By refactoring the command setup code, we can let the compiler
determine the size of each command.
Signed-off-by: Marc Gonzalez <[email protected]>
---
drivers/media/dvb-frontends/si2168.c | 142 ++++++++-------------------
1 file changed, 41 insertions(+), 101 deletions(-)
diff --git a/drivers/media/dvb-frontends/si2168.c b/drivers/media/dvb-frontends/si2168.c
index 168c503e9154..19398f041c79 100644
--- a/drivers/media/dvb-frontends/si2168.c
+++ b/drivers/media/dvb-frontends/si2168.c
@@ -11,6 +11,12 @@
static const struct dvb_frontend_ops si2168_ops;
+#define CMD_SETUP(cmd, __args, __rlen) do { \
+ int wlen = sizeof(__args) - 1; \
+ memcpy(cmd.args, __args, wlen); \
+ cmd.wlen = wlen; cmd.rlen = __rlen; \
+} while (0)
+
/* execute firmware command */
static int si2168_cmd_execute(struct i2c_client *client, struct si2168_cmd *cmd)
{
@@ -83,15 +89,13 @@ static int si2168_ts_bus_ctrl(struct dvb_frontend *fe, int acquire)
dev_dbg(&client->dev, "%s acquire: %d\n", __func__, acquire);
/* set TS_MODE property */
- memcpy(cmd.args, "\x14\x00\x01\x10\x10\x00", 6);
+ CMD_SETUP(cmd, "\x14\x00\x01\x10\x10\x00", 4);
if (acquire)
cmd.args[4] |= dev->ts_mode;
else
cmd.args[4] |= SI2168_TS_TRISTATE;
if (dev->ts_clock_gapped)
cmd.args[4] |= 0x40;
- cmd.wlen = 6;
- cmd.rlen = 4;
ret = si2168_cmd_execute(client, &cmd);
return ret;
@@ -115,19 +119,13 @@ static int si2168_read_status(struct dvb_frontend *fe, enum fe_status *status)
switch (c->delivery_system) {
case SYS_DVBT:
- memcpy(cmd.args, "\xa0\x01", 2);
- cmd.wlen = 2;
- cmd.rlen = 13;
+ CMD_SETUP(cmd, "\xa0\x01", 13);
break;
case SYS_DVBC_ANNEX_A:
- memcpy(cmd.args, "\x90\x01", 2);
- cmd.wlen = 2;
- cmd.rlen = 9;
+ CMD_SETUP(cmd, "\x90\x01", 9);
break;
case SYS_DVBT2:
- memcpy(cmd.args, "\x50\x01", 2);
- cmd.wlen = 2;
- cmd.rlen = 14;
+ CMD_SETUP(cmd, "\x50\x01", 14);
break;
default:
ret = -EINVAL;
@@ -164,9 +162,7 @@ static int si2168_read_status(struct dvb_frontend *fe, enum fe_status *status)
/* BER */
if (*status & FE_HAS_VITERBI) {
- memcpy(cmd.args, "\x82\x00", 2);
- cmd.wlen = 2;
- cmd.rlen = 3;
+ CMD_SETUP(cmd, "\x82\x00", 3);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
@@ -197,9 +193,7 @@ static int si2168_read_status(struct dvb_frontend *fe, enum fe_status *status)
/* UCB */
if (*status & FE_HAS_SYNC) {
- memcpy(cmd.args, "\x84\x01", 2);
- cmd.wlen = 2;
- cmd.rlen = 3;
+ CMD_SETUP(cmd, "\x84\x01", 3);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
@@ -285,22 +279,18 @@ static int si2168_set_frontend(struct dvb_frontend *fe)
goto err;
}
- memcpy(cmd.args, "\x88\x02\x02\x02\x02", 5);
- cmd.wlen = 5;
- cmd.rlen = 5;
+ CMD_SETUP(cmd, "\x88\x02\x02\x02\x02", 5);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
/* that has no big effect */
if (c->delivery_system == SYS_DVBT)
- memcpy(cmd.args, "\x89\x21\x06\x11\xff\x98", 6);
+ CMD_SETUP(cmd, "\x89\x21\x06\x11\xff\x98", 3);
else if (c->delivery_system == SYS_DVBC_ANNEX_A)
- memcpy(cmd.args, "\x89\x21\x06\x11\x89\xf0", 6);
+ CMD_SETUP(cmd, "\x89\x21\x06\x11\x89\xf0", 3);
else if (c->delivery_system == SYS_DVBT2)
