From: Rob Herring <robh@kernel.org>
To: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Cc: devicetree@vger.kernel.org,
Florian Fainelli <f.fainelli@gmail.com>,
Geert Uytterhoeven <geert+renesas@glider.be>,
Arnd Bergmann <arnd@arndb.de>, PCI <linux-pci@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Christoph Hellwig <hch@infradead.org>,
Marek Vasut <marek.vasut@gmail.com>,
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
Oza Pawandeep <oza.oza@broadcom.com>,
Stefan Wahren <wahrenst@gmx.net>,
Simon Horman <horms+renesas@verge.net.au>,
Frank Rowand <frowand.list@gmail.com>,
"moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE"
<linux-arm-kernel@lists.infradead.org>,
Robin Murphy <robin.murphy@arm.com>
Subject: Re: [PATCH 05/11] of: Ratify of_dma_configure() interface
Date: Mon, 30 Sep 2019 16:24:20 -0500 [thread overview]
Message-ID: <CAL_JsqLnKxuQRR3sGGtXF3nwwDx7DOONPPYz37ROk7u_+cxRug@mail.gmail.com> (raw)
In-Reply-To: <95f8dabea99f104336491281b88c04b58d462258.camel@suse.de>
On Mon, Sep 30, 2019 at 8:32 AM Nicolas Saenz Julienne
<nsaenzjulienne@suse.de> wrote:
>
> On Mon, 2019-09-30 at 05:57 -0700, Christoph Hellwig wrote:
> > On Thu, Sep 26, 2019 at 07:24:49PM -0500, Rob Herring wrote:
> > > -int of_dma_configure(struct device *dev, struct device_node *np, bool
> > > force_dma)
> > > +int of_dma_configure(struct device *dev, struct device_node *parent, bool
> > > force_dma)
> >
> > This creates a > 80 char line.
> >
> > > {
> > > u64 dma_addr, paddr, size = 0;
> > > int ret;
> > > bool coherent;
> > > unsigned long offset;
> > > const struct iommu_ops *iommu;
> > > + struct device_node *np;
> > > u64 mask;
> > >
> > > + np = dev->of_node;
> > > + if (!np)
> > > + np = parent;
> > > + if (!np)
> > > + return -ENODEV;
> >
> > I have to say I find the older calling convention simpler to understand.
> > If we want to enforce the invariant I'd rather do that explicitly:
> >
> > if (dev->of_node && np != dev->of_node)
> > return -EINVAL;
>
> As is, this would break Freescale Layerscape fsl-mc bus' dma_configure():
This may break PCI too for devices that have a DT node.
> static int fsl_mc_dma_configure(struct device *dev)
> {
> struct device *dma_dev = dev;
>
> while (dev_is_fsl_mc(dma_dev))
> dma_dev = dma_dev->parent;
>
> return of_dma_configure(dev, dma_dev->of_node, 0);
> }
>
> But I think that with this series, given the fact that we now treat the lack of
> dma-ranges as a 1:1 mapping instead of an error, we could rewrite the function
> like this:
Now, I'm reconsidering allowing this abuse... It's better if the code
which understands the bus structure in DT for a specific bus passes in
the right thing. Maybe I should go back to Robin's version (below).
OTOH, the existing assumption that 'dma-ranges' was in the immediate
parent was an assumption on the bus structure which maybe doesn't
always apply.
diff --git a/drivers/of/device.c b/drivers/of/device.c
index a45261e21144..6951450bb8f3 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -98,12 +98,15 @@ int of_dma_configure(struct device *dev, struct
device_node *parent, bool force_
u64 mask;
np = dev->of_node;
- if (!np)
- np = parent;
+ if (np)
+ parent = of_get_dma_parent(np);
+ else
+ np = of_node_get(parent);
if (!np)
return -ENODEV;
- ret = of_dma_get_range(np, &dma_addr, &paddr, &size);
+ ret = of_dma_get_range(parent, &dma_addr, &paddr, &size);
+ of_node_put(parent);
if (ret < 0) {
/*
* For legacy reasons, we have to assume some devices need
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next prev parent reply other threads:[~2019-09-30 21:24 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-27 0:24 [PATCH 00/11] of: dma-ranges fixes and improvements Rob Herring
2019-09-27 0:24 ` [PATCH 01/11] of: Remove unused of_find_matching_node_by_address() Rob Herring
2019-09-27 9:17 ` Geert Uytterhoeven
2019-09-30 12:49 ` Christoph Hellwig
2019-09-27 0:24 ` [PATCH 02/11] of: Make of_dma_get_range() private Rob Herring
2019-09-27 9:18 ` Geert Uytterhoeven
2019-09-30 12:53 ` Christoph Hellwig
2019-09-27 0:24 ` [PATCH 03/11] of: address: Report of_dma_get_range() errors meaningfully Rob Herring
2019-09-27 9:15 ` Geert Uytterhoeven
2019-09-30 12:54 ` Christoph Hellwig
2019-09-27 0:24 ` [PATCH 04/11] of/unittest: Add dma-ranges address translation tests Rob Herring
2019-09-27 0:24 ` [PATCH 05/11] of: Ratify of_dma_configure() interface Rob Herring
2019-09-30 12:57 ` Christoph Hellwig
2019-09-30 13:32 ` Nicolas Saenz Julienne
2019-09-30 21:24 ` Rob Herring [this message]
2019-10-01 15:43 ` Nicolas Saenz Julienne
2019-10-04 1:53 ` Rob Herring
2019-10-07 17:51 ` Nicolas Saenz Julienne
2019-09-27 0:24 ` [PATCH 06/11] of/address: Introduce of_get_next_dma_parent() helper Rob Herring
2019-09-27 9:24 ` Geert Uytterhoeven
2019-09-27 0:24 ` [PATCH 07/11] of: address: Follow DMA parent for "dma-coherent" Rob Herring
2019-09-27 0:24 ` [PATCH 08/11] of: Factor out #{addr,size}-cells parsing Rob Herring
2019-09-27 9:27 ` Geert Uytterhoeven
2019-09-27 0:24 ` [PATCH 09/11] of: Make of_dma_get_range() work on bus nodes Rob Herring
2019-09-27 0:24 ` [PATCH 10/11] of/address: Translate 'dma-ranges' for parent nodes missing 'dma-ranges' Rob Herring
2019-09-27 0:24 ` [PATCH 11/11] of/address: Fix of_pci_range_parser_one translation of DMA addresses Rob Herring
2019-09-29 11:16 ` [PATCH 00/11] of: dma-ranges fixes and improvements Arnd Bergmann
2019-09-30 8:20 ` Christoph Hellwig
2019-09-30 8:56 ` Thierry Reding
2019-09-30 9:55 ` Robin Murphy
2019-09-30 13:35 ` Thierry Reding
2019-09-30 9:20 ` Nicolas Saenz Julienne
2019-09-30 12:40 ` Marek Vasut
2019-09-30 12:52 ` Robin Murphy
2019-09-30 12:54 ` Marek Vasut
2019-09-30 13:05 ` Robin Murphy
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