samsung-laptop: tweak traces

- don't output error when probing features at load
- print the SABI signature if samsung_sabi_init()
  succeed
Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

drivers/platform/x86/samsung-laptop.c

@@ -366,10 +366,11 @@ static int sabi_command(struct samsung_laptop *samsung, u16 command,
 
 	if (debug) {
 		if (in)
-			pr_info("SABI 0x%04x {0x%08x, 0x%08x, 0x%04x, 0x%02x}",
+			pr_info("SABI command:0x%04x "
+				"data:{0x%08x, 0x%08x, 0x%04x, 0x%02x}",
 				command, in->d0, in->d1, in->d2, in->d3);
 		else
-			pr_info("SABI 0x%04x", command);
+			pr_info("SABI command:0x%04x", command);
 	}
 
 	/* enable memory to be able to write to it */
@@ -393,10 +394,17 @@ static int sabi_command(struct samsung_laptop *samsung, u16 command,
 	/* see if the command actually succeeded */
 	complete = readb(samsung->sabi_iface + SABI_IFACE_COMPLETE);
 	iface_data = readb(samsung->sabi_iface + SABI_IFACE_DATA);
-	if (complete != 0xaa || iface_data == 0xff) {
+
+	/* iface_data = 0xFF happens when a command is not known
+	 * so we only add a warning in debug mode since we will
+	 * probably issue some unknown command at startup to find
+	 * out which features are supported */
+	if (complete != 0xaa || (iface_data == 0xff && debug))
 		pr_warn("SABI command 0x%04x failed with"
 			" completion flag 0x%02x and interface data 0x%02x",
 			command, complete, iface_data);
+
+	if (complete != 0xaa || iface_data == 0xff) {
 		ret = -EINVAL;
 		goto exit;
 	}
@@ -409,7 +417,7 @@ static int sabi_command(struct samsung_laptop *samsung, u16 command,
 	}
 
 	if (debug && out) {
-		pr_info("SABI {0x%08x, 0x%08x, 0x%04x, 0x%02x}",
+		pr_info("SABI return data:{0x%08x, 0x%08x, 0x%04x, 0x%02x}",
 			out->d0, out->d1, out->d2, out->d3);
 	}
 
@@ -1370,6 +1378,9 @@ static int __init samsung_sabi_init(struct samsung_laptop *samsung)
 	if (samsung->handle_backlight)
 		check_for_stepping_quirk(samsung);
 
+	pr_info("detected SABI interface: %s\n",
+		samsung->config->test_string);
+
 exit:
 	if (ret)
 		samsung_sabi_exit(samsung);