On 31.05.2018, at 21:48, Martin Kelly mkelly@xevo.com wrote:
On 05/31/2018 11:15 AM, klaus.goger@theobroma-systems.com wrote:
Hi Martin,
On 31.05.2018, at 19:49, Martin Kelly mkelly@xevo.com wrote:
On 05/23/2018 11:34 AM, Martin Kelly wrote:
On 05/17/2018 05:01 AM, Maxime Ripard wrote:
On Tue, May 01, 2018 at 05:46:41PM -0700, Martin Kelly wrote:
Currently, sunxi-common.h ignores CONFIG_DEFAULT_FDT_FILE and assumes the kernel fdtfile and the u-boot devicetree names are the same. Although this is typically the case, sometimes you might want to customize one of these differently, so it's useful to allow them to be different.
Add logic in sunxi-common.h to respect CONFIG_DEFAULT_FDT_FILE, if set, and default to the values it currently uses.
Signed-off-by: Martin Kelly mkelly@xevo.com
Acked-by: Maxime Ripard maxime.ripard@bootlin.com
Maxime
(ping)
(ping again)
Can we get this patch merged?
The else branch will never be selected. CONFIG_DEFAULT_FDT_FILE will be set to “” if not set by your defconfig.
Thanks for noticing this; unfortunately you are right. I thought I tested this, but it was in the context of a larger build and I missed it.
It looks like we have two options:
(a) Test for empty string in preprocessor language. This is quite ugly and has some gotchas but should be doable (e.g. https://stackoverflow.com/questions/3781520/how-to-test-if-preprocessor-symb...).
(b) Always use the value of CONFIG_DEFAULT_FDT_FILE and stop using CONFIG_DEFAULT_DEVICE_TREE as a default. In each board file, explicitly set CONFIG_DEFAULT_FDT_FILE to its current default. This is what other boards are doing.
I favor (b). If others are in favor, I'll submit a patch for it.
I run into the same issue for the rockchip architecture[1]. After giving up on finding a rock-solid solution for detecting the emtpy string I decided to go with your option (b). Another solution would be to hide CONFIG_DEFAULT_DEVICE_TREE behind a Kconfig bool so it would not be defined until something like CONFIG_FDT_FILE is selected. But in favour of having U-Boot devicetree decoupled from any OS fdt I still prefer option (b).