Re: [RFC PATCH 1/5] OMAP3:I2C: Add device tree nodes for beagle board
From: Grant Likely <hidden>
Date: 2011-07-20 23:14:05
Also in:
linux-arm-kernel, linux-devicetree, linux-omap
On Wed, Jul 20, 2011 at 4:33 PM, Shawn Guo [off-list ref] wrote:
On Wed, Jul 20, 2011 at 12:55:13PM -0600, Grant Likely wrote:quoted
On Wed, Jul 20, 2011 at 07:04:20PM +0800, Shawn Guo wrote:quoted
quoted
Mostly consistency. Most of the experience we have with the flattened device tree up to this point hasn't bothered with the 'status' property. It is only when AMP and hypervisors cam online that it became important to use a status property, and that only when the kernel needs to be told that the device does indeed exist, but it must not be touched. I'd like to continue that pattern for new DT users with the default assumption that a device is enabled unless the board .dts explicitly disables it.[...]quoted
Besides the bothering that we have to list so many unused controllers in individual board dts file, it's also hard to tell which controllers are actually available on the board. People have to look at imx53.dts to get a full list and then exclude the ones in imx53-<board>.dts as "disabled". And if we go the way opposite, adding "disabled" status for everyone in imx53.dts, we will only need to specify the peripherals that are actually available on board with "okay" status in imx53-<board>.dts. And it's much more clear for people to see what peripherals are available on individual board. So I'm going the way than you suggested. Please let me know if you strongly dislikes it.Yes, I strongly dislike it. I understand the concern, but at this early stage with converting to device tree I think consistency between platforms is more important. We can talk about the issue at Linaro Connect in 2 weeks, but in the mean time please use the enabled-by-default/explicitly-disabled pattern.Okay, hope you will not ask me to use the opposite pattern when you actually see the patch :)
:-) g.