Re: [PATCH] ARM: tegra: fix erroneous address in dts

From: Stephen Warren
Date: Fri Jul 15 2016 - 12:01:32 EST


On 07/15/2016 03:37 AM, Ralf Ramsauer wrote:
On 07/15/2016 12:02 AM, Thierry Reding wrote:
On Thu, Jul 14, 2016 at 06:48:57PM +0200, Ralf Ramsauer wrote:
c90bb7b enabled the high speed UARTs of the Jetson TK1. The address
specification inside the dts is wrong. Fix it and use the correct
address.

Fixes: c90bb7b9b9 ("ARM: tegra: Add high speed UARTs to Jetson TK1 device tree")
Signed-off-by: Ralf Ramsauer <ralf@xxxxxxxxxxxxxxxxxxxxxx>
---
arch/arm/boot/dts/tegra124-jetson-tk1.dts | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

These addresses are correct. The 0, prefix was dropped from the unit
address in commit b5896f67ab3c ("ARM: tegra: Remove commas from unit
addresses on Tegra124").

What's the problem that you're seeing? What's not working for you?
>
I cannot find b5896f67ab3c neither in swarren's tree nor in linux
upstream. But there's d0bc5aaf890 in swarren's linux-tegra tree that
matches your described changes and was committed on 1st of July. But
this patch is not upstream yet, while the other patch is.

The fix is in linux-next, and will be in mainline soon I expect.

My github linux-tegra.git isn't relevant since it's just my own personal dev branch, but for reference, the commit is there since it's based on linux-next.

Have a look at mainline tegra124-jetson-tk1.dts, there the addresses are
erroneous as they still use the 0, annotation. And I just realised, that
somehow, upstream patch c90bb7b slightly differs from my initial patch
[1] on the mailing list.

Your patch should probably be CC: stable so that existing kernel versions get fixed. That said, I'd argue that since the original patch never actually had any effect since it applied to the wrong node, the best fix for stable kernels is simply to revert it rather than fixing it, to avoid the potential for behaviour changes and regressions. Starting with kernel 4.8 (I think), that patch will begin to have actual effect.