From: mika.westerberg@linux.intel.com (Mika Westerberg)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] spi/pxa2xx-pci: Enable DMA binding through device name
Date: Thu, 24 Jul 2014 17:06:20 +0300 [thread overview]
Message-ID: <20140724140620.GP1857@lahna.fi.intel.com> (raw)
In-Reply-To: <10365151.12bEvS9Gvj@wuerfel>
On Thu, Jul 24, 2014 at 01:42:10PM +0200, Arnd Bergmann wrote:
> 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.
It is also possible that the corresponding Baytrail system doesn't have
ACPI enabled BIOS in which case it dma_request_slave_channel() doesn't
help here.
> 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.
Good point. We will fix this, thanks.
next prev parent reply other threads:[~2014-07-24 14:06 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
2014-07-24 14:06 ` Mika Westerberg [this message]
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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