From: arnd@arndb.de (Arnd Bergmann)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] spi/pxa2xx-pci: Enable DMA binding through device name
Date: Thu, 24 Jul 2014 13:42:10 +0200 [thread overview]
Message-ID: <10365151.12bEvS9Gvj@wuerfel> (raw)
In-Reply-To: <1406196111-22861-1-git-send-email-hock.leong.kweh@intel.com>
On Thursday 24 July 2014 18:01:51 Kweh Hock Leong wrote:
> From: "Chew, Chiau Ee" <chiau.ee.chew@intel.com>
>
> Intel LPSS Baytrail supports two DMA controllers and SPI is only
> using one of the DMA controller. During DMA channel request,
> we need to ensure the requested Tx and Rx channels are from the correct
> DMA controller. Thus, we add extra checking in filter callback funtion
> by matching against the DMA controller device name.
>
> Signed-off-by: Chew, Chiau Ee <chiau.ee.chew@intel.com>
> Signed-off-by: Kweh, Hock Leong <hock.leong.kweh@intel.com>
I'm confused. Doesn't Bay Trail use ACPI to do the DMA
engine configuration? That should set find the right device/chan_id/slave_id
combination without any interaction, through the use of dma_request_slave_channel.
On a related note, there seems to be a bug in this driver, which
attempts to set the slave_id through dmaengine_slave_config(), which
is wrong in both cases, ACPI and filter functions.
Arnd
next prev parent reply other threads:[~2014-07-24 11:42 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-24 10:01 [PATCH] spi/pxa2xx-pci: Enable DMA binding through device name Kweh Hock Leong
2014-07-24 11:18 ` Andy Shevchenko
2014-07-24 11:42 ` Arnd Bergmann [this message]
2014-07-24 14:06 ` Mika Westerberg
2014-07-25 7:11 ` Mika Westerberg
2014-07-25 7:58 ` Arnd Bergmann
2014-07-25 8:22 ` Mika Westerberg
2014-07-25 8:38 ` Arnd Bergmann
2014-07-25 9:07 ` Mika Westerberg
2014-07-25 9:55 ` Mika Westerberg
2014-07-25 10:19 ` Arnd Bergmann
2014-07-25 10:45 ` Andy Shevchenko
2014-07-25 15:55 ` Arnd Bergmann
2014-07-25 21:45 ` One Thousand Gnomes
2014-07-28 11:06 ` Andy Shevchenko
2014-07-28 11:56 ` Shevchenko, Andriy
2014-07-28 12:47 ` Arnd Bergmann
2014-07-28 13:34 ` Andy Shevchenko
2014-07-28 14:02 ` Arnd Bergmann
2014-07-28 9:28 ` Mika Westerberg
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