From a48f744bef9ee74814a9eccb030b02223e48c76c Mon Sep 17 00:00:00 2001 From: Neal Frager Date: Mon, 2 Dec 2024 23:41:51 +0530 Subject: [PATCH] usb: dwc3: xilinx: make sure pipe clock is deselected in usb2 only mode When the USB3 PHY is not defined in the Linux device tree, there could still be a case where there is a USB3 PHY active on the board and enabled by the first stage bootloader. If serdes clock is being used then the USB will fail to enumerate devices in 2.0 only mode. To solve this, make sure that the PIPE clock is deselected whenever the USB3 PHY is not defined and guarantees that the USB2 only mode will work in all cases. Fixes: 9678f3361afc ("usb: dwc3: xilinx: Skip resets and USB3 register settings for USB2.0 mode") Cc: stable@vger.kernel.org Signed-off-by: Neal Frager Signed-off-by: Radhey Shyam Pandey Acked-by: Peter Korsgaard Link: https://lore.kernel.org/r/1733163111-1414816-1-git-send-email-radhey.shyam.pandey@amd.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/dwc3/dwc3-xilinx.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/usb/dwc3/dwc3-xilinx.c b/drivers/usb/dwc3/dwc3-xilinx.c index e3738e1610db2..a33a42ba0249a 100644 --- a/drivers/usb/dwc3/dwc3-xilinx.c +++ b/drivers/usb/dwc3/dwc3-xilinx.c @@ -121,8 +121,11 @@ static int dwc3_xlnx_init_zynqmp(struct dwc3_xlnx *priv_data) * in use but the usb3-phy entry is missing from the device tree. * Therefore, skip these operations in this case. */ - if (!priv_data->usb3_phy) + if (!priv_data->usb3_phy) { + /* Deselect the PIPE Clock Select bit in FPD PIPE Clock register */ + writel(PIPE_CLK_DESELECT, priv_data->regs + XLNX_USB_FPD_PIPE_CLK); goto skip_usb3_phy; + } crst = devm_reset_control_get_exclusive(dev, "usb_crst"); if (IS_ERR(crst)) { -- 2.39.5