Linux/AM3358: UART HW flow control with DMA enabled

Sung-IL

Part Number: AM3358

Tool/software: Linux

Dear Champs,

Could you please let me know if HW flow control can be used in current 8250 UART driver with DMA enabled in current Linux PSDK 4.0?

My customer is trying to use 8250 UART driver, but found there was an issue in using HW flow control with DMA enabled.

So, they want to know if it was resolved or not.

And, actually they are using Linux PSDK 2.0.2.11 now. Could you please check the patch also?

Thanks and Best Regards,

SI.

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

The software team have been notified. They will respond here.

0 Cvetolin Shulev-XID over 8 years ago

TI__Guru 65405 points

Hi SI,

The CONFIG_SERIAL_8250_DMA Linux kernel config option is enabled by default in Linux PSDK v04.00.00.04.
Yes, you can use HW flow control with and DMA enable with current 8250 UART driver.

BR
Tsvetolin Shulev

0 Sung-IL over 8 years ago in reply to Cvetolin Shulev-XID

TI__Mastermind 31150 points

Hi,

How about Linux PSDK 2.0.2.11? Actually the PSDK version used by customer is Linux PSDK 2.0.2.11, and they failed to enabled DMA with HW flow control.

When I checked kernel release note for PSDK v2.0.2.11, there was no known error for this issue although it was listed in PSDKv2.0.1.7.

So, I requested to test it again in their PSDK v2.0.2.11, but they failed to enable DMA with HW flow control.

Could you please check below their configuration?

- .config file