[PATCH 4.14 15/36] phy: qcom-qusb2: Fix crash if nvmem cell not specified

From: Greg Kroah-Hartman
Date: Thu Jun 14 2018 - 10:35:50 EST

4.14-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