On 04/12/2016 08:39 AM, Thierry Reding wrote:
On Mon, Apr 11, 2016 at 12:47:23PM -0600, Stephen Warren wrote:
On 04/11/2016 12:32 PM, Rob Herring wrote:
On Mon, Apr 11, 2016 at 11:05 AM, Stephen Warren <swarren@xxxxxxxxxxxxx> wrote:
On 04/11/2016 08:01 AM, Thierry Reding wrote:
From: Thierry Reding <treding@xxxxxxxxxx>
When Tegra124 support was first merged the unit-addresses of all devices
were listed with a "0," prefix to encode the reg property's second cell.
It turns out that this notation is not correct, and the "," separator is
only used to separate fields in the unit address (such as the device and
function number in PCI devices), not individual cells for addresses with
more than one cell.
diff --git a/arch/arm/boot/dts/tegra124-jetson-tk1.dts
b/arch/arm/boot/dts/tegra124-jetson-tk1.dts
- gpu@0,57000000 {
+ gpu@57000000 {
/*
* Node left disabled on purpose - the bootloader will
enable
* it after having set the VPR up
So the bootloader doesn't actually do that for the new node name at present.
I have written a patch to make it do so, but haven't sent it yet since I
wrote it in the middle of a large cleanup of U-Boot. I expect I can shuffle
it to the front of the series and send it soon though. Without a new
bootloader that contains this change, IIUC all graphics will be
non-operative if this change is applied.
Then you should leave this one alone for a while.
I also found this looking at u-boot:
arch/arm/dts/tegra124.dtsi: gpu@57000000 {
FWIW, that's because the U-Boot DTs use #address-cells=<1> on this chip so
there was no question of using commas in the unit address or not. That may
have been because U-Boot imported the DTs (or parts of them) from Linux
before Linux switched to #address-cells=<2> on this chip.
I thought the reason had been that U-Boot didn't support any more than
32-bits for addresses on 32-bit ARM anyway, hence we never bothered to
sync with the kernel DTS files regarding #address-cells.
Ah, that has also been historically true. It isn't true any more
(excepting any latent bugs, which do keep cropping up).
Technically it would be possible for someone to write a DTS file with a
GPU node with yet another name (the binding after all doesn't specify
what the node name should be) so I think better matching would be safer
in any case.
Yes, that does seem better. I'll try and get that one patch out today,
assuming I can rebase it to the bottom of the stack easily. FYI, U-Boot
is now on a 2-month release cycle, so the next scheduled release is
v2016.05 on May 9, and the merge window just closed for that release.
It's arguable this is a bug fix though...
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