The logic in this file is rather convoluted, but essentially:
1. region type 0 is SDRAM
2. referring to the code fragment
if (set_fbmem_region_type(&rg, OMAPFB_MEMTYPE_SDRAM,
sdram_start, sdram_size) < 0 ||
(rg.type != OMAPFB_MEMTYPE_SDRAM))
continue;
- if rg.type is not OMAPFB_MEMTYPE_SDRAM, set_fbmem_region_type()
returns zero immediately (since rg.type is non-zero), and so we
'continue'.
- if rg.type is OMAPFB_MEMTYPE_SDRAM, and rg.paddr is zero,
we fall through.
- if rg.type is OMAPFB_MEMTYPE_SDRAM, and the region lies within
SDRAM, we fall through.
- if rg.type is OMAPFB_MEMTYPE_SDRAM, and the region is not within
SDRAM, we 'continue'.
3. check_fbmem_region seems unnecessary.
- we know rg.type is OMAPFB_MEMTYPE_SDRAM
- we can check rg.size independently
- bootmem_reserve() can check for overlapping reservations itself
- we've already validated that the requested region lies within SDRAM.
4. avoid BUG()ing if the region entry is already set; print an error,
and mark the configuration invalid - at least we'll continue booting
so the error message has a chance of being logged/visible via serial
console.
With these changes in place, it makes the code much easier to understand
and hence easier to convert to LMB.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
a1af0fbbba