Re: [PATCH v2 2/2] spi: omap2-mcspi: Add FIFO buffer support

From: Illia Smyrnov
Date: Fri Jun 14 2013 - 12:16:41 EST

On 06/12/2013 06:47 PM, Mark Brown wrote:
On Tue, Jun 11, 2013 at 08:09:15PM +0300, Illia Smyrnov wrote:
The MCSPI controller has a built-in FIFO buffer to unload the DMA or interrupt
handler and improve data throughput. This patch adds FIFO buffer support for SPI
transfers in DMA mode.

The FIFO could be enabled for SPI module by setting up the "ti,spi-fifo-enabled"
configuration parameter in DT.
If FIFO enabled, the largest possible FIFO buffer size will be calculated and
setup for each SPI transfer. Even if the FIFO is enabled in DT, it won't be used
for the SPI transfers when: calculated FIFO buffer size is less then 2 bytes or
the FIFO buffer size isn't multiple of the SPI word length.

Why is the default to disable the FIFO?

I have changed this and sent v3 patches of the MCSPI FIFO support implementation. In this version driver set up the FIFO (if possible) for all the SPI transfers in DMA mode.
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at