extmod/machine_i2c: Do a fast poll during I2C.scan().

dpgeorge · dpgeorge · commit dff293840e38 · 2023-11-08T23:34:08.000+11:00
Fixes issue #12912. Signed-off-by: Damien George <damien@micropython.org>
diff --git a/extmod/machine_i2c.c b/extmod/machine_i2c.c
@@ -328,7 +328,12 @@ STATIC mp_obj_t machine_i2c_scan(mp_obj_t self_in) {
         if (ret == 0) {
             mp_obj_list_append(list, MP_OBJ_NEW_SMALL_INT(addr));
         }
-        #ifdef MICROPY_EVENT_POLL_HOOK
+        // This scan loop may run for some time, so process any pending events/exceptions,
+        // or allow the port to run any necessary background tasks.  But do it as fast as
+        // possible, in particular we are not waiting on any events.
+        #if defined(MICROPY_EVENT_POLL_HOOK_FAST)
+        MICROPY_EVENT_POLL_HOOK_FAST;
+        #elif defined(MICROPY_EVENT_POLL_HOOK)
         MICROPY_EVENT_POLL_HOOK
         #endif
     }

Original file line number	Diff line number	Diff line change
`@@ -328,7 +328,12 @@ STATIC mp_obj_t machine_i2c_scan(mp_obj_t self_in) {`
`328`	`328`	`if (ret == 0) {`
`329`	`329`	`mp_obj_list_append(list, MP_OBJ_NEW_SMALL_INT(addr));`
`330`	`330`	`}`
`331`		`- #ifdef MICROPY_EVENT_POLL_HOOK`
	`331`	`+ // This scan loop may run for some time, so process any pending events/exceptions,`
	`332`	`+ // or allow the port to run any necessary background tasks. But do it as fast as`
	`333`	`+ // possible, in particular we are not waiting on any events.`
	`334`	`+ #if defined(MICROPY_EVENT_POLL_HOOK_FAST)`
	`335`	`+ MICROPY_EVENT_POLL_HOOK_FAST;`
	`336`	`+ #elif defined(MICROPY_EVENT_POLL_HOOK)`
`332`	`337`	`MICROPY_EVENT_POLL_HOOK`
`333`	`338`	`#endif`
`334`	`339`	`}`