[Pdbg] [PATCH 1/3] istep: Add checking for istep major/minor numbers

[Alistair Popple]

Part of me feels like one day we will need a way of over-riding this (say when 
the SBE decides that istep 5.3 is a thing). Can we just print a warning that 
things may fail instead? From memory the SBE will just respond with an error 
if the wrong numbers are specified anyway, so it shouldn't cause a big issue.

I assume there is no way of probing the SBE to find out what isteps it 
supports? Do you think it would make sense to just keep incrementing until we 
get an invalid argument failure from the SBE?

- Alistair

On Thursday, 4 July 2019 6:11:31 PM AEST Amitay Isaacs wrote:
> Signed-off-by: Amitay Isaacs <amitay at ozlabs.org>
> ---
>  src/istep.c | 30 ++++++++++++++++++++++++++----
>  1 file changed, 26 insertions(+), 4 deletions(-)
> 
> diff --git a/src/istep.c b/src/istep.c
> index 08a6215..a9acbe7 100644
> --- a/src/istep.c
> +++ b/src/istep.c
> @@ -20,18 +20,40 @@
>  #include "optcmd.h"
>  #include "path.h"
> 
> +struct istep_data {
> +	int major;
> +	int minor_first;
> +	int minor_last;
> +} istep_data[] = {
> +	{ 2, 2, 17 },
> +	{ 3, 1, 22 },
> +	{ 4, 1, 34 },
> +	{ 5, 1,  2 },
> +	{ 0, 0, 0  },
> +};
> +
>  static int istep(uint32_t major, uint32_t minor)
>  {
>  	struct pdbg_target *target;
> -	int count = 0;
> +	int count = 0, i;
> 
>  	if (major < 2 || major > 5) {
>  		fprintf(stderr, "Istep major should be 2 to 5\n");
>  		return 0;
>  	}
> -	if (major == 2 && minor == 1) {
> -		fprintf(stderr, "Istep 2 minor should be > 1\n");
> -		return 0;
> +
> +	for (i=0; istep_data[i].major != 0; i++) {
> +		if (istep_data[i].major != major)
> +			continue;
> +
> +		if (minor < istep_data[i].minor_first ||
> +		    minor > istep_data[i].minor_last) {
> +			fprintf(stderr, "Istep %d minor should be %d to %d\n",
> +				major,
> +				istep_data[i].minor_first,
> +				istep_data[i].minor_last);
> +			return 0;
> +		}
>  	}
> 
>  	for_each_path_target_class("sbefifo", target) {