- memcpy(cmd.args, "\x89\x21\x06\x11\x89\x20", 6);
- cmd.wlen = 6;
- cmd.rlen = 3;
+ CMD_SETUP(cmd, "\x89\x21\x06\x11\x89\x20", 3);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
@@ -317,103 +307,77 @@ static int si2168_set_frontend(struct dvb_frontend *fe)
goto err;
}
- memcpy(cmd.args, "\x51\x03", 2);
- cmd.wlen = 2;
- cmd.rlen = 12;
+ CMD_SETUP(cmd, "\x51\x03", 12);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
- memcpy(cmd.args, "\x12\x08\x04", 3);
- cmd.wlen = 3;
- cmd.rlen = 3;
+ CMD_SETUP(cmd, "\x12\x08\x04", 3);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
- memcpy(cmd.args, "\x14\x00\x0c\x10\x12\x00", 6);
- cmd.wlen = 6;
- cmd.rlen = 4;
+ CMD_SETUP(cmd, "\x14\x00\x0c\x10\x12\x00", 4);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
- memcpy(cmd.args, "\x14\x00\x06\x10\x24\x00", 6);
- cmd.wlen = 6;
- cmd.rlen = 4;
+ CMD_SETUP(cmd, "\x14\x00\x06\x10\x24\x00", 4);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
- memcpy(cmd.args, "\x14\x00\x07\x10\x00\x24", 6);
- cmd.wlen = 6;
- cmd.rlen = 4;
+ CMD_SETUP(cmd, "\x14\x00\x07\x10\x00\x24", 4);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
- memcpy(cmd.args, "\x14\x00\x0a\x10\x00\x00", 6);
+ CMD_SETUP(cmd, "\x14\x00\x0a\x10\x00\x00", 4);
cmd.args[4] = delivery_system | bandwidth;
if (dev->spectral_inversion)
cmd.args[5] |= 1;
- cmd.wlen = 6;
- cmd.rlen = 4;
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
/* set DVB-C symbol rate */
if (c->delivery_system == SYS_DVBC_ANNEX_A) {
- memcpy(cmd.args, "\x14\x00\x02\x11", 4);
+ CMD_SETUP(cmd, "\x14\x00\x02\x11\x00\x00", 4);
cmd.args[4] = ((c->symbol_rate / 1000) >> 0) & 0xff;
cmd.args[5] = ((c->symbol_rate / 1000) >> 8) & 0xff;
- cmd.wlen = 6;
- cmd.rlen = 4;
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
}
- memcpy(cmd.args, "\x14\x00\x0f\x10\x10\x00", 6);
- cmd.wlen = 6;
- cmd.rlen = 4;
+ CMD_SETUP(cmd, "\x14\x00\x0f\x10\x10\x00", 4);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
- memcpy(cmd.args, "\x14\x00\x09\x10\xe3\x08", 6);
+ CMD_SETUP(cmd, "\x14\x00\x09\x10\xe3\x08", 4);
cmd.args[5] |= dev->ts_clock_inv ? 0x00 : 0x10;
- cmd.wlen = 6;
- cmd.rlen = 4;
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
- memcpy(cmd.args, "\x14\x00\x08\x10\xd7\x05", 6);
+ CMD_SETUP(cmd, "\x14\x00\x08\x10\xd7\x05", 4);
cmd.args[5] |= dev->ts_clock_inv ? 0x00 : 0x10;
- cmd.wlen = 6;
- cmd.rlen = 4;
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
- memcpy(cmd.args, "\x14\x00\x01\x12\x00\x00", 6);
- cmd.wlen = 6;
- cmd.rlen = 4;
+ CMD_SETUP(cmd, "\x14\x00\x01\x12\x00\x00", 4);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
- memcpy(cmd.args, "\x14\x00\x01\x03\x0c\x00", 6);
- cmd.wlen = 6;
- cmd.rlen = 4;
+ CMD_SETUP(cmd, "\x14\x00\x01\x03\x0c\x00", 4);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
- memcpy(cmd.args, "\x85", 1);
- cmd.wlen = 1;
- cmd.rlen = 1;
+ CMD_SETUP(cmd, "\x85", 1);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
@@ -443,26 +407,20 @@ static int si2168_init(struct dvb_frontend *fe)
dev_dbg(&client->dev, "\n");
/* initialize */
- memcpy(cmd.args, "\xc0\x12\x00\x0c\x00\x0d\x16\x00\x00\x00\x00\x00\x00", 13);
