serial: lower severity of failed stream detect message

Reduce the message's log level from ERR to INFO when the serial stream
detect routine cannot find a valid packet. Although an error code gets
returned, the condition need not be fatal (can be the result of trying
several peers before success or finally giving up). Let callers decide
on the severity of failure to detect a specific device's presence, and
provide more context in their message which is more helpful to users.
Interested readers still get the message at slightly raised log levels.

This avoids confusing user perceivable situations like these:

  $ sigrok-cli --scan
  sr: serial: Didn't find a valid packet (read 0 bytes).
  sr: serial: Didn't find a valid packet (read 0 bytes).
  The following devices were found:
  demo - Demo device with 13 channels: D0 D1 D2 D3 D4 D5 D6 D7 A0 A1 A2 A3 A4

diff --git a/src/serial.c b/src/serial.c
index 34d7cbea3f9b40b965d588b8c4a6003a8d54cc24..1b76c935e3a0e1b73874b875185a18105f1f7f37 100644 (file)
--- a/src/serial.c
+++ b/src/serial.c
@@ -867,7 +867,7 @@ SR_PRIV int serial_stream_detect(struct sr_serial_dev_inst *serial,
 
        *buflen = ibuf;
 
-       sr_err("Didn't find a valid packet (read %zu bytes).", *buflen);
+       sr_info("Didn't find a valid packet (read %zu bytes).", *buflen);
 
        return SR_ERR;
 }