[PATCH v6 12/13] spi: spidev_test: print TX on error

[Jonas Rebmann]

From: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>

If sending an spi message fails, dump its first up to 256 bytes to the
console.

Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Signed-off-by: Jonas Rebmann <jre@xxxxxxxxxxxxxx>
---
 tools/spi/spidev_test.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/tools/spi/spidev_test.c b/tools/spi/spidev_test.c
index cce6669d3789..2295daa37b63 100644
--- a/tools/spi/spidev_test.c
+++ b/tools/spi/spidev_test.c
@@ -194,8 +194,18 @@ static void transfer(int fd, uint8_t const * const tx, uint8_t const * const rx,
 
 	ret = ioctl(fd, SPI_IOC_MESSAGE(effective_transfers), tr);
 	free(tr);
-	if (ret < 0)
+	if (ret < 0) {
+		const size_t dump_len = min_t(size_t, len, 256);
+		int saved_errno = errno;
+
+		if (tx) {
+			hex_dump(tx, dump_len, 32, "TX");
+			if (len > dump_len)
+				printf("... (%zu more bytes)\n", len - dump_len);
+		}
+		errno = saved_errno;
 		pabort("can't send spi message");
+	}
 
 	if (verbose && tx)
 		hex_dump(tx, len, 32, "TX");

-- 
2.56.0.rc0.108.gf0ef1b96a0