On 2014-12-01 18:42, Guenter Roeck wrote: > On Mon, Dec 01, 2014 at 09:38:09AM -0800, Feng Kan wrote: >> On Mon, Dec 1, 2014 at 9:29 AM, Stefan Agner <stefan@xxxxxxxx> wrote: >> > On 2014-12-01 18:15, Feng Kan wrote: >> >> On Mon, Dec 1, 2014 at 9:03 AM, Stefan Agner <stefan@xxxxxxxx> wrote: >> >>> This patch adds an optional property which allows to specify the >> >>> reset source priority. This priority is used by the kernel restart >> >>> handler call chain to sort out the proper reset/restart method. >> >>> Depending on the power design of a board or other machine/board >> >>> specific peculiarity, it is not possible to pick a generic priority. >> >>> >> >>> Signed-off-by: Stefan Agner <stefan@xxxxxxxx> >> >>> --- >> >>> Documentation/devicetree/bindings/power/reset/syscon-reboot.txt | 3 +++ >> >>> drivers/power/reset/syscon-reboot.c | 5 ++++- >> >>> 2 files changed, 7 insertions(+), 1 deletion(-) >> >>> >> >>> diff --git a/Documentation/devicetree/bindings/power/reset/syscon-reboot.txt b/Documentation/devicetree/bindings/power/reset/syscon-reboot.txt >> >>> index 1190631..ee41d9c 100644 >> >>> --- a/Documentation/devicetree/bindings/power/reset/syscon-reboot.txt >> >>> +++ b/Documentation/devicetree/bindings/power/reset/syscon-reboot.txt >> >>> @@ -11,6 +11,9 @@ Required properties: >> >>> - offset: offset in the register map for the reboot register (in bytes) >> >>> - mask: the reset value written to the reboot register (32 bit access) >> >>> >> >>> +Optional properties: >> >>> +- priority: define the priority of the reset (0-255, defaults to 128) >> >>> + >> >>> Default will be little endian mode, 32 bit access only. >> >>> >> >>> Examples: >> >>> diff --git a/drivers/power/reset/syscon-reboot.c b/drivers/power/reset/syscon-reboot.c >> >>> index 815b901..3060d6b 100644 >> >>> --- a/drivers/power/reset/syscon-reboot.c >> >>> +++ b/drivers/power/reset/syscon-reboot.c >> >>> @@ -67,8 +67,11 @@ static int syscon_reboot_probe(struct platform_device *pdev) >> >>> if (of_property_read_u32(pdev->dev.of_node, "mask", &ctx->mask)) >> >>> return -EINVAL; >> >>> >> >>> - ctx->restart_handler.notifier_call = syscon_restart_handle; >> >>> ctx->restart_handler.priority = 128; >> >>> + of_property_read_u32(pdev->dev.of_node, "priority", >> >>> + &ctx->restart_handler.priority); >> >> >> >> What is this for? >> > >> > What do you mean? The moved line "ctx->restart_handler.notifier_call = >> > syscon_restart_handle;"? When one reads the diff, it looks like that >> > line was moved, in fact I tried to keep the of_property_read function >> > calls together. But I had to move the assignation of the default >> > priority in front of restart_handler.priority. That's what is the >> > outcome... >> >> I believe Guenter explained above already. Actually this help to solve one of >> my problem. Thanks. > > Since Mark doesn't seem to be happy with the idea of making the priority > dt-configurable, the alternative might be to just set a higher priority for > syscon triggered resets, as suggested by Stefan. Not as flexible, but it > should be ok for most use cases. > I read the other branch of this thread too, but IMHO, this would be the best solution for now. It's a one line change and does the job. After all, we have that priority for a reason, it doesn't makes sense having all of them at a common default. As mentioned in an other reply, I think it is especially reasonable to configure the syscon-reboot driver a bit higher, since this driver is more likely to be used for a dedicated reboot feature provided by the SoC, which usually is the preferred one. If it happens one day that a SoC ends up with conflicting priorities or other priority odds, we can add the DT support then... What do you think, can I go with that for now? (Guenter, Feng, Mark...?) -- Stefan -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
