Re: [PATCH v2] usb: dwc3: xilinx: make sure pipe clock is deselected in usb2 only mode

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 11/18/24 16:08, Radhey Shyam Pandey wrote:
From: Neal Frager <neal.frager@xxxxxxx>

When the USB3 PHY is not defined in the Linux device tree, there could
still be a case where there is a USB3 PHY is active on the board and

2nd "is " should be dropped. This sounds a bit confusing to me as the PHY is on-chip on zynqmp, maybe you are referring to a reference clock input to the PS-GTR instead?


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@xxxxxxxxxxxxxxx
Signed-off-by: Neal Frager <neal.frager@xxxxxxx>
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@xxxxxxx>
---
Changes for v2:
- Add stable@xxxxxxxxxxxxxxx in CC.

Other than that looks good, thanks.

Acked-by: Peter Korsgaard <peter@xxxxxxxxxxxxx>


---
  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 e3738e1610db..a33a42ba0249 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)) {

base-commit: 744cf71b8bdfcdd77aaf58395e068b7457634b2c

--
Bye, Peter Korsgaard





[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux