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

[Alex Hung]

On 04/28/2014 09:35 AM, 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: Alex Hung <alex.hung at canonical.com>