Re: [PATCH 28/33] Input: egalax_ts - Drop unnecessary call to i2c_set_clientdata and other changes

On Wed, Jan 18, 2017 at 11:31:54AM -0800, Dmitry Torokhov wrote:

On Wed, Jan 18, 2017 at 09:46:49AM -0800, Guenter Roeck wrote:

quoted

There is no call to i2c_get_clientdata() or dev_get_drvdata().
Drop the unnecessary call to i2c_set_clientdata().
Other relevant changes:
  Simplify error return
  Drop error messages after memory allocation failures

This conversion was done automatically with coccinelle using the
following semantic patches. The semantic patches and the scripts
used to generate this commit log are available at
https://github.com/groeck/coccinelle-patches

- Drop unused variables
- Drop unnecessary braces around conditional return statements
- Drop error message after devm_kzalloc() failure
- Replace 'if (e) return e; return 0;' with 'return e;'
- Drop i2c_set_clientdata()

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/input/touchscreen/egalax_ts.c | 21 ++++-----------------
 1 file changed, 4 insertions(+), 17 deletions(-)

diff --git a/drivers/input/touchscreen/egalax_ts.c b/drivers/input/touchscreen/egalax_ts.c
index 1afc08b08155..05ba1a6dc7fc 100644
--- a/drivers/input/touchscreen/egalax_ts.c
+++ b/drivers/input/touchscreen/egalax_ts.c

@@ -82,10 +82,9 @@ static irqreturn_t egalax_ts_interrupt(int irq, void *dev_id)
 	if (ret < 0)
 		return IRQ_HANDLED;
 
-	if (buf[0] != REPORT_MODE_MTTOUCH) {
+	if (buf[0] != REPORT_MODE_MTTOUCH)
 		/* ignore mouse events and vendor events */
 		return IRQ_HANDLED;
-	}

These are not unnecessary braces, as there are more than 1 line. I.e.
comments are counted along statements, at least by myself. Also, if
there is a single statement spanning several lines I also prefer to have
braces around it.

Makes sense, and agreed. I'll have to figure out how to tell coccinelle about
situations like this.

quoted

 
 	state = buf[1];
 	x = (buf[3] << 8) | buf[2];

@@ -155,13 +154,8 @@ static int egalax_wake_up_device(struct i2c_client *client)
 static int egalax_firmware_version(struct i2c_client *client)
 {
 	static const u8 cmd[MAX_I2C_DATA_LEN] = { 0x03, 0x03, 0xa, 0x01, 0x41 };
-	int ret;
-
-	ret = i2c_master_send(client, cmd, MAX_I2C_DATA_LEN);
-	if (ret < 0)
-		return ret;
 
-	return 0;
+	return i2c_master_send(client, cmd, MAX_I2C_DATA_LEN);

This is not an equivalent transformation, as now callers need to check
for negative return value instead of non-zero. i2c_master_send() returns
number of bytes written on success.

Oops, yes. Excellent point. I am way too agressive here. Thanks for pointing
this out.

Thanks,
Guenter