From: viresh.kumar@st•com (Viresh Kumar)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 7/8] dmaengine/dw_dmac: Unmap all memory buffers after completion of slave transfers
Date: Tue, 17 Jan 2012 14:37:10 +0530 [thread overview]
Message-ID: <4F153A3E.8010409@st.com> (raw)
In-Reply-To: <CACRpkdY-4wWeD=3mJiChi6+4=iBMcd3kVh3h4JmDZ5ySXY3KCA@mail.gmail.com>
On 1/17/2012 2:22 PM, Linus Walleij wrote:
> Basically the driver using the dmaengine shall map/unmap buffers
> used for slave transfers, not the driver.
>
> I usually map them before setting up a transfer and unmaps them
> when egtting the callback from the DMA engine that the transfer is
> complete.
>
You implemented similar stuff in amba-pl08x :) .
if (!plchan->slave)
pl08x_unmap_buffers(txd);
> Why do you want to do this?
This is because people can pass in flags which are
DMA_COMPL_SKIP_SRC_UNMAP, etc.
If they are not passed, then DMA driver must do it for them.
Sorry if i am understanding the DMA logic incorrectly.
--
viresh
next prev parent reply other threads:[~2012-01-17 9:07 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-16 9:50 [PATCH 0/9] dmaengine: Pl08x and dw_dmac updates Viresh Kumar
2012-01-16 9:50 ` [PATCH 1/8] dmaengine/dw_dmac: Hibernation support in dw_dmac Viresh Kumar
2012-01-16 9:50 ` [PATCH 2/8] dmaengine: Add flow controller information to dma_slave_config Viresh Kumar
2012-01-17 8:37 ` Linus Walleij
2012-01-17 9:07 ` Viresh Kumar
2012-01-18 10:36 ` Linus Walleij
2012-01-18 10:40 ` Viresh Kumar
2012-01-16 9:50 ` [PATCH 3/8] dmaengine/amba-pl08x: Take flow controller info from DMA_SLAVE_CONFIG Viresh Kumar
2012-01-16 9:50 ` [PATCH 4/8] dmaengine/dw_dmac: Don't use magic number for total number of channels Viresh Kumar
2012-01-16 9:50 ` [PATCH 5/8] dmaengine/dw_dmac: Use platform_get_drvdata instead of accessing dev directly Viresh Kumar
2012-01-16 10:47 ` Sergei Shtylyov
2012-01-16 10:52 ` Viresh Kumar
2012-01-16 9:50 ` [PATCH 6/8] dmaengine/dw_dmac: Don't handle block interrupts Viresh Kumar
2012-01-16 9:50 ` [PATCH 7/8] dmaengine/dw_dmac: Unmap all memory buffers after completion of slave transfers Viresh Kumar
2012-01-16 10:54 ` Russell King - ARM Linux
2012-01-16 11:44 ` Viresh Kumar
2012-01-17 8:52 ` Linus Walleij
2012-01-17 9:07 ` Viresh Kumar [this message]
2012-01-18 9:35 ` Russell King - ARM Linux
2012-01-19 17:34 ` Linus Walleij
2012-01-16 9:50 ` [PATCH 8/8] dmaengine/dw_dmac: Add support for DMA_SLAVE_CONFIG Viresh Kumar
2012-01-16 11:42 ` Viresh Kumar
2012-01-17 8:49 ` Linus Walleij
2012-01-17 9:15 ` Viresh Kumar
2012-01-17 9:19 ` Viresh Kumar
2012-01-17 10:19 ` Viresh Kumar
2012-01-17 10:10 ` Jassi Brar
2012-01-17 10:19 ` Viresh Kumar
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