The external calibration coefficients of the RX power are big-endian floats in page A2h. They are read by casting the byte buffer to a 32-bit pointer, which is an unaligned access if the buffer is not 4-byte aligned.
The telemetry command always decodes a buffer from calloc(), but an application may pass any buffer once the decoders are exposed. Read the value with memcpy() and convert it with rte_be_to_cpu_32(). Signed-off-by: Roman Khromenok <[email protected]> --- v3: new patch lib/ethdev/sff_8472.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/lib/ethdev/sff_8472.c b/lib/ethdev/sff_8472.c index f58eba9d2d..cdb6ef1f7e 100644 --- a/lib/ethdev/sff_8472.c +++ b/lib/ethdev/sff_8472.c @@ -4,6 +4,9 @@ */ #include <stdio.h> +#include <string.h> + +#include <rte_byteorder.h> #include "sff_common.h" @@ -126,7 +129,7 @@ static struct sff_8472_aw_flags { /* RXPWR(x) are IEEE-754 floating point numbers in big-endian format */ #define A2_OFFSET_TO_RXPWRx(offset) \ - (befloattoh((const uint32_t *)(data + SFF_A2_BASE + (offset)))) + (befloattoh(data + SFF_A2_BASE + (offset))) /* * 2-byte internal temperature conversions: @@ -169,14 +172,17 @@ static void sff_8472_dom_parse(const uint8_t *data, struct sff_diags *sd) } /* Converts to a float from a big-endian 4-byte source buffer. */ -static float befloattoh(const uint32_t *source) +static float befloattoh(const uint8_t *source) { union { uint32_t src; float dst; } converter; + rte_be32_t be; - converter.src = ntohl(*source); + /* the source may be unaligned */ + memcpy(&be, source, sizeof(be)); + converter.src = rte_be_to_cpu_32(be); return converter.dst; } -- 2.47.3
