iio: adc: mcp3422: fix locking on error path

[ Upstream commit a139ffa40f0c24b753838b8ef3dcf6ad10eb7854 ]

Reading from the chip should be unlocked on error path else the lock
could never being released.

Fixes: 07914c84ba ("iio: adc: Add driver for Microchip MCP3422/3/4 high resolution ADC")
Fixes: 3f1093d83d71 ("iio: adc: mcp3422: fix locking scope")
Acked-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Signed-off-by: Angelo Compagnucci <angelo.compagnucci@gmail.com>
Link: https://lore.kernel.org/r/20200901093218.1500845-1-angelo.compagnucci@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Angelo Compagnucci 2020-09-01 11:32:18 +02:00 committed by Greg Kroah-Hartman
parent 4e8bf9d2ba
commit 4fea86da6a

View File

@ -146,8 +146,10 @@ static int mcp3422_read_channel(struct mcp3422 *adc,
config &= ~MCP3422_PGA_MASK;
config |= MCP3422_PGA_VALUE(adc->pga[req_channel]);
ret = mcp3422_update_config(adc, config);
if (ret < 0)
if (ret < 0) {
mutex_unlock(&adc->lock);
return ret;
}
msleep(mcp3422_read_times[MCP3422_SAMPLE_RATE(adc->config)]);
}