From: Baolin Wang <baolin.wang@linaro.org>
To: Vinod Koul <vkoul@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>,
eric.long@unisoc.com, Orson Zhai <orsonzhai@gmail.com>,
Chunyan Zhang <zhang.lyra@gmail.com>,
Mark Brown <broonie@kernel.org>,
dmaengine@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 4/7] dmaengine: sprd: Add device validation to support multiple controllers
Date: Tue, 30 Apr 2019 16:53:32 +0800 [thread overview]
Message-ID: <CAMz4kuLFyckFdzVgL9FH0xW8036OoAbyjHqfOAVhibPyNssPDA@mail.gmail.com> (raw)
Message-ID: <20190430085332.d9yd_jYT9XLQ4_8zj8omYR4z6LYP1n_J9V3nUuNVFfM@z> (raw)
In-Reply-To: <CAMz4kuKV3J+aw9sic=QOhmcnr+H_pZ-pmq4pRbLX1R+XAR=phA@mail.gmail.com>
Hi Vinod,
On Tue, 30 Apr 2019 at 16:34, Baolin Wang <baolin.wang@linaro.org> wrote:
>
> On Tue, 30 Apr 2019 at 16:30, Vinod Koul <vkoul@kernel.org> wrote:
> >
> > On 30-04-19, 13:30, Baolin Wang wrote:
> > > On Mon, 29 Apr 2019 at 22:05, Vinod Koul <vkoul@kernel.org> wrote:
> > > >
> > > > On 29-04-19, 20:20, Baolin Wang wrote:
> > > > > On Mon, 29 Apr 2019 at 19:57, Vinod Koul <vkoul@kernel.org> wrote:
> > > > > >
> > > > > > On 15-04-19, 20:14, Baolin Wang wrote:
> > > > > > > From: Eric Long <eric.long@unisoc.com>
> > > > > > >
> > > > > > > Since we can support multiple DMA engine controllers, we should add
> > > > > > > device validation in filter function to check if the correct controller
> > > > > > > to be requested.
> > > > > > >
> > > > > > > Signed-off-by: Eric Long <eric.long@unisoc.com>
> > > > > > > Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
> > > > > > > ---
> > > > > > > drivers/dma/sprd-dma.c | 5 +++++
> > > > > > > 1 file changed, 5 insertions(+)
> > > > > > >
> > > > > > > diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
> > > > > > > index 0f92e60..9f99d4b 100644
> > > > > > > --- a/drivers/dma/sprd-dma.c
> > > > > > > +++ b/drivers/dma/sprd-dma.c
> > > > > > > @@ -1020,8 +1020,13 @@ static void sprd_dma_free_desc(struct virt_dma_desc *vd)
> > > > > > > static bool sprd_dma_filter_fn(struct dma_chan *chan, void *param)
> > > > > > > {
> > > > > > > struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
> > > > > > > + struct of_phandle_args *dma_spec =
> > > > > > > + container_of(param, struct of_phandle_args, args[0]);
> > > > > > > u32 slave_id = *(u32 *)param;
> > > > > > >
> > > > > > > + if (chan->device->dev->of_node != dma_spec->np)
> > > > > >
> > > > > > Are you not using of_dma_find_controller() that does this, so this would
> > > > > > be useless!
> > > > >
> > > > > Yes, we can use of_dma_find_controller(), but that will be a little
> > > > > complicated than current solution. Since we need introduce one
> > > > > structure to save the node to validate in the filter function like
> > > > > below, which seems make things complicated. But if you still like to
> > > > > use of_dma_find_controller(), I can change to use it in next version.
> > > >
> > > > Sorry I should have clarified more..
> > > >
> > > > of_dma_find_controller() is called by xlate, so you already run this
> > > > check, so why use this :)
> > >
> > > The of_dma_find_controller() can save the requested device node into
> > > dma_spec, and in the of_dma_simple_xlate() function, it will call
> > > dma_request_channel() to request one channel, but it did not validate
> > > the device node to find the corresponding dma device in
> > > dma_request_channel(). So we should in our filter function to validate
> > > the device node with the device node specified by the dma_spec. Hope I
> > > make things clear.
> >
> > But dma_request_channel() calls of_dma_request_slave_channel() which
> > invokes of_dma_find_controller() why is it broken for you if that is the
> > case..
