uart_set_baudrate sets incorrect baud rate

[user91829]

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1.     static QueueHandle_t uart0_queue;
2.    uart_config_t uart_config = {
3.         .baud_rate = 115200,
4.         .data_bits = UART_DATA_8_BITS,
5.         .parity = UART_PARITY_DISABLE,
6.         .stop_bits = UART_STOP_BITS_1,
7.         .flow_ctrl = UART_HW_FLOWCTRL_DISABLE
8.     };
9.     // Install UART driver, and get the queue.
10.     uart_driver_install(UART_NUM_1, 1024, 1024, 20, &uart0_queue, 0);
11.     uart_param_config(UART_NUM_1, &uart_config);
12.     vTaskDelay(100 / portTICK_RATE_MS);
13.     uint32_t baudrate;
14.     ESP_LOGI("MAIN", "BAUD RATE 0: %d", baudrate);
15.     uart_get_baudrate(UART_NUM_1, &baudrate);
16.     ESP_LOGI("MAIN", "BAUD RATE 1: %d", baudrate);
17.     vTaskDelay(100 / portTICK_RATE_MS);
18.     uart_set_baudrate(UART_NUM_1, 230400);
19.     vTaskDelay(100 / portTICK_RATE_MS);
20.     uart_get_baudrate(UART_NUM_1, &baudrate);
21.     ESP_LOGI("MAIN", "BAUD RATE 2: %d", baudrate);
22.     vTaskDelay(100 / portTICK_RATE_MS);
23.     uart_set_baudrate(UART_NUM_1, 460800);
24.     vTaskDelay(100 / portTICK_RATE_MS);
25.     uart_get_baudrate(UART_NUM_1, &baudrate);
26.     ESP_LOGI("MAIN", "BAUD RATE 3: %d", baudrate);
27.     vTaskDelay(100 / portTICK_RATE_MS);
28.     uart_set_baudrate(UART_NUM_1, 921600);
29.     vTaskDelay(100 / portTICK_RATE_MS);
30.     uart_get_baudrate(UART_NUM_1, &baudrate);
31.     ESP_LOGI("MAIN", "BAUD RATE 4: %d", baudrate);

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The above code gives the following output

I (857) MAIN: BAUD RATE 0: 0
I (857) MAIN: BAUD RATE 1: 115201
I (1057) MAIN: BAUD RATE 2: 230423
I (1257) MAIN: BAUD RATE 3: 460929
I (1457) MAIN: BAUD RATE 4: 922190

Am I doing something wrong here ?

I am using latest docker image `espressif/idf:release-v4.4` and this is the only code in `app_main()`

[WiFive]

approximation is to be expected due to divider and clock frequency limitations