phy: qcom-qusb2: Fix a memory leak on probe

On success nvmem_cell_read() returns a pointer to a dynamically allocated
buffer, and therefore it shall be freed after usage.

The issue is reported by kmemleak:

  # cat /sys/kernel/debug/kmemleak
  unreferenced object 0xffff3b3803e4b280 (size 128):
    comm "kworker/u16:1", pid 107, jiffies 4294892861 (age 94.120s)
    hex dump (first 32 bytes):
      00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
      00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    backtrace:
      [<000000007739afdc>] __kmalloc+0x27c/0x41c
      [<0000000071c0fbf8>] nvmem_cell_read+0x40/0xe0
      [<00000000e803ef1f>] qusb2_phy_init+0x258/0x5bc
      [<00000000fc81fcfa>] phy_init+0x70/0x110
      [<00000000e3d48a57>] dwc3_core_soft_reset+0x4c/0x234
      [<0000000027d1dbd4>] dwc3_core_init+0x68/0x990
      [<000000001965faf9>] dwc3_probe+0x4f4/0x730
      [<000000002f7617ca>] platform_probe+0x74/0xf0
      [<00000000a2576cac>] really_probe+0xc4/0x470
      [<00000000bc77f2c5>] __driver_probe_device+0x11c/0x190
      [<00000000130db71f>] driver_probe_device+0x48/0x110
      [<0000000019f36c2b>] __device_attach_driver+0xa4/0x140
      [<00000000e5812ff7>]  bus_for_each_drv+0x84/0xe0
      [<00000000f4bac574>] __device_attach+0xe4/0x1c0
      [<00000000d3beb631>] device_initial_probe+0x20/0x30
      [<000000008019b9db>] bus_probe_device+0xa4/0xb0

Fixes: ca04d9d3e1b1 ("phy: qcom-qusb2: New driver for QUSB2 PHY on Qcom chips")
Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20210922233548.2150244-1-vladimir.zapolskiy@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/phy/qualcomm/phy-qcom-qusb2.c b/drivers/phy/qualcomm/phy-qcom-qusb2.c
index 7a8e433..032d02b 100644 (file)
--- a/drivers/phy/qualcomm/phy-qcom-qusb2.c
+++ b/drivers/phy/qualcomm/phy-qcom-qusb2.c
@@ -561,7 +561,7 @@ static void qusb2_phy_set_tune2_param(struct qusb2_phy *qphy)
 {
        struct device *dev = &qphy->phy->dev;
        const struct qusb2_phy_cfg *cfg = qphy->cfg;
-       u8 *val;
+       u8 *val, hstx_trim;
 
        /* efuse register is optional */
        if (!qphy->cell)
@@ -575,7 +575,13 @@ static void qusb2_phy_set_tune2_param(struct qusb2_phy *qphy)
         * set while configuring the phy.
         */
        val = nvmem_cell_read(qphy->cell, NULL);
-       if (IS_ERR(val) || !val[0]) {
+       if (IS_ERR(val)) {
+               dev_dbg(dev, "failed to read a valid hs-tx trim value\n");
+               return;
+       }
+       hstx_trim = val[0];
+       kfree(val);
+       if (!hstx_trim) {
                dev_dbg(dev, "failed to read a valid hs-tx trim value\n");
                return;
        }
@@ -583,12 +589,10 @@ static void qusb2_phy_set_tune2_param(struct qusb2_phy *qphy)
        /* Fused TUNE1/2 value is the higher nibble only */
        if (cfg->update_tune1_with_efuse)
                qusb2_write_mask(qphy->base, cfg->regs[QUSB2PHY_PORT_TUNE1],
-                                val[0] << HSTX_TRIM_SHIFT,
-                                HSTX_TRIM_MASK);
+                                hstx_trim << HSTX_TRIM_SHIFT, HSTX_TRIM_MASK);
        else
                qusb2_write_mask(qphy->base, cfg->regs[QUSB2PHY_PORT_TUNE2],
-                                val[0] << HSTX_TRIM_SHIFT,
-                                HSTX_TRIM_MASK);
+                                hstx_trim << HSTX_TRIM_SHIFT, HSTX_TRIM_MASK);
 }
 
 static int qusb2_phy_set_mode(struct phy *phy,