Ulrik Hald

iMX51 DMA support for uart in mainline

Discussion created by Ulrik Hald on Jun 27, 2012

I'm trying to find out if there DMA support for iMX51 UART in the mainline tree on pengutronix...


I see that there should be added support for UART DMA on imx6 via:

commit 07f060b3b4751b7847ed7c11730d87c994eec13a
Author: Huang Shijie <b32955@freescale.com>
Date:   Fri Nov 4 17:15:20 2011 +0800

    ENGR00163603-3 MX6Q/UART : add DMA support to uart driver
    add the DMA support for the uart driver.
    Signed-off-by: Huang Shijie <b32955@freescale.com>

...but this specifically mentions iMX6 and nothing else. Also, the upstream patch submission for this change (http://www.spinics.net/lists/linux-serial/msg06009.html) generated the following comment:



>Please test this patch at least on one more SoC. There should be nothing i.MX6 specific in here, the fact that the i.MX6 is mentioned several times in the comments make me suspicious.

There are bugs in the UART DMA code in the firmware before the imx6q. So we can not test the UART DMA except the imx6q arm2 board.

thanks  Huang Shijie

So, it doesn't sound like there is DMA support for any other than iMX6?

Is there any iMX51 BSP tree/branch where I can find working DMA support for UART?