boot failure with __iounmap changes in v3.3

Nicolas Pitre nicolas.pitre at linaro.org
Mon Mar 12 21:35:11 UTC 2012


On Mon, 12 Mar 2012, jonsmirl at gmail.com wrote:

> On Mon, Mar 12, 2012 at 4:18 PM, Nicolas Pitre <nicolas.pitre at linaro.org> wrote:
> > On Mon, 12 Mar 2012, jonsmirl at gmail.com wrote:
> >
> >> I'm working on getting out of tree support for the NXP LPC31xx
> >> ARM926EJS based CPUs ready for submission. Everything was working fine
> >> on v3.2 but I lost the ability to boot with v3.3. The boot failure is
> >> very early in the boot process. I did a bisect and came up with:
> >>
> >> [6ee723a6570a897208b76ab3e9a495e9106b2f8c] ARM: simplify __iounmap()
> >> when dealing with section based mapping
> >>
> >> I tried to revert it but there have been a bunch of edits in this
> >> file. Not sure how to go about debugging this.
> >
> > The first thing to look for is any overlap in the virtual memory ranges
> > used in your struct map_desc array.  No overlap is allowed anymore.
> 
> There appear to be overlaps. I'll have to study things for a while to
> figure out how to eliminate them. This is from a three year old NXP
> BSP. We have a product based on the CPU and want to use a more recent
> kernel.
> 
> They've defined multiple large peripheral regions...
> 
> /* APB4 address range*/
> #define IO_APB4_PHYS      (0x17000000)
> #define IO_APB4_SIZE      (0x00001000)
> 
> 	{
> 		.virtual	= io_p2v(IO_APB4_PHYS),
> 		.pfn		= __phys_to_pfn(IO_APB4_PHYS),
> 		.length		= IO_APB4_SIZE,
> 		.type		= MT_DEVICE
> 	},
> 
> and then declared various devices inside of them...
> 
> /* DMA registers address range*/
> #define DMA_PHYS          (0x17000000)
> #define IO_DMA_REG_PHYS  (DMA_PHYS)
> #define IO_DMA_REG_SIZE  (0x0000800)
> 
> 	{
> 		.virtual	= io_p2v(IO_DMA_REG_PHYS),
> 		.pfn		= __phys_to_pfn(IO_DMA_REG_PHYS),
> 		.length		= IO_DMA_REG_SIZE,
> 		.type		= MT_DEVICE
> 	},

Just get rid of the map_desc entryes corresponding to subsets of a 
larger entry that already covers them and you should be fine.


Nicolas


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