[PATCH v4 1/2] spi: implemented driver for Cirrus EP93xx SPI controller
Martin Guy
martinwguy at gmail.com
Thu Apr 22 10:28:27 EDT 2010
On 4/22/10, H Hartley Sweeten <hartleys at visionengravers.com> wrote:
> First, every spi transaction, including a single byte transfer, is
> going to generate at least two interrupts. One when the interrupts
> are first enabled because the TX FIFO is empty. And a second when
> that byte has been transferred and the TX FIFO is again empty.
>
> The first interrupt can be prevented by priming the TX FIFO before
> enabling the interrupts. All you need to do is call ep93xx_spi_read_write
> right before ep93xx_spi_enable_interrupts.
Nice. That increases the data throughput from 367 to 372 kB/sec and
reduces the CPU usage from 61 to 60.2% for large transfers
M
More information about the linux-arm-kernel
mailing list