From: martinwguy@gmail.com (Martin Guy)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v4 1/2] spi: implemented driver for Cirrus EP93xx SPI controller
Date: Thu, 22 Apr 2010 15:28:27 +0100 [thread overview]
Message-ID: <x2g56d259a01004220728i7f07d492t4c4f63e0ef2e38d9@mail.gmail.com> (raw)
In-Reply-To: <0D753D10438DA54287A00B0270842697636D8C8CDD@AUSP01VMBX24.collaborationhost.net>
On 4/22/10, H Hartley Sweeten <hartleys@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
next prev parent reply other threads:[~2010-04-22 14:28 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-20 15:11 [PATCH v4 0/2] spi: driver for Cirrus EP93xx SPI controller Mika Westerberg
2010-04-20 15:11 ` [PATCH v4 1/2] spi: implemented " Mika Westerberg
2010-04-20 17:24 ` H Hartley Sweeten
2010-04-21 7:16 ` Mika Westerberg
2010-04-21 16:47 ` H Hartley Sweeten
2010-04-21 16:54 ` Mika Westerberg
2010-04-22 2:47 ` H Hartley Sweeten
2010-04-22 5:53 ` Mika Westerberg
2010-04-22 14:11 ` Martin Guy
2010-04-22 14:28 ` Martin Guy [this message]
2010-04-22 17:39 ` H Hartley Sweeten
2010-04-22 20:19 ` Martin Guy
2010-04-20 22:16 ` H Hartley Sweeten
2010-04-20 23:54 ` Martin Guy
2010-04-21 0:11 ` H Hartley Sweeten
2010-04-21 0:43 ` [spi-devel-general] " H Hartley Sweeten
2010-04-21 1:10 ` Martin Guy
2010-04-21 1:52 ` H Hartley Sweeten
2010-04-21 7:00 ` Mika Westerberg
2010-04-21 10:46 ` Mika Westerberg
2010-04-21 18:00 ` H Hartley Sweeten
2010-04-22 5:45 ` Mika Westerberg
2010-04-22 21:29 ` Ryan Mallon
2010-04-22 17:55 ` Mika Westerberg
2010-04-22 20:43 ` H Hartley Sweeten
2010-04-23 5:20 ` Mika Westerberg
2010-04-23 17:24 ` H Hartley Sweeten
2010-04-23 23:01 ` [spi-devel-general] " H Hartley Sweeten
2010-04-25 9:29 ` Martin Guy
2010-04-25 9:38 ` Martin Guy
2010-04-25 20:25 ` H Hartley Sweeten
2010-04-26 10:02 ` Mika Westerberg
2010-04-26 16:54 ` H Hartley Sweeten
2010-04-26 10:09 ` Mika Westerberg
2010-04-26 14:35 ` Martin Guy
2010-04-26 17:05 ` H Hartley Sweeten
2010-04-29 18:30 ` Mika Westerberg
2010-04-21 6:37 ` Mika Westerberg
2010-04-21 17:08 ` H Hartley Sweeten
2010-04-24 18:14 ` Martin Guy
2010-04-25 19:55 ` H Hartley Sweeten
2010-04-26 10:34 ` Mika Westerberg
2010-04-26 12:58 ` Martin Guy
2010-04-20 15:11 ` [PATCH v4 2/2] ep93xx: SPI driver platform support code Mika Westerberg
2010-04-20 16:35 ` H Hartley Sweeten
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