i2c: Shrink struct i2c_client

This shrinks the size of "struct i2c_client" by 40 bytes:

 - Substantially shrinks the string used to identify the chip type
 - The "flags" don't need to be so big
 - Removes some internal padding

It also adds kerneldoc for that struct, explaining how "name" is really a
chip type identifier; it's otherwise potentially confusing.

Because the I2C_NAME_SIZE symbol was abused for both i2c_client.name
and for i2c_adapter.name, this needed to affect i2c_adapter too.  The
adapters which used that symbol now use the more-obviously-correct
idiom of taking the size of that field.

JD: Shorten i2c_adapter.name from 50 to 48 bytes while we're here, to
avoid wasting space in padding.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

2 files changed, 3 insertions, 2 deletions

diff --git a/drivers/video/intelfb/intelfb_i2c.c b/drivers/video/intelfb/intelfb_i2c.c
index f4ede5f6b588..61e4c8759b23 100644
--- a/drivers/video/intelfb/intelfb_i2c.c
+++ b/drivers/video/intelfb/intelfb_i2c.c
@@ -104,7 +104,8 @@ static int intelfb_setup_i2c_bus(struct intelfb_info *dinfo,
 
         chan->dinfo                                     = dinfo;
         chan->reg                                       = reg;
-        snprintf(chan->adapter.name, I2C_NAME_SIZE, "intelfb %s", name);
+        snprintf(chan->adapter.name, sizeof(chan->adapter.name),
+                 "intelfb %s", name);
         chan->adapter.owner                     = THIS_MODULE;
         chan->adapter.id                        = I2C_HW_B_INTELFB;
         chan->adapter.algo_data         = &chan->algo;
diff --git a/drivers/video/matrox/i2c-matroxfb.c b/drivers/video/matrox/i2c-matroxfb.c
index 5ec718a5fe22..4baab7be58de 100644
--- a/drivers/video/matrox/i2c-matroxfb.c
+++ b/drivers/video/matrox/i2c-matroxfb.c
@@ -111,7 +111,7 @@ static int i2c_bus_reg(struct i2c_bit_adapter* b, struct matrox_fb_info* minfo,
         b->mask.data = data;
         b->mask.clock = clock;
         b->adapter = matrox_i2c_adapter_template;
-        snprintf(b->adapter.name, I2C_NAME_SIZE, name,
+        snprintf(b->adapter.name, sizeof(b->adapter.name), name,
                 minfo->fbcon.node);
         i2c_set_adapdata(&b->adapter, b);
         b->adapter.algo_data = &b->bac;