svn commit: r354068 - head/sys/dev/ow

[Andriy Gapon]

Author: avg
Date: Fri Oct 25 13:47:17 2019
New Revision: 354068
URL: https://svnweb.freebsd.org/changeset/base/354068

Log:
  ow_temp: better scopes for the lock
  
  The lock is used only for start / stop signaling.
  It is used only for 'flags' field and the related condition variable.
  
  This change is a follow-up to r354067, it was suggested by Warner in
  D22107.
  
  Suggested by:	imp
  MFC after:	1 week

Modified:
  head/sys/dev/ow/ow_temp.c

Modified: head/sys/dev/ow/ow_temp.c
==============================================================================
--- head/sys/dev/ow/ow_temp.c	Fri Oct 25 13:42:36 2019	(r354067)
+++ head/sys/dev/ow/ow_temp.c	Fri Oct 25 13:47:17 2019	(r354068)
@@ -145,9 +145,9 @@ ow_temp_event_thread(void *arg)
 	sc->flags |= OW_TEMP_RUNNING;
 	mtx_unlock(&sc->temp_lock);
 	ow_temp_read_power_supply(sc->dev, &sc->parasite);
-	mtx_lock(&sc->temp_lock);
 	if (sc->parasite)
 		device_printf(sc->dev, "Running in parasitic mode unsupported\n");
+	mtx_lock(&sc->temp_lock);
 	while ((sc->flags & OW_TEMP_DONE) == 0) {
 		mtx_unlock(&sc->temp_lock);
 		ow_temp_convert_t(sc->dev);
@@ -155,10 +155,9 @@ ow_temp_event_thread(void *arg)
 		msleep(sc, &sc->temp_lock, 0, "owtcvt", hz);
 		if (sc->flags & OW_TEMP_DONE)
 			break;
+		mtx_unlock(&sc->temp_lock);
 		for (retries = 5; retries > 0; retries--) {
-			mtx_unlock(&sc->temp_lock);
 			rv = ow_temp_read_scratchpad(sc->dev, scratch, sizeof(scratch));
-			mtx_lock(&sc->temp_lock);
 			if (rv == 0) {
 				crc = own_crc(sc->dev, scratch, sizeof(scratch) - 1);
 				if (crc == scratch[8]) {
@@ -182,6 +181,7 @@ ow_temp_event_thread(void *arg)
 			} else
 				sc->bad_reads++;
 		}
+		mtx_lock(&sc->temp_lock);
 		msleep(sc, &sc->temp_lock, 0, "owtcvt", sc->reading_interval);
 	}
 	sc->flags &= ~OW_TEMP_RUNNING;