'struct i2c_algorithm' are not modified in these drivers.

Constifying this structure moves some data to a read-only section, so
increase overall security, especially when the structure holds some
function pointers.

More over, dvb_usb_device_properties->i2c_algo seems to only be copied in
i2c_adapter->algo, which is already a "const struct i2c_algorithm".
This is done in dvb_usb_i2c_init()

On a x86_64, with allmodconfig, as an example:
Before:
======
   text	   data	    bss	    dec	    hex	filename
  30571	   5916	     36	  36523	   8eab	drivers/media/usb/dvb-usb/af9005.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
  30667	   5852	     36	  36555	   8ecb	drivers/media/usb/dvb-usb/af9005.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
--
Compile tested only
---
 drivers/media/usb/dvb-usb/af9005.c         |  2 +-
 drivers/media/usb/dvb-usb/az6027.c         |  2 +-
 drivers/media/usb/dvb-usb/cxusb.c          |  2 +-
 drivers/media/usb/dvb-usb/digitv.c         |  2 +-
 drivers/media/usb/dvb-usb/dtv5100.c        |  2 +-
 drivers/media/usb/dvb-usb/dvb-usb.h        |  2 +-
 drivers/media/usb/dvb-usb/dw2102.c         | 14 +++++++-------
 drivers/media/usb/dvb-usb/m920x.c          |  2 +-
 drivers/media/usb/dvb-usb/opera1.c         |  2 +-
 drivers/media/usb/dvb-usb/pctv452e.c       |  2 +-
 drivers/media/usb/dvb-usb/technisat-usb2.c |  2 +-
 drivers/media/usb/dvb-usb/ttusb2.c         |  2 +-
 12 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/drivers/media/usb/dvb-usb/af9005.c b/drivers/media/usb/dvb-usb/af9005.c
index 13604e6acdb8..30e615958293 100644
--- a/drivers/media/usb/dvb-usb/af9005.c
+++ b/drivers/media/usb/dvb-usb/af9005.c
@@ -445,7 +445,7 @@ static u32 af9005_i2c_func(struct i2c_adapter *adapter)
 	return I2C_FUNC_I2C;
 }
 
-static struct i2c_algorithm af9005_i2c_algo = {
+static const struct i2c_algorithm af9005_i2c_algo = {
 	.master_xfer = af9005_i2c_xfer,
 	.functionality = af9005_i2c_func,
 };
diff --git a/drivers/media/usb/dvb-usb/az6027.c b/drivers/media/usb/dvb-usb/az6027.c
index 2bc27710427d..03dd40e3833e 100644
--- a/drivers/media/usb/dvb-usb/az6027.c
+++ b/drivers/media/usb/dvb-usb/az6027.c
@@ -1062,7 +1062,7 @@ static u32 az6027_i2c_func(struct i2c_adapter *adapter)
 	return I2C_FUNC_I2C;
 }
 
-static struct i2c_algorithm az6027_i2c_algo = {
+static const struct i2c_algorithm az6027_i2c_algo = {
 	.master_xfer   = az6027_i2c_xfer,
 	.functionality = az6027_i2c_func,
 };
diff --git a/drivers/media/usb/dvb-usb/cxusb.c b/drivers/media/usb/dvb-usb/cxusb.c
index 1d98d3465e28..5b80320501f5 100644
--- a/drivers/media/usb/dvb-usb/cxusb.c
+++ b/drivers/media/usb/dvb-usb/cxusb.c
@@ -287,7 +287,7 @@ static u32 cxusb_i2c_func(struct i2c_adapter *adapter)
 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 }
 
-static struct i2c_algorithm cxusb_i2c_algo = {
+static const struct i2c_algorithm cxusb_i2c_algo = {
 	.master_xfer   = cxusb_i2c_xfer,
 	.functionality = cxusb_i2c_func,
 };
diff --git a/drivers/media/usb/dvb-usb/digitv.c b/drivers/media/usb/dvb-usb/digitv.c
index 32134be16914..57df884931c4 100644
--- a/drivers/media/usb/dvb-usb/digitv.c
+++ b/drivers/media/usb/dvb-usb/digitv.c
@@ -88,7 +88,7 @@ static u32 digitv_i2c_func(struct i2c_adapter *adapter)
 	return I2C_FUNC_I2C;
 }
 
