[PATCH 1/2] ARM: dts: armada388-clearfog: enable spi flash

[linux@armlinux.org.uk (Russell King - ARM Linux)]

On Thu, Jun 28, 2018 at 01:47:30PM +0300, Baruch Siach wrote:
> Hi Russell,
> 
> On Thu, Jun 28, 2018 at 11:33:20AM +0100, Russell King - ARM Linux wrote:
> > On Thu, Jun 28, 2018 at 01:07:59PM +0300, Baruch Siach wrote:
> > > Thanks for reviewing.
> > > 
> > > On Thu, Jun 28, 2018 at 10:51:14AM +0100, Russell King - ARM Linux wrote:
> > > > On Thu, Jun 28, 2018 at 10:13:35AM +0300, Baruch Siach wrote:
> > > > > The SolidRun Armada 388 SOM has the SPI flash populated by default
> > > > > unless the customer explicitly asks otherwise. Enable support by
> > > > > default.
> > > > 
> > > > Are you sure about that - at least some of my boards do not have the
> > > > SPI flash populated.
> > > > 
> > > > &spi1 {
> > > >         /* The microsom has an optional W25Q32 on board, connected to CS0 */
> > > > ...
> > > > &spi1 {
> > > >         /*
> > > >          * Add SPI CS pins for clearfog:
> > > >          * CS0: W25Q32 (not populated on uSOM)
> > > 
> > > I should update this line as well, I guess.
> > > 
> > > >          * CS1: PIC microcontroller (Pro models)
> > > >          * CS2: mikrobus
> > > >          */
> > > > 
> > > > I wouldn't have written "not populated on uSOM" without having first
> > > > taken the uSOM off and physically checked.
> > > 
> > > Are these production SOMs or development/engineering samples?
> > 
> > I don't remember.
> > 
> > > Ilya Viten from the SolidRun commercial department told me that all production 
> > > SOMs that were shipped to customers have the SPI flash populated.
> > 
> > Yes, Jon confirms that.
> > 
> > > This is just the default value for the common case.
> > 
> > Has it been tested with boards that don't have the SPI flash populated?
> > That needs to happen to make sure that this doesn't cause a regression.
> 
> I don't have such a SOM handy. I can try to "produce" one next week.
> 
> I tested a modified DT with the 'reg' property set to 1 to simulate an 
> unpopulated SPI flash. The driver probe seems to fail gracefully:
> 
>   m25p80 spi1.1: unrecognized JEDEC id bytes: ff, ff, ff
> 
> Is this test sufficient to ensure the safety of this patch?

Yes, that's fine, thanks for checking.

Acked-by: Russell King <rmk+kernel@armlinux.org.uk>

Gregory, please add my acked-by to your hasty commit, thanks.

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