iio: imu: adis: protect initial startup routine with state lock

The initial startup routine is called by some ADIS drivers during probe,
and before registering with IIO. Normally, userspace should not be able to
do any access to the device (as there shouldn't be any available).

This change extends the state lock to the entire initial-startup routine.
Behaviourally nothing should change, but this should make the library
function a bit more robust.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/imu/adis.c b/drivers/iio/imu/adis.c
index 615f174f0e6eb624da9a5e071a0f7b29fd7058da..10b8922fd51b61315f77443d14a0bdfd4b27fdff 100644 (file)
--- a/drivers/iio/imu/adis.c
+++ b/drivers/iio/imu/adis.c
@@ -331,7 +331,7 @@ static int adis_self_test(struct adis *adis)
 {
        int ret;
 
-       ret = adis_write_reg_16(adis, adis->data->msc_ctrl_reg,
+       ret = __adis_write_reg_16(adis, adis->data->msc_ctrl_reg,
                        adis->data->self_test_mask);
        if (ret) {
                dev_err(&adis->spi->dev, "Failed to initiate self test: %d\n",
@@ -341,10 +341,10 @@ static int adis_self_test(struct adis *adis)
 
        msleep(adis->data->startup_delay);
 
-       ret = adis_check_status(adis);
+       ret = __adis_check_status(adis);
 
        if (adis->data->self_test_no_autoclear)
-               adis_write_reg_16(adis, adis->data->msc_ctrl_reg, 0x00);
+               __adis_write_reg_16(adis, adis->data->msc_ctrl_reg, 0x00);
 
        return ret;
 }
@@ -362,19 +362,23 @@ int adis_initial_startup(struct adis *adis)
 {
        int ret;
 
+       mutex_lock(&adis->state_lock);
+
        ret = adis_self_test(adis);
        if (ret) {
                dev_err(&adis->spi->dev, "Self-test failed, trying reset.\n");
-               adis_reset(adis);
+               __adis_reset(adis);
                msleep(adis->data->startup_delay);
                ret = adis_self_test(adis);
                if (ret) {
                        dev_err(&adis->spi->dev, "Second self-test failed, giving up.\n");
-                       return ret;
+                       goto out_unlock;
                }
        }
 
-       return 0;
+out_unlock:
+       mutex_unlock(&adis->state_lock);
+       return ret;
 }
 EXPORT_SYMBOL_GPL(adis_initial_startup);