phy: qcom-qusb2: Fix crash if nvmem cell not specified

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@codeaurora.org>
Reviewed-by: Evan Green <evgreen@chromium.org>
Cc: stable <stable@vger.kernel.org> # 4.14+
Signed-off-by: Manu Gautam <mgautam@codeaurora.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

diff --git a/drivers/phy/qualcomm/phy-qcom-qusb2.c b/drivers/phy/qualcomm/phy-qcom-qusb2.c
index 94afeac1a19ef8b8dc8efa24b9f0049c238121e4..40fdef8b5b7526953f2e1cb5eff2196abd9df365 100644 (file)
--- a/drivers/phy/qualcomm/phy-qcom-qusb2.c
+++ b/drivers/phy/qualcomm/phy-qcom-qusb2.c
@@ -315,6 +315,10 @@ static void qusb2_phy_set_tune2_param(struct qusb2_phy *qphy)
        const struct qusb2_phy_cfg *cfg = qphy->cfg;
        u8 *val;
 
+       /* efuse register is optional */
+       if (!qphy->cell)
+               return;
+
        /*
         * Read efuse register having TUNE2/1 parameter's high nibble.
         * If efuse register shows value as 0x0, or if we fail to find