On Thu, Jan 27, 2022 at 04:15:00PM -0600, Robert Hancock wrote:

A previous patch to skip part of the initialization when a USB3 PHY was not present could result in the return value being uninitialized in that case, causing spurious probe failures. Initialize ret to 0 to avoid this.

Fixes: 9678f3361afc ("usb: dwc3: xilinx: Skip resets and USB3 register settings for USB2.0 mode") Cc: stable@vger.kernel.org Signed-off-by: Robert Hancock robert.hancock@calian.com

Reviewed-by: Nathan Chancellor nathan@kernel.org

This resolves a clang warning that is now in mainline:

$ make -sj"$(nproc)" ARCH=arm64 LLVM=1 allmodconfig drivers/usb/dwc3/dwc3-xilinx.o drivers/usb/dwc3/dwc3-xilinx.c:122:6: error: variable 'ret' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized] if (!usb3_phy) ^~~~~~~~~ drivers/usb/dwc3/dwc3-xilinx.c:216:9: note: uninitialized use occurs here return ret; ^~~ drivers/usb/dwc3/dwc3-xilinx.c:122:2: note: remove the 'if' if its condition is always false if (!usb3_phy) ^~~~~~~~~~~~~~ drivers/usb/dwc3/dwc3-xilinx.c:102:11: note: initialize the variable 'ret' to silence this warning int ret; ^ = 0 1 error generated.

It might be worth moving the initialization into the if statement

if (!usb3_phy) { ret = 0; goto skip_usb3_phy; }

as that will avoid hiding warnings of this nature if someone forgets to set ret on an error path but that is ultimately up to the maintainer.

---

drivers/usb/dwc3/dwc3-xilinx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/dwc3-xilinx.c b/drivers/usb/dwc3/dwc3-xilinx.c index e14ac15e24c3..a6f3a9b38789 100644 --- a/drivers/usb/dwc3/dwc3-xilinx.c +++ b/drivers/usb/dwc3/dwc3-xilinx.c @@ -99,7 +99,7 @@ static int dwc3_xlnx_init_zynqmp(struct dwc3_xlnx *priv_data) struct device *dev = priv_data->dev; struct reset_control *crst, *hibrst, *apbrst; struct phy *usb3_phy;

• int ret;

• int ret = 0; u32 reg;

usb3_phy = devm_phy_optional_get(dev, "usb3-phy"); -- 2.31.1