View Issue Details

IDProjectCategoryView StatusLast Update
0004206fsimx_LinuxKernelpublic2020-05-05 14:48
Reportergerbach Assigned To 
PrioritynormalSeverityfeatureReproducibilityalways
Status resolvedResolutionfixed 
Product Versionfsimx6sx-B2019.11 
Target Versionfsimx6-Y2020.03Fixed in Versionfsimx6-Y2020.03 
Summary0004206: [i.MX6-ALL] Add possibility to disable Direct Memory Access for imx-UARTvia device tree
DescriptionThe imx uart driver automatically enables dma for all non-console uarts.
This adds an 4kB buffer, which delays the transmission of the received data to the userspace.
Also, parity detection is not implemented for dma-uart.

Some customers need immediate data transmission and parity checking so we want to add a possibility to disable dma for uart devices via the device tree
Forum Linkhttps://forum.fs-net.de/index.php?thread/4471-uart-parity-check-not-working/&postID=15064#post15064

Activities

gerbach

2020-02-13 15:25

developer   ~0003058

Git commit: 92f7013f9f2f6ddc9748a97e72c784869405dd7d

Improve imx-uart driver
   
    The imx uart driver automatically enables dma for all non-console uarts.
    This adds an 4kB buffer, which delays the transmission of the received
    data to the userspace.
    Also, parity detection is not implemented for dma-uart.
    
    By adding "no-dma" to a uart entry in the devicetree, the uart will now
    be interrupt-driven, will not buffer the data and will support parity
    detection