 	dwc->gsbuscfg0_reqinfo = DWC3_GSBUSCFG0_REQINFO_UNSPECIFIED;
 
 	if (properties->gsbuscfg0_reqinfo !=
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 608daeb7ef10..b72869380933 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -1420,6 +1420,7 @@ struct dwc3 {
 	unsigned		wakeup_configured:1;
 	unsigned		suspended:1;
 	unsigned		susphy_state:1;
+	unsigned		skip_phy_init:1;
 
 	u16			imod_interval;
 
diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
index e6b6beb38fcb..5387658dd38d 100644
--- a/drivers/usb/dwc3/dwc3-qcom.c
+++ b/drivers/usb/dwc3/dwc3-qcom.c
@@ -738,6 +738,7 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
 	probe_data.res = &res;
 	probe_data.ignore_clocks_and_resets = true;
 	probe_data.properties = DWC3_DEFAULT_PROPERTIES;
+	probe_data.properties.skip_phy_init = true;
 	ret = dwc3_core_probe(&probe_data);
 	if (ret)  {
 		ret = dev_err_probe(dev, ret, "failed to register DWC3 Core\n");
diff --git a/drivers/usb/dwc3/glue.h b/drivers/usb/dwc3/glue.h
index d738e1739ae0..72c5593e657a 100644
--- a/drivers/usb/dwc3/glue.h
+++ b/drivers/usb/dwc3/glue.h
@@ -14,10 +14,12 @@
  * @gsbuscfg0_reqinfo: Value to be programmed in the GSBUSCFG0.REQINFO field
  * @needs_full_reinit: indicate the controller may not remain power during system
  *			pm and need full initialization
+ * @skip_phy_init: skip xHCI PHY initialization on host init
  */
 struct dwc3_properties {
 	u32 gsbuscfg0_reqinfo;
 	unsigned needs_full_reinit:1;
+	unsigned skip_phy_init:1;
 };
 
 #define DWC3_DEFAULT_PROPERTIES ((struct dwc3_properties){		\
diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
index c5674161b2b0..3fb8be8be590 100644
--- a/drivers/usb/dwc3/host.c
+++ b/drivers/usb/dwc3/host.c
@@ -130,7 +130,7 @@ static int dwc3_host_get_irq(struct dwc3 *dwc)
 
 int dwc3_host_init(struct dwc3 *dwc)
 {
-	struct property_entry	props[6];
+	struct property_entry	props[7];
 	struct platform_device	*xhci;
 	int			ret, irq;
 	int			prop_idx = 0;
@@ -174,6 +174,9 @@ int dwc3_host_init(struct dwc3 *dwc)
 	if (dwc->usb2_lpm_disable)
 		props[prop_idx++] = PROPERTY_ENTRY_BOOL("usb2-lpm-disable");
 
+	if (dwc->skip_phy_init)
+		props[prop_idx++] = PROPERTY_ENTRY_BOOL("xhci-skip-phy-init-quirk");
+
 	/**
 	 * WORKAROUND: dwc3 revisions <=3.00a have a limitation
 	 * where Port Disable command doesn't work.

---
base-commit: 7f69cecb6098fada87b010c911aa736a5af8f679
change-id: 20260914-xhci-skip-phy-init-d0a6bd96b13f

Best regards,
--  
Krishna Kurapati <krishna.kurapati@xxxxxxxxxxxxxxxx>