From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
To: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org, Frank Rowand <frowand.list@gmail.com>,
"moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE"
<linux-arm-kernel@lists.infradead.org>,
linux-wireless <linux-wireless@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
linux-arm-msm <linux-arm-msm@vger.kernel.org>,
"open list:DMA GENERIC OFFLOAD ENGINE SUBSYSTEM"
<dmaengine@vger.kernel.org>,
etnaviv@lists.freedesktop.org,
dri-devel <dri-devel@lists.freedesktop.org>,
xen-devel@lists.xenproject.org, linux-tegra@vger.kernel.org,
Linux Media Mailing List <linux-media@vger.kernel.org>,
linux-pci@vger.kernel.org, Matthias Brugger <mbrugger@suse.com>,
Robin Murphy <robin.murphy@arm.com>,
Florian Fainelli <f.fainelli@gmail.com>,
james.quinlan@broadcom.com, Stefan Wahren <wahrenst@gmx.net>,
Dan Williams <dan.j.williams@intel.com>,
freedreno <freedreno@lists.freedesktop.org>
Subject: Re: [PATCH 00/11] of: Fix DMA configuration for non-DT masters
Date: Wed, 25 Sep 2019 16:52:59 +0200 [thread overview]
Message-ID: <d1a31a2ec8eb2f226b1fb41f6c24ffb47c3bf7c7.camel@suse.de> (raw)
In-Reply-To: <CAL_Jsq+v+svTyna7UzQdRVqfNc5Z_bgWzxNRXv7-Wqv3NwDu2g@mail.gmail.com>
[-- Attachment #1.1: Type: text/plain, Size: 2723 bytes --]
On Tue, 2019-09-24 at 16:59 -0500, Rob Herring wrote:
> On Tue, Sep 24, 2019 at 1:12 PM Nicolas Saenz Julienne
> <nsaenzjulienne@suse.de> wrote:
> > Hi All,
> > this series tries to address one of the issues blocking us from
> > upstreaming Broadcom's STB PCIe controller[1]. Namely, the fact that
> > devices not represented in DT which sit behind a PCI bus fail to get the
> > bus' DMA addressing constraints.
> >
> > This is due to the fact that of_dma_configure() assumes it's receiving a
> > DT node representing the device being configured, as opposed to the PCIe
> > bridge node we currently pass. This causes the code to directly jump
> > into PCI's parent node when checking for 'dma-ranges' and misses
> > whatever was set there.
> >
> > To address this I create a new API in OF - inspired from Robin Murphys
> > original proposal[2] - which accepts a bus DT node as it's input in
> > order to configure a device's DMA constraints. The changes go deep into
> > of/address.c's implementation, as a device being having a DT node
> > assumption was pretty strong.
> >
> > On top of this work, I also cleaned up of_dma_configure() removing its
> > redundant arguments and creating an alternative function for the special
> > cases
> > not applicable to either the above case or the default usage.
> >
> > IMO the resulting functions are more explicit. They will probably
> > surface some hacky usages that can be properly fixed as I show with the
> > DT fixes on the Layerscape platform.
> >
> > This was also tested on a Raspberry Pi 4 with a custom PCIe driver and
> > on a Seattle AMD board.
>
> Humm, I've been working on this issue too. Looks similar though yours
> has a lot more churn and there's some other bugs I've found.
That's good news, and yes now that I see it, some stuff on my series is overly
complicated. Specially around of_translate_*().
On top of that, you removed in of_dma_get_range():
- /*
- * At least empty ranges has to be defined for parent node if
- * DMA is supported
- */
- if (!ranges)
- break;
Which I assumed was bound to the standard and makes things easier.
> Can you test out this branch[1]. I don't have any h/w needing this,
> but wrote a unittest and tested with modified QEMU.
I reviewed everything, I did find a minor issue, see the patch attached.
Also I tested your branch both on an RPi4, with a PCI device that depends on
these changes and by comparing the OF debugs logs on a Layerscape board which
uses dma-ranges, dma-coherent and IOMMU. All works as expected.
Will you send this series for v5.5? Please keep me in the loop, I'll review and
test the final version.
Regards,
Nicolas
[-- Attachment #1.2: 0001-of-device-do-not-bail-of_dma_configure-when-force_dm.patch --]
[-- Type: text/x-patch, Size: 959 bytes --]
From 26d51853c25c04c28dbc09061951a93c102dabcd Mon Sep 17 00:00:00 2001
From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Date: Wed, 25 Sep 2019 16:26:57 +0200
Subject: [PATCH] of: device: do not bail of_dma_configure() when force_dma is
set
Some Xen devices call of_dma_configure() without an actual DT node in
order for it to set its 'dma_ops'. That's the original intent of
'force_dma', honor that behaviour.
