4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Manu Gautam <mgautam@xxxxxxxxxxxxxx> commit 0b4555e776ba0712c6fafb98b226b21fd05d2427 upstream. Driver currently crashes due to NULL pointer deference while updating PHY tune register if nvmem cell is NULL. Since, fused value for Tune1/2 register is optional, we'd rather bail out. Fixes: ca04d9d3e1b1 ("phy: qcom-qusb2: New driver for QUSB2 PHY on Qcom chips") Reviewed-by: Vivek Gautam <vivek.gautam@xxxxxxxxxxxxxx> Reviewed-by: Evan Green <evgreen@xxxxxxxxxxxx> Cc: stable <stable@xxxxxxxxxxxxxxx> # 4.14+ Signed-off-by: Manu Gautam <mgautam@xxxxxxxxxxxxxx> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/phy/qualcomm/phy-qcom-qusb2.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/phy/qualcomm/phy-qcom-qusb2.c +++ b/drivers/phy/qualcomm/phy-qcom-qusb2.c @@ -178,6 +178,10 @@ static void qusb2_phy_set_tune2_param(st struct device *dev = &qphy->phy->dev; u8 *val; + /* efuse register is optional */ + if (!qphy->cell) + return; + /* * Read efuse register having TUNE2 parameter's high nibble. * If efuse register shows value as 0x0, or if we fail to find