- cmd.wlen = 13;
- cmd.rlen = 0;
+ CMD_SETUP(cmd, "\xc0\x12\x00\x0c\x00\x0d\x16\x00\x00\x00\x00\x00\x00", 0);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
if (dev->warm) {
/* resume */
- memcpy(cmd.args, "\xc0\x06\x08\x0f\x00\x20\x21\x01", 8);
- cmd.wlen = 8;
- cmd.rlen = 1;
+ CMD_SETUP(cmd, "\xc0\x06\x08\x0f\x00\x20\x21\x01", 1);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
udelay(100);
- memcpy(cmd.args, "\x85", 1);
- cmd.wlen = 1;
- cmd.rlen = 1;
+ CMD_SETUP(cmd, "\x85", 1);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
@@ -471,9 +429,7 @@ static int si2168_init(struct dvb_frontend *fe)
}
/* power up */
- memcpy(cmd.args, "\xc0\x06\x01\x0f\x00\x20\x20\x01", 8);
- cmd.wlen = 8;
- cmd.rlen = 1;
+ CMD_SETUP(cmd, "\xc0\x06\x01\x0f\x00\x20\x20\x01", 1);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
@@ -541,17 +497,13 @@ static int si2168_init(struct dvb_frontend *fe)
release_firmware(fw);
- memcpy(cmd.args, "\x01\x01", 2);
- cmd.wlen = 2;
- cmd.rlen = 1;
+ CMD_SETUP(cmd, "\x01\x01", 1);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
/* query firmware version */
- memcpy(cmd.args, "\x11", 1);
- cmd.wlen = 1;
- cmd.rlen = 10;
+ CMD_SETUP(cmd, "\x11", 10);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
@@ -609,9 +561,7 @@ static int si2168_sleep(struct dvb_frontend *fe)
if (dev->version > ('B' << 24 | 4 << 16 | 0 << 8 | 11 << 0))
dev->warm = false;
- memcpy(cmd.args, "\x13", 1);
- cmd.wlen = 1;
- cmd.rlen = 0;
+ CMD_SETUP(cmd, "\x13", 0);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
@@ -637,9 +587,7 @@ static int si2168_select(struct i2c_mux_core *muxc, u32 chan)
struct si2168_cmd cmd;
/* open I2C gate */
- memcpy(cmd.args, "\xc0\x0d\x01", 3);
- cmd.wlen = 3;
- cmd.rlen = 0;
+ CMD_SETUP(cmd, "\xc0\x0d\x01", 0);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
@@ -657,9 +605,7 @@ static int si2168_deselect(struct i2c_mux_core *muxc, u32 chan)
struct si2168_cmd cmd;
/* close I2C gate */
- memcpy(cmd.args, "\xc0\x0d\x00", 3);
- cmd.wlen = 3;
- cmd.rlen = 0;
+ CMD_SETUP(cmd, "\xc0\x0d\x00", 0);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err;
@@ -730,25 +676,19 @@ static int si2168_probe(struct i2c_client *client,
mutex_init(&dev->i2c_mutex);
/* Initialize */
- memcpy(cmd.args, "\xc0\x12\x00\x0c\x00\x0d\x16\x00\x00\x00\x00\x00\x00", 13);
- cmd.wlen = 13;
- cmd.rlen = 0;
+ CMD_SETUP(cmd, "\xc0\x12\x00\x0c\x00\x0d\x16\x00\x00\x00\x00\x00\x00", 0);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err_kfree;
/* Power up */
- memcpy(cmd.args, "\xc0\x06\x01\x0f\x00\x20\x20\x01", 8);
- cmd.wlen = 8;
- cmd.rlen = 1;
+ CMD_SETUP(cmd, "\xc0\x06\x01\x0f\x00\x20\x20\x01", 1);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err_kfree;
/* Query chip revision */
- memcpy(cmd.args, "\x02", 1);
- cmd.wlen = 1;
- cmd.rlen = 13;
+ CMD_SETUP(cmd, "\x02", 13);
ret = si2168_cmd_execute(client, &cmd);
if (ret)
goto err_kfree;
--
2.17.1
On 01/07/2019 13:44, Marc Gonzalez wrote:
> By refactoring the command setup code, we can let the compiler
> determine the size of each command.