-static struct i2c_algorithm digitv_i2c_algo = {
+static const struct i2c_algorithm digitv_i2c_algo = {
 	.master_xfer   = digitv_i2c_xfer,
 	.functionality = digitv_i2c_func,
 };
diff --git a/drivers/media/usb/dvb-usb/dtv5100.c b/drivers/media/usb/dvb-usb/dtv5100.c
index 56c9d521a34a..a960186479db 100644
--- a/drivers/media/usb/dvb-usb/dtv5100.c
+++ b/drivers/media/usb/dvb-usb/dtv5100.c
@@ -97,7 +97,7 @@ static u32 dtv5100_i2c_func(struct i2c_adapter *adapter)
 	return I2C_FUNC_I2C;
 }
 
-static struct i2c_algorithm dtv5100_i2c_algo = {
+static const struct i2c_algorithm dtv5100_i2c_algo = {
 	.master_xfer   = dtv5100_i2c_xfer,
 	.functionality = dtv5100_i2c_func,
 };
diff --git a/drivers/media/usb/dvb-usb/dvb-usb.h b/drivers/media/usb/dvb-usb/dvb-usb.h
index cbb0541d4dc1..9f7a897b33ea 100644
--- a/drivers/media/usb/dvb-usb/dvb-usb.h
+++ b/drivers/media/usb/dvb-usb/dvb-usb.h
@@ -309,7 +309,7 @@ struct dvb_usb_device_properties {
 		struct dvb_rc core;
 	} rc;
 
-	struct i2c_algorithm *i2c_algo;
+	const struct i2c_algorithm *i2c_algo;
 
 	int generic_bulk_ctrl_endpoint;
 	int generic_bulk_ctrl_endpoint_response;
diff --git a/drivers/media/usb/dvb-usb/dw2102.c b/drivers/media/usb/dvb-usb/dw2102.c
index 79e2ccf974c9..ec9e0cfaf581 100644
--- a/drivers/media/usb/dvb-usb/dw2102.c
+++ b/drivers/media/usb/dvb-usb/dw2102.c
@@ -839,37 +839,37 @@ static u32 dw210x_i2c_func(struct i2c_adapter *adapter)
 	return I2C_FUNC_I2C;
 }
 
-static struct i2c_algorithm dw2102_i2c_algo = {
+static const struct i2c_algorithm dw2102_i2c_algo = {
 	.master_xfer = dw2102_i2c_transfer,
 	.functionality = dw210x_i2c_func,
 };
 
-static struct i2c_algorithm dw2102_serit_i2c_algo = {
+static const struct i2c_algorithm dw2102_serit_i2c_algo = {
 	.master_xfer = dw2102_serit_i2c_transfer,
 	.functionality = dw210x_i2c_func,
 };
 
-static struct i2c_algorithm dw2102_earda_i2c_algo = {
+static const struct i2c_algorithm dw2102_earda_i2c_algo = {
 	.master_xfer = dw2102_earda_i2c_transfer,
 	.functionality = dw210x_i2c_func,
 };
 
-static struct i2c_algorithm dw2104_i2c_algo = {
+static const struct i2c_algorithm dw2104_i2c_algo = {
 	.master_xfer = dw2104_i2c_transfer,
 	.functionality = dw210x_i2c_func,
 };
 
-static struct i2c_algorithm dw3101_i2c_algo = {
+static const struct i2c_algorithm dw3101_i2c_algo = {
 	.master_xfer = dw3101_i2c_transfer,
 	.functionality = dw210x_i2c_func,
 };
 
-static struct i2c_algorithm s6x0_i2c_algo = {
+static const struct i2c_algorithm s6x0_i2c_algo = {
 	.master_xfer = s6x0_i2c_transfer,
 	.functionality = dw210x_i2c_func,
 };
 
