From: viresh.kumar@st.com (Viresh Kumar)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/8] dmaengine: Add flow controller information to dma_slave_config
Date: Wed, 18 Jan 2012 16:10:51 +0530 [thread overview]
Message-ID: <4F16A1B3.5000409@st.com> (raw)
In-Reply-To: <CACRpkdbwZ5h15b0gBJP6xdk5TJt+CSeNRbEB8o2vzp9FbyD9AA@mail.gmail.com>
On 1/18/2012 4:06 PM, Linus Walleij wrote:
> On Tue, Jan 17, 2012 at 10:07 AM, Viresh Kumar <viresh.kumar@st.com> wrote:
>> On 1/17/2012 2:07 PM, Linus Walleij wrote:
> Maybe I should say that it's supposed to transfer information from
> the driver to the DMA engine that:
>
> 1) The driver naturally "knows", like which physical register address
> the FIFO is in or burst width etc and the DMA engine has no
> business knowing.
>
> 2) That needs to change at runtime, like for example how the PL022
> driver request 32, 16 or 8 bit wide transfers depending on bus
> width.
>
> I think master mode could very well be under (1). So the driver knows
> if this hardware expects the DMA engine to drive the transaction or
> if it's the device itself that should drive it.
>
> So I'm starting to think like you :-)
:)
>> One more thing. I missed few things in this patch:
>> - Need to update all instances of struct dma_slave_config with
>> .device_fc = false
>
> All statically defined structs contain zero == false by default
> so it's not needed.
>
> Make sure any dynamic allocations (I don't know of any!)
> are kzalloc() though.
>
I already fixed these in V2.
Most of the drivers created inside routines. They are not getting
initialized to _zero_ , so i had to fix it.
There are few though, who used kzalloc. I didn't touch them.
--
viresh
WARNING: multiple messages have this Message-ID (diff)
From: Viresh Kumar <viresh.kumar@st.com>
To: Linus Walleij <linus.walleij@linaro.org>
Cc: "vinod.koul@intel.com" <vinod.koul@intel.com>,
"dan.j.williams@intel.com" <dan.j.williams@intel.com>,
"linux@arm.linux.org.uk" <linux@arm.linux.org.uk>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
Armando VISCONTI <armando.visconti@st.com>,
Shiraz HASHIM <shiraz.hashim@st.com>,
Vipin KUMAR <vipin.kumar@st.com>,
Rajeev KUMAR <rajeev-dlh.kumar@st.com>,
Deepak SIKRI <deepak.sikri@st.com>,
Vipul Kumar SAMAR <vipulkumar.samar@st.com>,
Amit VIRDI <Amit.VIRDI@st.com>,
Pratyush ANAND <pratyush.anand@st.com>,
Bhupesh SHARMA <bhupesh.sharma@st.com>,
"viresh.linux@gmail.com" <viresh.linux@gmail.com>,
Bhavna YADAV <bhavna.yadav@st.com>,
Vincenzo FRASCINO <Vincenzo.FRASCINO@st.com>,
Mirko GARDI <mirko.gardi@st.com>
Subject: Re: [PATCH 2/8] dmaengine: Add flow controller information to dma_slave_config
Date: Wed, 18 Jan 2012 16:10:51 +0530 [thread overview]
Message-ID: <4F16A1B3.5000409@st.com> (raw)
In-Reply-To: <CACRpkdbwZ5h15b0gBJP6xdk5TJt+CSeNRbEB8o2vzp9FbyD9AA@mail.gmail.com>
On 1/18/2012 4:06 PM, Linus Walleij wrote:
> On Tue, Jan 17, 2012 at 10:07 AM, Viresh Kumar <viresh.kumar@st.com> wrote:
>> On 1/17/2012 2:07 PM, Linus Walleij wrote:
> Maybe I should say that it's supposed to transfer information from
> the driver to the DMA engine that:
>
> 1) The driver naturally "knows", like which physical register address
> the FIFO is in or burst width etc and the DMA engine has no
> business knowing.
>
> 2) That needs to change at runtime, like for example how the PL022
> driver request 32, 16 or 8 bit wide transfers depending on bus
> width.
>
> I think master mode could very well be under (1). So the driver knows
> if this hardware expects the DMA engine to drive the transaction or
> if it's the device itself that should drive it.
>
> So I'm starting to think like you :-)
:)
>> One more thing. I missed few things in this patch:
>> - Need to update all instances of struct dma_slave_config with
>> .device_fc = false
>
> All statically defined structs contain zero == false by default
> so it's not needed.
>
> Make sure any dynamic allocations (I don't know of any!)
> are kzalloc() though.
>
I already fixed these in V2.
Most of the drivers created inside routines. They are not getting
initialized to _zero_ , so i had to fix it.
There are few though, who used kzalloc. I didn't touch them.
--
viresh
next prev parent reply other threads:[~2012-01-18 10:40 UTC|newest]
Thread overview: 56+ 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 ` 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 ` Viresh Kumar
2012-01-16 9:50 ` [PATCH 2/8] dmaengine: Add flow controller information to dma_slave_config Viresh Kumar
2012-01-16 9:50 ` Viresh Kumar
2012-01-17 8:37 ` Linus Walleij
2012-01-17 8:37 ` Linus Walleij
2012-01-17 9:07 ` Viresh Kumar
2012-01-17 9:07 ` Viresh Kumar
2012-01-18 10:36 ` Linus Walleij
2012-01-18 10:36 ` Linus Walleij
2012-01-18 10:40 ` Viresh Kumar [this message]
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 ` 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 ` 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 9:50 ` Viresh Kumar
2012-01-16 10:47 ` Sergei Shtylyov
2012-01-16 10:47 ` Sergei Shtylyov
2012-01-16 10:52 ` Viresh Kumar
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 ` 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 9:50 ` Viresh Kumar
2012-01-16 10:54 ` Russell King - ARM Linux
2012-01-16 10:54 ` Russell King - ARM Linux
2012-01-16 11:44 ` Viresh Kumar
2012-01-16 11:44 ` Viresh Kumar
2012-01-17 8:52 ` Linus Walleij
2012-01-17 8:52 ` Linus Walleij
2012-01-17 9:07 ` Viresh Kumar
2012-01-17 9:07 ` Viresh Kumar
2012-01-18 9:35 ` Russell King - ARM Linux
2012-01-18 9:35 ` Russell King - ARM Linux
2012-01-19 17:34 ` Linus Walleij
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 9:50 ` Viresh Kumar
2012-01-16 11:42 ` Viresh Kumar
2012-01-16 11:42 ` Viresh Kumar
2012-01-17 8:49 ` Linus Walleij
2012-01-17 8:49 ` Linus Walleij
2012-01-17 9:15 ` Viresh Kumar
2012-01-17 9:15 ` Viresh Kumar
2012-01-17 9:19 ` Viresh Kumar
2012-01-17 9:19 ` Viresh Kumar
2012-01-17 10:19 ` Viresh Kumar
2012-01-17 10:19 ` Viresh Kumar
2012-01-17 10:10 ` Jassi Brar
2012-01-17 10:10 ` Jassi Brar
2012-01-17 10:19 ` Viresh Kumar
2012-01-17 10:19 ` Viresh Kumar
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