>
> Signed-off-by: Marc Gonzalez <[email protected]>
> ---
> drivers/media/dvb-frontends/si2168.c | 142 ++++++++-------------------
> 1 file changed, 41 insertions(+), 101 deletions(-)
>
> diff --git a/drivers/media/dvb-frontends/si2168.c b/drivers/media/dvb-frontends/si2168.c
> index 168c503e9154..19398f041c79 100644
> --- a/drivers/media/dvb-frontends/si2168.c
> +++ b/drivers/media/dvb-frontends/si2168.c
> @@ -11,6 +11,12 @@
>
> static const struct dvb_frontend_ops si2168_ops;
>
> +#define CMD_SETUP(cmd, __args, __rlen) do { \
> + int wlen = sizeof(__args) - 1; \
> + memcpy(cmd.args, __args, wlen); \
> + cmd.wlen = wlen; cmd.rlen = __rlen; \
> +} while (0)
> +
I'm planning on sending a v2 where drivers/media/tuners/si2157.c
is refactored the same way. Not sure where to store the macro.
Maybe include/media/dvb_frontend.h ?
Regards.
Hi,
On Mon, Jul 01, 2019 at 01:44:09PM +0200, Marc Gonzalez wrote:
> By refactoring the command setup code, we can let the compiler
> determine the size of each command.
I like the idea, it definitely saves some code.
The conversion also looks correct.
> Signed-off-by: Marc Gonzalez <[email protected]>
> ---
> drivers/media/dvb-frontends/si2168.c | 142 ++++++++-------------------
> 1 file changed, 41 insertions(+), 101 deletions(-)
>
> diff --git a/drivers/media/dvb-frontends/si2168.c b/drivers/media/dvb-frontends/si2168.c
> index 168c503e9154..19398f041c79 100644
> --- a/drivers/media/dvb-frontends/si2168.c
> +++ b/drivers/media/dvb-frontends/si2168.c
> @@ -11,6 +11,12 @@
>
> static const struct dvb_frontend_ops si2168_ops;
>
> +#define CMD_SETUP(cmd, __args, __rlen) do { \
> + int wlen = sizeof(__args) - 1; \
> + memcpy(cmd.args, __args, wlen); \
> + cmd.wlen = wlen; cmd.rlen = __rlen; \
> +} while (0)
It would be nice for casual readers to have a little comment here, that
explains (briefly) what this macro does, and what the arguments mean,
and their types.
Why cmd rather than __cmd? This seems inconsistent.
The wlen local variable can be avoided by a bit of suffling:
#define CMD_SETUP(cmd, __args, __rlen) do { \
cmd.rlen = __rlen; \
cmd.wlen = sizeof(__args) - 1; \
memcpy(cmd.args, __args, cmd.wlen); \
} while (0)
[from the other mail]
> I'm planning on sending a v2 where drivers/media/tuners/si2157.c
> is refactored the same way.
Makes sense.
> Not sure where to store the macro. Maybe include/media/dvb_frontend.h?
Then include/media/dvb_frontend.h would contain information about the
private structs of a few (two) drivers. This doesn't seem like a good
idea to me.
Greetings,
Jonathan Neuschäfer
On 02/07/2019 11:51, Jonathan Neuschäfer wrote:
> On Mon, Jul 01, 2019 at 01:44:09PM +0200, Marc Gonzalez wrote:
>
>> By refactoring the command setup code, we can let the compiler
>> determine the size of each command.
>
> I like the idea, it definitely saves some code.
>
> The conversion also looks correct.
>
>> Signed-off-by: Marc Gonzalez <[email protected]>
>> ---
>> drivers/media/dvb-frontends/si2168.c | 142 ++++++++-------------------
>> 1 file changed, 41 insertions(+), 101 deletions(-)
>>
>> diff --git a/drivers/media/dvb-frontends/si2168.c b/drivers/media/dvb-frontends/si2168.c
>> index 168c503e9154..19398f041c79 100644
>> --- a/drivers/media/dvb-frontends/si2168.c
>> +++ b/drivers/media/dvb-frontends/si2168.c
>> @@ -11,6 +11,12 @@
>>
>> static const struct dvb_frontend_ops si2168_ops;
>>
>> +#define CMD_SETUP(cmd, __args, __rlen) do { \
>> + int wlen = sizeof(__args) - 1; \
>> + memcpy(cmd.args, __args, wlen); \
>> + cmd.wlen = wlen; cmd.rlen = __rlen; \
>> +} while (0)
>
> It would be nice for casual readers to have a little comment here, that
> explains (briefly) what this macro does, and what the arguments mean,
> and their types.
