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Input: zforce_ts - remove unneeded locking

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There is no need to have a lock around calls to i2c_master_send() and
i2c_master_recv() as they are not issued concurrently and they are not
sharing any buffers. Also there is no need for command_mutex as all
commands are issued sequentially.

Remove both.

Tested-by: Andreas Kemnade <andreas@kemnade.info> # Tolino Shine2HD
Link: https://lore.kernel.org/r/20240824055047.1706392-7-dmitry.torokhov@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Dmitry Torokhov
2024-08-23 22:50:30 -07:00
parent 6244559410
commit f388412f70
1 changed files with 9 additions and 38 deletions
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drivers/input/touchscreen/zforce_ts.c
+9 -38
View File
@@ -95,9 +95,7 @@ struct zforce_point {
* @suspending in the process of going to suspend (don't emit wakeup
* events for commands executed to suspend the device)
* @suspended device suspended
* @access_mutex serialize i2c-access, to keep multipart reads together
* @command_done completion to wait for the command result
* @command_mutex serialize commands sent to the ic
* @command_waiting the id of the command that is currently waiting
* for a result
* @command_result returned result of the command
@@ -123,10 +121,7 @@ struct zforce_ts {
u16 version_build;
u16 version_rev;
struct mutex access_mutex;
struct completion command_done;
struct mutex command_mutex;
int command_waiting;
int command_result;
};
@@ -143,9 +138,7 @@ static int zforce_command(struct zforce_ts *ts, u8 cmd)
buf[1] = 1; /* data size, command only */
buf[2] = cmd;
mutex_lock(&ts->access_mutex);
ret = i2c_master_send(client, &buf[0], ARRAY_SIZE(buf));
mutex_unlock(&ts->access_mutex);
if (ret < 0) {
dev_err(&client->dev, "i2c send data request error: %d\n", ret);
return ret;
@@ -169,37 +162,24 @@ static int zforce_send_wait(struct zforce_ts *ts, const char *buf, int len)
struct i2c_client *client = ts->client;
int ret;
ret = mutex_trylock(&ts->command_mutex);
if (!ret) {
dev_err(&client->dev, "already waiting for a command\n");
return -EBUSY;
}
dev_dbg(&client->dev, "sending %d bytes for command 0x%x\n",
buf[1], buf[2]);
ts->command_waiting = buf[2];
mutex_lock(&ts->access_mutex);
ret = i2c_master_send(client, buf, len);
mutex_unlock(&ts->access_mutex);
if (ret < 0) {
dev_err(&client->dev, "i2c send data request error: %d\n", ret);
goto unlock;
return ret;;
}
dev_dbg(&client->dev, "waiting for result for command 0x%x\n", buf[2]);
if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0) {
ret = -ETIME;
goto unlock;
}
if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0)
return -ETIME;
ret = ts->command_result;
unlock:
mutex_unlock(&ts->command_mutex);
return ret;
return 0;
}
static int zforce_command_wait(struct zforce_ts *ts, u8 cmd)
@@ -412,41 +392,35 @@ static int zforce_read_packet(struct zforce_ts *ts, u8 *buf)
struct i2c_client *client = ts->client;
int ret;
mutex_lock(&ts->access_mutex);
/* read 2 byte message header */
ret = i2c_master_recv(client, buf, 2);
if (ret < 0) {
dev_err(&client->dev, "error reading header: %d\n", ret);
goto unlock;
return ret;
}
if (buf[PAYLOAD_HEADER] != FRAME_START) {
dev_err(&client->dev, "invalid frame start: %d\n", buf[0]);
ret = -EIO;
goto unlock;
return -EIO;
}
if (buf[PAYLOAD_LENGTH] == 0) {
dev_err(&client->dev, "invalid payload length: %d\n",
buf[PAYLOAD_LENGTH]);
ret = -EIO;
goto unlock;
return -EIO;
}
/* read the message */
ret = i2c_master_recv(client, &buf[PAYLOAD_BODY], buf[PAYLOAD_LENGTH]);
if (ret < 0) {
dev_err(&client->dev, "error reading payload: %d\n", ret);
goto unlock;
return ret;
}
dev_dbg(&client->dev, "read %d bytes for response command 0x%x\n",
buf[PAYLOAD_LENGTH], buf[PAYLOAD_BODY]);
unlock:
mutex_unlock(&ts->access_mutex);
return ret;
return 0;
}
static void zforce_complete(struct zforce_ts *ts, int cmd, int result)
@@ -801,9 +775,6 @@ static int zforce_probe(struct i2c_client *client)
return -ENOMEM;
}
mutex_init(&ts->access_mutex);
mutex_init(&ts->command_mutex);
ts->client = client;
ts->input = input_dev;