WebThe callback doesn't care, but the DMA controller cares about this flag. I see a possible race condition here. If i set the DONE flag for a specific buffer descriptor before handling the data belonging to this buffer descriptor (aka running the callback function) the DMA script running at the same time could corrupt that data while being processed. WebThis patch series was tested with the current kernel and backported to kernel 4.15 with a special use case using a WL1837MOD via UART and provoking the hanging of UART RX DMA within seconds after starting a test application. It resulted in well known "Bluetooth: hci0: command 0x0408 tx timeout" errors and complete stop of UART data reception.
Solved: how to enhance uart baud rate for imx6 - NXP Community
WebWe need to know at probe time if we can enable DMA. (RS-485 could be enabled after that). Let's therefore only enable DMA if it is not an i.MX6Q/D UART with uart-has-rtscts in the DT and CONFIG_SMP enabled. WebYou don't need circular buffers for UART data but they make the most efficient use of your buffer memory and let you have the longest messages lengths compared to ping-ping buffers or simple linear buffers: electronics.stackexchange.com/questions/498526/… Share Cite Follow answered May 12, 2024 at 21:59 DKNguyen 53.3k 3 65 148 Add a comment description of god in revelations
Problem of transmitting ADC values using DMA to UART
WebThe IMX UART has a 32 bytes HW buffer which can be filled up in 2777us at 115200 baud or 80us at 4Mbaud (supported by IMX53). Taking this in consideration there is a good probability to lose data because of the DMA startup latency. Our tests (explained below) indicates a latency up to 4400us when creating interrupt load and ~70us without. WebMay 26, 2016 · Each unit has two variables: an array called buffer [] and a counter called bufferCount. The buffer holds the UART data as it streams in and the bufferCount holds how much data has been sent. This counter can be used in two ways: Find how much data is present on the buffer Decide where to push / pop data to / from the buffer description of gneiss metamorphic rock