Re: [PATCH] clk: mvebu: Add clk support for the orion5x SoC mv88f5181

[Stephen Boyd]

On 09/21, Gregory CLEMENT wrote:
> Hi Stephen,
>  
>  On mar., sept. 20 2016, Stephen Boyd <sboyd@xxxxxxxxxxxxxx> wrote:
> 
> > On 09/20, Gregory CLEMENT wrote:
> >> From: Jamie Lentin <jm@xxxxxxxxxxxx>
> >> 
> >> Referring to the u-boot sources for the Netgear WNR854T, add support
> >> for the mv88f5181.
> >> 
> >> [gregory.clement@xxxxxxxxxxxxxxxxxx: fix commit title]
> >> Signed-off-by: Jamie Lentin <jm@xxxxxxxxxxxx>
> >> Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
> >> Acked-by: Rob Herring <robh@xxxxxxxxxx>
> >> Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
> >> ---
> >> 
> >> Hi Stephen and Mike,
> >> 
> >> do you agree to give your acked-by on this patch. It is part of a
> >> convertion of old orion5x Socv to the device tree. If you acked-by
> >> this one, then I will be able to take it in my tree and avoiding
> >> breaking the git bisect.
> >
> > Is the problem that we're changing some dts files somewhere and
> > those platforms would stop booting if this change wasn't present?
> > Given that we're adding a new compatible it seems like we're
> > adding new SoC support, so having the clk patch and the dts patch
> > come together in -next via a merge instead of basing the dts
> > patch on top of the clk patch would be how things are normally
> > done.
> 
> The problem appear if the dts for the board using the clock driver is
> merged in Linus tree before the support in the driver. At this point the
> board won't be able to boot.
> 
> It introduces a hole in the git bisect between the merge of the clock
> subsystem and the arm-soc subsystem.

Ok so that sounds like the typical case where a new SoC/board is
supported and the dts files don't do anything useful until the
driver support lands. We don't usually care about bisection
problems here because the board doesn't transition from 'working'
to 'not working'. It only transitions from 'not working' to
'working' once the clk driver and the dts files are both present
in the tree.

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