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
---
drivers/of/device.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/drivers/of/device.c b/drivers/of/device.c
index a45261e21144..7bc00f72468f 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -100,8 +100,6 @@ int of_dma_configure(struct device *dev, struct device_node *parent, bool force_
np = dev->of_node;
if (!np)
np = parent;
- if (!np)
- return -ENODEV;
ret = of_dma_get_range(np, &dma_addr, &paddr, &size);
if (ret < 0) {
--
2.23.0
[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 488 bytes --]
next prev parent reply other threads:[~2019-09-25 14:53 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-24 18:12 [PATCH 00/11] of: Fix DMA configuration for non-DT masters Nicolas Saenz Julienne
2019-09-24 18:12 ` [PATCH 01/11] of: address: clean-up unused variable in of_dma_get_range() Nicolas Saenz Julienne
2019-09-24 18:12 ` [PATCH 02/11] of: base: introduce __of_n_*_cells_parent() Nicolas Saenz Julienne
2019-09-24 18:12 ` [PATCH 03/11] of: address: use parent DT node in bus->count_cells() Nicolas Saenz Julienne
2019-09-24 18:12 ` [PATCH 04/11] of: address: introduce of_translate_dma_address_parent() Nicolas Saenz Julienne
2019-09-24 18:12 ` [PATCH 05/11] of: expose __of_get_dma_parent() to OF subsystem Nicolas Saenz Julienne
2019-09-24 18:12 ` [PATCH 06/11] of: address: use parent OF node in of_dma_get_range() Nicolas Saenz Julienne
2019-09-24 18:12 ` [PATCH 07/11] dts: arm64: layerscape: add dma-ranges property to qoric-mc node Nicolas Saenz Julienne
2019-10-14 8:28 ` Shawn Guo
2019-10-14 10:00 ` Nicolas Saenz Julienne
2019-10-14 11:09 ` Shawn Guo
2019-09-24 18:12 ` [PATCH 08/11] dts: arm64: layerscape: add dma-ranges property to pcie nodes Nicolas Saenz Julienne
2019-10-14 8:29 ` Shawn Guo
2019-09-24 18:12 ` [PATCH 09/11] of: device: remove comment in of_dma_configure() Nicolas Saenz Julienne
2019-09-24 18:12 ` [PATCH 10/11] of: device: introduce of_dma_configure_parent() Nicolas Saenz Julienne
2019-09-24 18:12 ` [PATCH 11/11] of: simplify of_dma_config()'s arguments Nicolas Saenz Julienne
2019-09-24 21:59 ` [PATCH 00/11] of: Fix DMA configuration for non-DT masters Rob Herring
2019-09-25 14:52 ` Nicolas Saenz Julienne [this message]
2019-09-25 15:09 ` Robin Murphy
2019-09-25 15:30 ` Nicolas Saenz Julienne
2019-09-25 16:16 ` Rob Herring
2019-09-25 16:52 ` Robin Murphy
2019-09-25 21:33 ` Rob Herring
2019-09-26 10:44 ` Nicolas Saenz Julienne
2019-09-26 11:20 ` Robin Murphy
2019-10-02 18:28 ` Florian Fainelli
2019-09-25 16:07 ` Rob Herring
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=d1a31a2ec8eb2f226b1fb41f6c24ffb47c3bf7c7.camel@suse.de \
--to=nsaenzjulienne@suse.de \
--cc=dan.j.williams@intel.com \
--cc=devicetree@vger.kernel.org \
--cc=dmaengine@vger.kernel.org \
--cc=dri-devel@lists.freedesktop.org \
--cc=etnaviv@lists.freedesktop.org \
--cc=f.fainelli@gmail.com \
--cc=freedreno@lists.freedesktop.org \
--cc=frowand.list@gmail.com \
--cc=james.quinlan@broadcom.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-media@vger.kernel.org \
--cc=linux-pci@vger.kernel.org \
--cc=linux-tegra@vger.kernel.org \
--cc=linux-wireless@vger.kernel.org \
--cc=mbrugger@suse.com \
--cc=robh+dt@kernel.org \
--cc=robin.murphy@arm.com \
--cc=wahrenst@gmx.net \
--cc=xen-devel@lists.xenproject.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).