Re: [PATCH] ddbridge: constify i2c_algorithm structure

From: Gustavo A. R. Silva
Date: Mon Jul 17 2017 - 00:10:45 EST


Hi Daniel,


On 07/10/2017 10:16 AM, Daniel Scheller wrote:
Am Sun, 9 Jul 2017 20:15:36 -0500
schrieb "Gustavo A. R. Silva" <garsilva@xxxxxxxxxxxxxx>:

Check for i2c_algorithm structures that are only stored in
the algo field of an i2c_adapter structure. This field is
declared const, so i2c_algorithm structures that have this
property can be declared as const also.

This issue was identified using Coccinelle and the following
semantic patch:

@r disable optional_qualifier@
identifier i;
position p;
@@
static struct i2c_algorithm i@p = { ... };

@ok@
identifier r.i;
struct i2c_adapter e;
position p;
@@
e.algo = &i@p;

@bad@
position p != {r.p,ok.p};
identifier r.i;
@@
i@p

@depends on !bad disable optional_qualifier@
identifier r.i;
@@
static
+const
struct i2c_algorithm i = { ... };

Signed-off-by: Gustavo A. R. Silva <garsilva@xxxxxxxxxxxxxx>
---
drivers/media/pci/ddbridge/ddbridge-core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/pci/ddbridge/ddbridge-core.c
b/drivers/media/pci/ddbridge/ddbridge-core.c index cd1723e..9663a4c
100644 --- a/drivers/media/pci/ddbridge/ddbridge-core.c
+++ b/drivers/media/pci/ddbridge/ddbridge-core.c
@@ -200,7 +200,7 @@ static u32 ddb_i2c_functionality(struct
i2c_adapter *adap) return I2C_FUNC_SMBUS_EMUL;
}
-static struct i2c_algorithm ddb_i2c_algo = {
+static const struct i2c_algorithm ddb_i2c_algo = {
.master_xfer = ddb_i2c_master_xfer,
.functionality = ddb_i2c_functionality,
};
Hi Gustavo,
Hi all,

please hold this single one patch from the constify patches back for
now, since we're in the process of bumping the whole driver to a newer
version which involves lots of code shuffling. With this, quite some
GIT rebasing work needs to be done, and adding this one liner at a
later time (thus rebasing it) is way easier.

To be sure this will not be forgotten afterwards, I've already posted a
patch applying the exact change at [1].

Thank you very much!

[1] https://patchwork.linuxtv.org/patch/42393/

Thank you!

--
Gustavo A. R. Silva