>
> No,the calling process should be:
> dma_request_slave_channel()
> --->dma_request_chan()--->of_dma_request_slave_channel()---->of_dma_simple_xlate()
> ----> dma_request_channel().
>
You can check other drivers, they also will save the device node to
validate in their filter function.
For example the imx-sdma driver:
https://elixir.bootlin.com/linux/v5.1-rc6/source/drivers/dma/imx-sdma.c#L1931
--
Baolin Wang
Best Regards
next prev parent reply other threads:[~2019-04-30 8:53 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-15 12:14 [PATCH 0/7] Fix some bugs and add new feature for Spreadtrum DMA engine Baolin Wang
2019-04-15 12:14 ` [1/7] dmaengine: sprd: Fix the possible crash when getting engine status Baolin Wang
2019-04-15 12:14 ` [PATCH 1/7] " Baolin Wang
2019-04-29 11:35 ` [1/7] " Vinod Koul
2019-04-29 11:35 ` [PATCH 1/7] " Vinod Koul
2019-04-29 11:49 ` [1/7] " Baolin Wang
2019-04-29 11:49 ` [PATCH 1/7] " Baolin Wang
2019-04-29 12:02 ` [1/7] " Vinod Koul
2019-04-29 12:02 ` [PATCH 1/7] " Vinod Koul
2019-04-15 12:14 ` [2/7] dmaengine: sprd: Add validation of current descriptor in irq handler Baolin Wang
2019-04-15 12:14 ` [PATCH 2/7] " Baolin Wang
2019-04-15 12:14 ` [3/7] dmaengine: sprd: Fix the incorrect start for 2-stage destination channels Baolin Wang
2019-04-15 12:14 ` [PATCH 3/7] " Baolin Wang
2019-04-15 12:14 ` [4/7] dmaengine: sprd: Add device validation to support multiple controllers Baolin Wang
2019-04-15 12:14 ` [PATCH 4/7] " Baolin Wang
2019-04-29 11:57 ` [4/7] " Vinod Koul
2019-04-29 11:57 ` [PATCH 4/7] " Vinod Koul
2019-04-29 12:20 ` [4/7] " Baolin Wang
2019-04-29 12:20 ` [PATCH 4/7] " Baolin Wang
2019-04-29 14:05 ` [4/7] " Vinod Koul
2019-04-29 14:05 ` [PATCH 4/7] " Vinod Koul
2019-04-30 5:30 ` [4/7] " Baolin Wang
2019-04-30 5:30 ` [PATCH 4/7] " Baolin Wang
2019-04-30 8:29 ` [4/7] " Vinod Koul
2019-04-30 8:29 ` [PATCH 4/7] " Vinod Koul
2019-04-30 8:34 ` [4/7] " Baolin Wang
2019-04-30 8:34 ` [PATCH 4/7] " Baolin Wang
2019-04-30 8:53 ` Baolin Wang [this message]
2019-04-30 8:53 ` Baolin Wang
2019-05-02 6:01 ` [4/7] " Vinod Koul
2019-05-02 6:01 ` [PATCH 4/7] " Vinod Koul
2019-05-06 4:48 ` Baolin Wang
2019-04-15 12:14 ` [5/7] dmaengine: sprd: Fix block length overflow Baolin Wang
2019-04-15 12:14 ` [PATCH 5/7] " Baolin Wang
2019-04-15 12:15 ` [6/7] dmaengine: sprd: Fix the right place to configure 2-stage transfer Baolin Wang
2019-04-15 12:15 ` [PATCH 6/7] " Baolin Wang
2019-04-15 12:15 ` [7/7] dmaengine: sprd: Add interrupt support for " Baolin Wang
2019-04-15 12:15 ` [PATCH 7/7] " Baolin Wang
2019-04-29 12:01 ` [7/7] " Vinod Koul
2019-04-29 12:01 ` [PATCH 7/7] " Vinod Koul
2019-04-29 12:11 ` [7/7] " Baolin Wang
2019-04-29 12:11 ` [PATCH 7/7] " Baolin Wang
2019-04-29 14:10 ` [7/7] " Vinod Koul
2019-04-29 14:10 ` [PATCH 7/7] " Vinod Koul
2019-04-30 5:37 ` [7/7] " Baolin Wang
2019-04-30 5:37 ` [PATCH 7/7] " Baolin Wang
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