machine,nrf528,i2c: fix multiple resume-stop on bus error

gen2thomas · gen2thomas · commit 5e6e91eadce6 · 2025-08-21T18:35:28.000+02:00
diff --git a/src/machine/machine_nrf528xx.go b/src/machine/machine_nrf528xx.go
@@ -78,14 +78,14 @@ func (i2c *I2C) Tx(addr uint16, w, r []byte) (err error) {
 		// Allow scheduler to run
 		gosched()
 
-		// Handle errors by ensuring STOP sent on bus
-		if i2c.Bus.EVENTS_ERROR.Get() != 0 {
+		// Handle first occurrence of error by ensuring STOP sent on bus
+		if err == nil && i2c.Bus.EVENTS_ERROR.Get() != 0 {
+			err = twiCError(i2c.Bus.ERRORSRC.Get())
 			if i2c.Bus.EVENTS_STOPPED.Get() == 0 {
 				// STOP cannot be sent during SUSPEND
 				i2c.Bus.TASKS_RESUME.Set(1)
 				i2c.Bus.TASKS_STOP.Set(1)
 			}
-			err = twiCError(i2c.Bus.ERRORSRC.Get())
 		}
 	}
 

Original file line number	Diff line number	Diff line change
`@@ -78,14 +78,14 @@ func (i2c *I2C) Tx(addr uint16, w, r []byte) (err error) {`
`78`	`78`	`// Allow scheduler to run`
`79`	`79`	`gosched()`
`80`	`80`
`81`		`- // Handle errors by ensuring STOP sent on bus`
`82`		`- if i2c.Bus.EVENTS_ERROR.Get() != 0 {`
	`81`	`+ // Handle first occurrence of error by ensuring STOP sent on bus`
	`82`	`+ if err == nil && i2c.Bus.EVENTS_ERROR.Get() != 0 {`
	`83`	`+ err = twiCError(i2c.Bus.ERRORSRC.Get())`
`83`	`84`	`if i2c.Bus.EVENTS_STOPPED.Get() == 0 {`
`84`	`85`	`// STOP cannot be sent during SUSPEND`
`85`	`86`	`i2c.Bus.TASKS_RESUME.Set(1)`
`86`	`87`	`i2c.Bus.TASKS_STOP.Set(1)`
`87`	`88`	`}`
`88`		`- err = twiCError(i2c.Bus.ERRORSRC.Get())`
`89`	`89`	`}`
`90`	`90`	`}`
`91`	`91`