Try a quick read from the device in mip4_query_device() to make sure
that the device is there, as we do not consider failures to retrieve
product name or resolution fatal.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---
drivers/input/touchscreen/melfas_mip4.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/drivers/input/touchscreen/melfas_mip4.c b/drivers/input/touchscreen/melfas_mip4.c
index 703d7f983d0a..05108c2fea93 100644
--- a/drivers/input/touchscreen/melfas_mip4.c
+++ b/drivers/input/touchscreen/melfas_mip4.c
@@ -253,10 +253,21 @@ static int mip4_get_fw_version(struct mip4_ts *ts)
*/
static int mip4_query_device(struct mip4_ts *ts)
{
+ union i2c_smbus_data dummy;
int error;
u8 cmd[2];
u8 buf[14];
+ /*
+ * Make sure there is something at this address as we do not
+ * consider subsequent failures as fatal.
+ */
+ if (i2c_smbus_xfer(ts->client->adapter, ts->client->addr,
+ 0, I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &dummy) < 0) {
+ dev_err(&ts->client->dev, "nothing at this address\n");
+ return -ENXIO;
+ }
+
/* Product name */
cmd[0] = MIP4_R0_INFO;
cmd[1] = MIP4_R1_INFO_PRODUCT_NAME;
--
2.12.1.578.ge9c3154ca4-goog
--
Dmitry
--
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