[PATCH 6.18.y 3/3] usb: dwc3: Move GUID programming after PHY initialization

[Sasha Levin <sashal@kernel.org>]

From: Selvarasu Ganesan <selvarasu.g@samsung.com>

[ Upstream commit aad35f9c926ec220b0742af1ada45666ae667956 ]

The Linux Version Code is currently written to the GUID register before
PHY initialization. Certain PHY implementations (such as Synopsys eUSB
PHY performing link_sw_reset) clear the GUID register to its default
value during initialization, causing the kernel version information to
be lost.

Move the GUID register programming to occur after PHY initialization
completes to ensure the Linux version information persists.

Fixes: fa0ea13e9f1c ("usb: dwc3: core: write LINUX_VERSION_CODE to our GUID register")
Cc: stable <stable@kernel.org>
Reported-by: Pritam Manohar Sutar <pritam.sutar@samsung.com>
Signed-off-by: Selvarasu Ganesan <selvarasu.g@samsung.com>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://patch.msgid.link/20260417063314.2359-1-selvarasu.g@samsung.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/dwc3/core.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index c5bec0bd9cb10..a1f99c3b5f378 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1339,12 +1339,6 @@ static int dwc3_core_init(struct dwc3 *dwc)
 
 	hw_mode = DWC3_GHWPARAMS0_MODE(dwc->hwparams.hwparams0);
 
-	/*
-	 * Write Linux Version Code to our GUID register so it's easy to figure
-	 * out which kernel version a bug was found.
-	 */
-	dwc3_writel(dwc, DWC3_GUID, LINUX_VERSION_CODE);
-
 	ret = dwc3_phy_setup(dwc);
 	if (ret)
 		return ret;
@@ -1376,6 +1370,12 @@ static int dwc3_core_init(struct dwc3 *dwc)
 	if (ret)
 		goto err_exit_phy;
 
+	/*
+	 * Write Linux Version Code to our GUID register so it's easy to figure
+	 * out which kernel version a bug was found.
+	 */
+	dwc3_writel(dwc, DWC3_GUID, LINUX_VERSION_CODE);
+
 	dwc3_core_setup_global_control(dwc);
 	dwc3_core_num_eps(dwc);
 
-- 
2.53.0