The 64-bit values must not be demoted in size or the shift by max 48 will improperly clear the value entirely.

BsAtHome · BsAtHome · commit 01826c703863 · 2025-02-09T14:21:50.000+01:00
The abs() function must be promoted in size and use labs().
diff --git a/src/hal/drivers/mesa-hostmot2/sserial.c b/src/hal/drivers/mesa-hostmot2/sserial.c
@@ -1549,7 +1549,7 @@ int hm2_sserial_register_tram(hostmot2_t *hm2, hm2_sserial_remote_t *chan){
                                 case 64:
                                     shift = 0;
                                 }
-                            if (abs(((int)(p->s64_param) - (int)(p->s64_written)) >> shift) > 2) break;
+                            if (labs((p->s64_param - p->s64_written) >> shift) > 2) break;
                             *inst->state2 = 2; // increment indices
                             return *inst->state2;
                         default:

Original file line number	Diff line number	Diff line change
`@@ -1549,7 +1549,7 @@ int hm2_sserial_register_tram(hostmot2_t hm2, hm2_sserial_remote_t chan){`
`1549`	`1549`	`case 64:`
`1550`	`1550`	`shift = 0;`
`1551`	`1551`	`}`
`1552`		`- if (abs(((int)(p->s64_param) - (int)(p->s64_written)) >> shift) > 2) break;`
	`1552`	`+ if (labs((p->s64_param - p->s64_written) >> shift) > 2) break;`
`1553`	`1553`	`*inst->state2 = 2; // increment indices`
`1554`	`1554`	`return *inst->state2;`
`1555`	`1555`	`default:`