From: Gerhard Sittig <redacted>
Date: Fri, 2 Oct 2020 09:18:57 +0000 (+0200)
Subject: pce-322a: unbreak send_command() return code
X-Git-Url: https://sigrok.org/gitaction?a=commitdiff_plain;h=a4be2b327be8;p=libsigrok.git

pce-322a: unbreak send_command() return code

Data was sent to the serial port, and the non-zero positive write length
was mistaken as an error, since it did not match the SR_OK code's value.
This snuck in with commit 379e95c587e1d in 2017-08.

Rephrase the check for successful serial writes in the pce-322a driver.
Pass on error codes from the serial layer in verbatim form. Check for
the exact expected write length and derive SR_ERR_IO upon mismatch. Do
return SR_OK upon success.

Reported-By: Michael Ströder <redacted>
Tested-By: Michael Ströder <redacted>
---

diff --git a/src/hardware/pce-322a/protocol.c b/src/hardware/pce-322a/protocol.c
index ee637e80..ee98c7c6 100644
--- a/src/hardware/pce-322a/protocol.c
+++ b/src/hardware/pce-322a/protocol.c
@@ -26,6 +26,7 @@ static int send_command(const struct sr_dev_inst *sdi, uint16_t command)
 {
 	struct sr_serial_dev_inst *serial;
 	uint8_t buffer[2];
+	int ret;
 
 	buffer[0] = command >> 8;
 	buffer[1] = command;
@@ -33,13 +34,20 @@ static int send_command(const struct sr_dev_inst *sdi, uint16_t command)
 	if (!(serial = sdi->conn))
 		return SR_ERR;
 
-	return serial_write_blocking(serial, (const void *)buffer, 2, 0);
+	ret = serial_write_blocking(serial, buffer, sizeof(buffer), 0);
+	if (ret < 0)
+		return ret;
+	if ((size_t)ret != sizeof(buffer))
+		return SR_ERR_IO;
+
+	return SR_OK;
 }
 
 static int send_long_command(const struct sr_dev_inst *sdi, uint32_t command)
 {
 	struct sr_serial_dev_inst *serial;
 	uint8_t buffer[4];
+	int ret;
 
 	buffer[0] = command >> 24;
 	buffer[1] = command >> 16;
@@ -49,7 +57,13 @@ static int send_long_command(const struct sr_dev_inst *sdi, uint32_t command)
 	if (!(serial = sdi->conn))
 		return SR_ERR;
 
-	return serial_write_blocking(serial, (const void *)buffer, 4, 0);
+	ret = serial_write_blocking(serial, buffer, sizeof(buffer), 0);
+	if (ret < 0)
+		return ret;
+	if ((size_t)ret != sizeof(buffer))
+		return SR_ERR_IO;
+
+	return SR_OK;
 }
 
 static void send_data(const struct sr_dev_inst *sdi, float sample)