ACK: [RFC,PATCH 2/7 v2] fwts: Only run firmware detection once

[Colin Ian King]

On 28/04/14 02:35, Jeremy Kerr wrote:
> Store the discovered value in a static var, and return this value on
> subsequent invocations of fwts_firmware_detect.
> 
> Signed-off-by: Jeremy Kerr <jk at ozlabs.org>
> 
> ---
>  src/lib/include/fwts_firmware.h |    2 +-
>  src/lib/src/fwts_firmware.c     |   19 +++++++++++++++----
>  2 files changed, 16 insertions(+), 5 deletions(-)
> 
> diff --git a/src/lib/include/fwts_firmware.h b/src/lib/include/fwts_firmware.h
> index ee3880d..265ef4d 100644
> --- a/src/lib/include/fwts_firmware.h
> +++ b/src/lib/include/fwts_firmware.h
> @@ -21,7 +21,7 @@
>  
>  #include <stdbool.h>
>  
> -enum {
> +enum firmware_type {
>  	FWTS_FIRMWARE_UNKNOWN = 0,
>  	FWTS_FIRMWARE_BIOS = 1,
>  	FWTS_FIRMWARE_UEFI = 2,
> diff --git a/src/lib/src/fwts_firmware.c b/src/lib/src/fwts_firmware.c
> index bf080a7..4b59cef 100644
> --- a/src/lib/src/fwts_firmware.c
> +++ b/src/lib/src/fwts_firmware.c
> @@ -23,6 +23,9 @@
>  
>  #include "fwts.h"
>  
> +static enum firmware_type firmware_type;
> +static bool firmware_type_valid;
> +
>  /*
>   *  fwts_memory_map_entry_compare()
>   *	callback used to sort memory_map entries on start address
> @@ -31,10 +34,18 @@ int fwts_firmware_detect(void)
>  {
>  	struct stat statbuf;
>  
> -	if (stat("/sys/firmware/efi", &statbuf))
> -		return FWTS_FIRMWARE_BIOS;		/* No UEFI, Assume BIOS */
> -	else
> -		return FWTS_FIRMWARE_UEFI;
> +	if (firmware_type_valid)
> +		return firmware_type;
> +
> +	if (stat("/sys/firmware/efi", &statbuf)) {
> +		/* No UEFI, Assume BIOS */
> +		firmware_type = FWTS_FIRMWARE_BIOS;
> +	} else {
> +		firmware_type = FWTS_FIRMWARE_UEFI;
> +	}
> +
> +	firmware_type_valid = true;
> +	return firmware_type;
>  }
>  
>  int fwts_firmware_features(void)
>
Acked-by: Colin Ian King <colin.king at canonical.com>