serial: 8250_dma: don't bother DMA with small transfers
authorAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Thu, 22 Jan 2015 12:40:27 +0000 (14:40 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 2 Feb 2015 18:11:26 +0000 (10:11 -0800)
commit9119fba0cfeda6d415c9f068df66838a104b87cb
tree53dd37bcf84ef8d0bd4e461b177b34c601d03844
parenta39d1da11b675b2cc2e0ffaafa8952ac7c3bd104
serial: 8250_dma: don't bother DMA with small transfers

If we would like to send amount of data less than FIFO size we better would do
this via PIO mode. Otherwise the overhead could be significant.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/tty/serial/8250/8250_dma.c