[U-Boot] [PATCH][NEXT] hwmon: do not init sensors on startup

Wolfgang Denk
2010-12-09T14:26:43Z

Dear Heiko Schocher,

In message <1291903238-29071-1-git-send-email-hs@denx.de> you wrote:
>
> --- a/common/cmd_dtt.c
> +++ b/common/cmd_dtt.c
> @@ -28,6 +28,8 @@
> #include <dtt.h>
> #include <i2c.h>
>
> +static unsigned long sensors_init_done = 0;

What if there are more then 32 sensors?

> int do_dtt (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
> {
> int i;
> @@ -42,8 +44,16 @@ int do_dtt (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
> * Loop through sensors, read
> * temperature, and output it.
> */
> - for (i = 0; i < sizeof (sensors); i++)
> - printf ("DTT%d: %i C\n", i + 1, dtt_get_temp (sensors[i]));
> + for (i = 0; i < sizeof (sensors); i++) {
> + if ((sensors_init_done & (1 << i)) != (1 << i)) {
> + if (dtt_init_one(sensors[i]) == 0)
> + sensors_init_done |= (1 << i);
> + else
> + printf("DTT%d: Failed init!\n", i);
> + }
> + if ((sensors_init_done & (1 << i)) == (1 << i))
> + printf ("DTT%d: %i C\n", i + 1, dtt_get_temp(sensors[i]));
> + }

This is overly complicated, it seems. Why not:

for (i = 0; i < sizeof(sensors); i++) {
if ((sensors_init_done & (1 << i)) == 0) {
if (dtt_init_one(sensors[i]) != 0) {
printf("DTT%d: init failed\n", i);
continue;
}
sensors_init_done |= (1 << i);
}

printf("DTT%d: %i C\n", i + 1, dtt_get_temp(sensors[i]));
}

Best regards,

Wolfgang Denk

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