fix(mcpwm): fix division by zero error in prescale

Kainarx · Kainarx · commit f194e0d58db4 · 2025-10-09T16:05:52.000+08:00
Closes espressif#17665
diff --git a/components/esp_driver_mcpwm/src/mcpwm_com.c b/components/esp_driver_mcpwm/src/mcpwm_com.c
@@ -246,12 +246,12 @@ esp_err_t mcpwm_set_prescale(mcpwm_group_t *group, uint32_t expect_module_resolu
         }
         module_prescale = fit_module_prescale;
         group_prescale = fit_group_prescale;
+        ESP_RETURN_ON_FALSE(group_prescale > 0 && group_prescale <= MCPWM_LL_MAX_GROUP_PRESCALE, ESP_ERR_INVALID_STATE, TAG,
+                            "set group prescale failed, group clock cannot match the resolution");
         group_resolution_hz = periph_src_clk_hz / group_prescale;
     }
 
     ESP_LOGD(TAG, "group (%d) calc prescale:%"PRIu32", module calc prescale:%"PRIu32"", group_id, group_prescale, module_prescale);
-    ESP_RETURN_ON_FALSE(group_prescale > 0 && group_prescale <= MCPWM_LL_MAX_GROUP_PRESCALE, ESP_ERR_INVALID_STATE, TAG,
-                        "set group prescale failed, group clock cannot match the resolution");
 
     // check if we need to update the group prescale, group prescale is shared by all mcpwm modules
     bool prescale_conflict = false;

Original file line number	Diff line number	Diff line change
`@@ -246,12 +246,12 @@ esp_err_t mcpwm_set_prescale(mcpwm_group_t *group, uint32_t expect_module_resolu`
`246`	`246`	`}`
`247`	`247`	`module_prescale = fit_module_prescale;`
`248`	`248`	`group_prescale = fit_group_prescale;`
	`249`	`+ ESP_RETURN_ON_FALSE(group_prescale > 0 && group_prescale <= MCPWM_LL_MAX_GROUP_PRESCALE, ESP_ERR_INVALID_STATE, TAG,`
	`250`	`+ "set group prescale failed, group clock cannot match the resolution");`
`249`	`251`	`group_resolution_hz = periph_src_clk_hz / group_prescale;`
`250`	`252`	`}`
`251`	`253`
`252`	`254`	`ESP_LOGD(TAG, "group (%d) calc prescale:%"PRIu32", module calc prescale:%"PRIu32"", group_id, group_prescale, module_prescale);`
`253`		`- ESP_RETURN_ON_FALSE(group_prescale > 0 && group_prescale <= MCPWM_LL_MAX_GROUP_PRESCALE, ESP_ERR_INVALID_STATE, TAG,`
`254`		`- "set group prescale failed, group clock cannot match the resolution");`
`255`	`255`
`256`	`256`	`// check if we need to update the group prescale, group prescale is shared by all mcpwm modules`
`257`	`257`	`bool prescale_conflict = false;`