-static struct i2c_algorithm su3000_i2c_algo = {
+static const struct i2c_algorithm su3000_i2c_algo = {
 	.master_xfer = su3000_i2c_transfer,
 	.functionality = dw210x_i2c_func,
 };
diff --git a/drivers/media/usb/dvb-usb/m920x.c b/drivers/media/usb/dvb-usb/m920x.c
index c88a202daf5f..809f69e90975 100644
--- a/drivers/media/usb/dvb-usb/m920x.c
+++ b/drivers/media/usb/dvb-usb/m920x.c
@@ -319,7 +319,7 @@ static u32 m920x_i2c_func(struct i2c_adapter *adapter)
 	return I2C_FUNC_I2C;
 }
 
-static struct i2c_algorithm m920x_i2c_algo = {
+static const struct i2c_algorithm m920x_i2c_algo = {
 	.master_xfer   = m920x_i2c_xfer,
 	.functionality = m920x_i2c_func,
 };
diff --git a/drivers/media/usb/dvb-usb/opera1.c b/drivers/media/usb/dvb-usb/opera1.c
index 268f05fc8691..301b16e33e5f 100644
--- a/drivers/media/usb/dvb-usb/opera1.c
+++ b/drivers/media/usb/dvb-usb/opera1.c
@@ -155,7 +155,7 @@ static u32 opera1_i2c_func(struct i2c_adapter *adapter)
 	return I2C_FUNC_I2C;
 }
 
-static struct i2c_algorithm opera1_i2c_algo = {
+static const struct i2c_algorithm opera1_i2c_algo = {
 	.master_xfer = opera1_i2c_xfer,
 	.functionality = opera1_i2c_func,
 };
diff --git a/drivers/media/usb/dvb-usb/pctv452e.c b/drivers/media/usb/dvb-usb/pctv452e.c
index 2aab49003493..3ec1c9a14d93 100644
--- a/drivers/media/usb/dvb-usb/pctv452e.c
+++ b/drivers/media/usb/dvb-usb/pctv452e.c
@@ -906,7 +906,7 @@ static struct stb6100_config stb6100_config = {
 };
 
 
-static struct i2c_algorithm pctv452e_i2c_algo = {
+static const struct i2c_algorithm pctv452e_i2c_algo = {
 	.master_xfer   = pctv452e_i2c_xfer,
 	.functionality = pctv452e_i2c_func
 };
diff --git a/drivers/media/usb/dvb-usb/technisat-usb2.c b/drivers/media/usb/dvb-usb/technisat-usb2.c
index df90c6c5f3b9..b36800870024 100644
--- a/drivers/media/usb/dvb-usb/technisat-usb2.c
+++ b/drivers/media/usb/dvb-usb/technisat-usb2.c
@@ -199,7 +199,7 @@ static u32 technisat_usb2_i2c_func(struct i2c_adapter *adapter)
 	return I2C_FUNC_I2C;
 }
 
-static struct i2c_algorithm technisat_usb2_i2c_algo = {
+static const struct i2c_algorithm technisat_usb2_i2c_algo = {
 	.master_xfer   = technisat_usb2_i2c_xfer,
 	.functionality = technisat_usb2_i2c_func,
 };
diff --git a/drivers/media/usb/dvb-usb/ttusb2.c b/drivers/media/usb/dvb-usb/ttusb2.c
index 373ffa7f641e..af80e02b26ee 100644
--- a/drivers/media/usb/dvb-usb/ttusb2.c
+++ b/drivers/media/usb/dvb-usb/ttusb2.c
@@ -434,7 +434,7 @@ static u32 ttusb2_i2c_func(struct i2c_adapter *adapter)
 	return I2C_FUNC_I2C;
 }
 
-static struct i2c_algorithm ttusb2_i2c_algo = {
+static const struct i2c_algorithm ttusb2_i2c_algo = {
 	.master_xfer   = ttusb2_i2c_xfer,
 	.functionality = ttusb2_i2c_func,
 };
-- 
2.46.0