Re: Serial 8250 DMA Broken on OMAP3630

[Andy Shevchenko]

On Sun, Oct 06, 2019 at 12:04:47PM -0500, Adam Ford wrote:

I think the best one who may shed a light is bigeasy@ (Cc'ed).

> Has anyone else had any issues using the CONFIG_SERIAL_8250_DMA on the OMAP?
> 
> I can use the DMA on the legacy, omap-serial driver, but when I enable
> the DMA on the 8250-omap driver, I get missing frames in Bluetooth.
> 
> The older driver seems to have an ISR that seems to address a variety
> of items compared to the very tiny ISR for 8250-omap.c.
> 
> I am not exactly sure where to start, but if someone has any
> suggestions on how I can troubleshoot, please let me know.  As of now,
> I have to disable CONFIG_SERIAL_8250_DMA to get the Bluetooth
> connected to UART2 operational on a DM3730 at 3,000,000 baud, but it
> appears to work just fine after some patches I just submitted for
> handling RTS/CTS.  The legacy omap-serial driver works fine with DMA.
> 
> adam

-- 
With Best Regards,
Andy Shevchenko