Just a bit of background.
A macro is required /at some point/ because arrays "decay" into pointers
when used as function arguments.
Come to think of it, I'm really not a fan of "large" macro functions.
I'll outline a different option in v2.
> Why cmd rather than __cmd? This seems inconsistent.
Note: I hate using underscores in macro argument names, but they clashed
with the struct field names. There was no such clash for 'cmd'.
> The wlen local variable can be avoided by a bit of suffling:
>
> #define CMD_SETUP(cmd, __args, __rlen) do { \
> cmd.rlen = __rlen; \
> cmd.wlen = sizeof(__args) - 1; \
> memcpy(cmd.args, __args, cmd.wlen); \
> } while (0)
Do you think it is important to avoid a local variable?
>> Not sure where to store the macro. Maybe include/media/dvb_frontend.h?
>
> Then include/media/dvb_frontend.h would contain information about the
> private structs of a few (two) drivers. This doesn't seem like a good
> idea to me.
You're right. I found a better place.
Regards.
On 03/07/2019 14:47, Marc Gonzalez wrote:
> Come to think of it, I'm really not a fan of "large" macro functions.
> I'll outline a different option in v2.
My idea is to use a trivial helper function to assign the 3 struct fields,
and then a trivial macro to invoke the helper:
static void cmd_setup(struct si2168_cmd *cmd, char *args, int wlen, int rlen)
{
memcpy(cmd->args, args, wlen);
cmd->wlen = wlen;
cmd->rlen = rlen;
}
#define CMD_SETUP(cmd, args, rlen) \
cmd_setup(cmd, args, sizeof(args) - 1, rlen)
I think this way addresses all of your comments:
- since we're using a real function, the compiler can perform type-checking,
and the function's prototype is self-documenting.
- no more funky __args and __rlen arguments
- no local variables
Note however, that drivers/media/tuners/si2157.c uses a different struct
(struct si2157_cmd). Therefore, if we wanted to apply the same changes
to si2157.c, we would have to define a common struct, and replace all
the uses of struct si2157_cmd and struct si2168_cmd. That seemed too
invasive to do without the maintainer's approval and guidance.
Antti, do you Ack this new approach?
It's not clear what HW is supported by drivers/media/dvb-frontends/si21xx.c
(that's a very generic name).
Regards.
Hi again,
On Wed, Jul 03, 2019 at 02:47:59PM +0200, Marc Gonzalez wrote:
> On 02/07/2019 11:51, Jonathan Neuschäfer wrote:
> > On Mon, Jul 01, 2019 at 01:44:09PM +0200, Marc Gonzalez wrote:
[...]
> >> static const struct dvb_frontend_ops si2168_ops;
> >>
> >> +#define CMD_SETUP(cmd, __args, __rlen) do { \
> >> + int wlen = sizeof(__args) - 1; \
> >> + memcpy(cmd.args, __args, wlen); \
> >> + cmd.wlen = wlen; cmd.rlen = __rlen; \
> >> +} while (0)
> >
> > It would be nice for casual readers to have a little comment here, that
> > explains (briefly) what this macro does, and what the arguments mean,
> > and their types.
>
> Just a bit of background.
>
> A macro is required /at some point/ because arrays "decay" into pointers
> when used as function arguments.
*nod*
[ I should have been more specific: By "here" I meant at that spot in
the code, and by casual readers I mostly meant casual readers of the
code once it's merged. ]
> Come to think of it, I'm really not a fan of "large" macro functions.
> I'll outline a different option in v2.
The v2 approach looks nicer to me, thanks.
> > Why cmd rather than __cmd? This seems inconsistent.
>
> Note: I hate using underscores in macro argument names, but they clashed
> with the struct field names. There was no such clash for 'cmd'.
Hmm, ok.
> > The wlen local variable can be avoided by a bit of suffling:
> >
> > #define CMD_SETUP(cmd, __args, __rlen) do { \
> > cmd.rlen = __rlen; \
> > cmd.wlen = sizeof(__args) - 1; \
> > memcpy(cmd.args, __args, cmd.wlen); \
> > } while (0)
>
> Do you think it is important to avoid a local variable?
Not exactly important, but wlen would be another name that can collide
with the name spaces of the functions where the macro is used and
trigger -Wshadow.
Greetings,
Jonathan Neuschäfer